Class D amplifiers

 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13644
Registered: May-04
.

If you didn't see this in the newsletter, https://www.ecoustics.com/electronics/products/articles/568486.html




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Platinum Member
Username: Nuck

Post Number: 12477
Registered: Dec-04
I did, and this is a very simple way to describe amplifier function, an excellent piece that I will bookmark for further discussion.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2608
Registered: Feb-07
That describes Class D amplification so even I can understand it.

Interesting that the author's bio links to the Axiom site. They sell a couple of models of D amps that have gotten very good reviews.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2609
Registered: Feb-07
I've also read some really good (and some bad) things about the new Rotel Class D amps.
 

Platinum Member
Username: Nuck

Post Number: 12478
Registered: Dec-04
Ugh. I heard the 500w model, admittadly 2 yrs ago, it was bad. Nothing good. It sounded like a Panasonic 55 D amp on Sammy Hagar tequila gone bad.
 

Gold Member
Username: Nickelbut10

Post Number: 2530
Registered: Jun-07
The brand new one Nuck? I have never been a fan of Rotel, period. But at least their new stuff LOOKS nice.lol
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2610
Registered: Feb-07
I heard a Bel Canto setup a couple years back (the ref 1000s) and I was actually quite blown away by the power and the sound.
 

Platinum Member
Username: Nuck

Post Number: 12479
Registered: Dec-04
The class D amps are kinda led by the ICE output modules which are proven effective in various applications. Some work better than others, but I am yrt to find a lot of jive from any of them. The Channel Islands offerings seem especially dead to me.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2611
Registered: Feb-07
You're heard them Nuck? I was really interested in hearing them at one point.
 

Platinum Member
Username: Nuck

Post Number: 12482
Registered: Dec-04
Always worth a listen david, never turn down a chance.
i heard the channel setup last year in St Louis.
The salesguy wasnt all that hot on it either, with a Sonus Faber concerto speaker setup that should have sounded more natural.
 

Bronze Member
Username: Ezntn

TN

Post Number: 13
Registered: Apr-09
Why your disillusion with Rotel, Nick?
I'm considering replacing my 6 year old Rotel RSX 1065 with their new 15 Series Preamp & 5 x 100 Class D Amp, tho nothing is set in stone quite yet & I'm still looking for better within reason.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2612
Registered: Feb-07
I actually kinda digged my Rotel 2 channel rig when I had it (RA-02/RB-1070). I did find I had to be careful what speakers I paired with it, but usually the combo was clear, precise and sharp, while not being abrasive or fatiguing. With the wrong speakers, well....
 

Gold Member
Username: Nickelbut10

Post Number: 2531
Registered: Jun-07
Bryan- Just not my cup of tea. I have had two of Rotel's power amps in two different systems I have owned now( Just for a day or so at a time) and just felt it sounded too thin and bright to my ears. Just my opinion though. A lot of my buddies like Rotel. Perhaps it was just a synergy mis-match with my system. Or perhaps I never gave it enough of a chance. Never found it overly musical I guess.

Although I had a 5 channel Rotel for a few days, and while I thought it wasn't musical to my ears, I really liked it for home theater. Interesting.

Maybe I have to give it another chance.
 

Gold Member
Username: Nickelbut10

Post Number: 2532
Registered: Jun-07
lol David- I am guessing you mean MA/Rotel combo. *Puke*
 

Platinum Member
Username: Nuck

Post Number: 12491
Registered: Dec-04
Bryan, I am not a Rotel basher by any means. I suppose 'disillusionment' is as apt a description as any.
My hearing is not so great anymore, with a high-tone loss for a long time, thus partly the reason I chose Rotel some time ago. Everything that I listen to would seem a little 'hot' for others, in my experience. However, I found the need to change out the tweeters in PSB Stratus Silver speakers from their metal dome to silk domes from an earlier series, it was getting harsh, and thats to my ears.
Changing to a H/K power amp led me to reinstall the metal domes.

The Rotel power amps have a very definite method of applying attack, particularly with the 1072 cdp that I used. Very agressive and enjoyable for hard rock and metal in particular.
The Rotel D amp setup tht I heard was just like this, but on a mind altering substance, but like PCP, not BC bud for mellowness.

Thats about the best anology that I can come up with right now...
 

Bronze Member
Username: Ezntn

TN

Post Number: 14
Registered: Apr-09
I think David identified the issue, as a match tween speakers & amp. Without auditoining in your listening room, you will never know what makes the best fit. Every quality audio dealer has a very specific set up for listening to either music or for HT, and their acoustic treatments and equipment selections are very specific for just that genre.
Finding that specific synergy between power and the speakers that translate it is ownership of the brass ring.
Depending on its ultimate purpose, music exclusively, or HT, or a combination of both, as is my case, compromises will always be there.

As for analogies Nuck, I'd much rather be in the PNW, tastes and library have gravitated in that direction ....... reckon I'd prefer my system provide the same.
 

Platinum Member
Username: Nuck

Post Number: 12500
Registered: Dec-04
Bryan , please see my comments in Integrated Amps, dude this is something special.
 

Silver Member
Username: Magfan

USA

Post Number: 435
Registered: Oct-07
The Axiom class 'd' stuff is sourced by IR, the company I work for. (full disclosure). I have there reference board out in the garage awaiting a power supply. The 'easy' way out would be to get a brace of batteries rated to the voltage required = 55v. This started with an original exchange with Jan, a couple years ago. I still intend to finish this and only recently actually got the amp.

As for Rotel sound, I also found my RB-1070 was a little 'hot' on top, this with my Magnepan Panels.
I replaced it with an ICE based integrated from PSAudio. They get along much better.

Hypex also gets lots of good press and sells user friendly modules and power supply stuff....One of there hi-power modules / power supply and x-over would probably make a bang up subwoofer amp.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2619
Registered: Feb-07
Interesting Leo.

I liked the sound of my RB-1070 with my Sttafs, but thats because I think the mellowness of the Sttafs tamed the aggressive Rotel top end.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 454
Registered: Mar-04
https://www.ecoustics.com/electronics/products/new/570489.html.

This is one persons opinion:

"I spoke to someone who had actually heard it at a trade show in Asia and he rolled his eyes and said, "Man, when you hear music coming out of absolutely jet-black silence, you'll wonder what have I been listening to for all these years?."
 

Platinum Member
Username: Nuck

Post Number: 12518
Registered: Dec-04
Buuut that's what I have been listening to....
 

Gold Member
Username: Frank_abela

Berkshire UK

Post Number: 3659
Registered: Sep-04
Never quite sure about class D amps. The best implementation I've heard has to be the class T variants but of course Tripath is no more. ICE leaves me cold (pun intended) so the B&Os and Rotels just seem like an exercise rather than an event. I have heard one implementation by Chapter Audio in an isolated show situation which got me fairly interested but there was always this cool sheen, like looking at a Terminator - it looks like a man but you know it's a machine kind of thing. Difficult to describe.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 455
Registered: Mar-04
http://www.jbstanton.com/Resources/M2White2Paper.pdf
 

Platinum Member
Username: Nuck

Post Number: 12585
Registered: Dec-04
I agree Frank. Maybe we need so see a pshrink.
The Channel Island amps are pretty good by all accounts.

good post id. There is a pretty straightforward rundown.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2099
Registered: Jun-05
If you heard the Spectra's, Bel Conto's or the Redwines,or the new Newforce you would'nt say that,even i didnt believe in Class D,when Eddie started touting the Panny,the X-mono's i have handily out perform my the Class A amp section in the Bada 3.8 Purer,even when the the Purer runs balanced and the X-mono's only run unbalanced its still not close.I heard the Bel Conto Ref 1000's mono's up against the big huge Bryston and 600 watt Moon amp,and could'nt believe how badly it beat up on them.
 

Gold Member
Username: Nickelbut10

Post Number: 2566
Registered: Jun-07
FWIW going back to the new Rotel Class D products. Heard their new amps today at Just Hi Fi and it was terrible. Delicate/bright sounding and head crunching. The owner and Manager were both talking to me and both agreed that they can't stand the new Rotel offerings and they have been a dealer for Rotel for over 10 years. On a plus side they both said that the new NAD stuff is way way better. They basically said the same thing as my dealer said. I gave it a quick listened and it sounded nice. Never listened to it too long though. When I asked about NAD's new Class D stuff they Owner said that he hopes they don't go that route as both guys were not a fan of class D at all. I seen the pics of the innards of the Class D technology at it looks like a Motherboard of a PC or a capture card board with dip switches. Doesn't seem like my kind of product. I am sure some higher end companies have better stuff that is Class D.

To add : I listened to the best out door wireless unit I have ever seen. Its not cheap, 1150. But would sure look/sound nice on my back deck.lol
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 582
Registered: Jul-07
I think there are a number of examples of Class D amplication that compete quite nicely against similarly priced Class A or A/B components. Nuforce has a very loyal following, and is very well written in almost any audio publication you care to name. New offerings are coming online regularly. One in particular that has received rave reviews is the monoblocks from Seymour AV.

They are also very environmentally friendly, consuming only a few watts at idle, and are 80% efficient. They typically run very cool and are frequently much smaller than your standard amplifier, which offers a lot of flexibility for placement.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2103
Registered: Jun-05
From what I've been hearing out of the better Class D gear is they have more detail,better soundstaging,especially height and much better bass especialy midbass definition,their also more dynamic than their Class A/B or Class A variants and not like 5 years at the expenense of warmth.The Bel Canto Ref 1000's and Nuforce 9SE are 2 of the best amps I've heard period,and nothing touches the 9SE in the bass and low level detail no matter what it costs.Im a Class A junkie a much more pure sound than Class A/B in most cases,and I've been turned,the X-mono's i have now I'll put them up against any amp up to $2k and guarentee the'll win or nonetheless be vary close and favorible.Plus you guys are taking the worst examples of the technology from people like Rotel and Nad,both of these companies have very little experiance in Class D and just recently started using the technology,if you wanna be fair about comparrisons with Class A/B go find real Class D companies like NuForce,Bel Conto,Channel Islands,Wyred For Sound,Halcro,Jeff Rowland just to name a few,because Rotel and Nad are not real Class D makers,hell they barely make decent Class A/B gear they are pretty low on that level to be frank.Do more research and be fair about it and finding out the best of the technology not the worst examples like Rotel and Nad who can barley make good Class A/B gear that they've been making for over 30 years that they still havent mastered yet.
 

Gold Member
Username: Nickelbut10

Post Number: 2568
Registered: Jun-07
Yeah, the NAD class D M2 looks like a computer MB inside. That scares me. I have no real opinion on the Class D stuff as I have not had even close to enough experience with it, yet. Talking to three audio dealers who have over 25 years experience in running successful Hi Fi shops and playing in multiple bands have all claimed they are not fans of the technology at all. Perhaps being a new technology they havn't had enough experience with it either.

David- Is there a Bel Canto dealer in Ottawa? Doesn't your dealer have it? Have you heard their class D stuff and if so what were your thoughts?

Someone has to explain to me, as an engineer how do you take this technology and make it sound better than Class A?lol. Let me go over that link JV posted again explaining the technology.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2666
Registered: Feb-07
Hey Nick, my local dealer isn't a Bel Canto dealer. They had a pair of Ref 1000's in one time as a trade in. I had a chance to listen to them briefly (along with a BC pre and CDP). To me they sounded very clear and precise. The guy I usually deal with there said that after an extended listening period he found them to fatiguing. Not sure if this is normal trait of class D.

There's another audio shop here in Ottawa that sells the new Rotel class D amps. They're quite a bit more expensive than the regular Rotel A/B amps.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2667
Registered: Feb-07
Oh yeah, there's a dealer here in Ottawa that sells Bel Canto. Oddly enough, it's a computer store.

https://www.themacgroup.ca/store/index.php?c=root&product=eOneRef1000
 

Gold Member
Username: Nickelbut10

Post Number: 2569
Registered: Jun-07
David- Funny that you mention the fatiguing factor with class D. When I asked Chris( the store manager at Just Hi Fi for 12 years now, who plays bass, guitar AND drums in local Kingston bands) held his hands over his ears when I asked him if he liked the new class D amps, and said " Listening to one the other day for more than 20 minutes gave me the biggest headache". "Awful" he said.

Interesting. lol Also an interesting site you posted. Pick up a Bel Canto get a free LCD monitor.LOL!!! Brutal.
 

Gold Member
Username: Nickelbut10

Post Number: 2570
Registered: Jun-07
They sell Nuforce too David.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2111
Registered: Jun-05
Now theres a Ref 1000mkII,they just came out.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 457
Registered: Mar-04
Many of the class D switching amps simply use ice modules, this includes the Bel Canto and Rotel offerings. It would seem based on the white paper that the NAD M2 uses some different technology.
What this translates to in percieved sound quality is another matter but it's specs look good. NAD also uses a switch mode power supply in it's new A/V pre-amp the M15 HD: "A very tightly regulated Switch Mode Supply provides the high current and stable voltages required by the ultra high speed video and audio processing in the new HD circuits".
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 588
Registered: Jul-07
Yes, but what does it sound like. The specs and marketing material always look good.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 589
Registered: Jul-07
In case anyone is interested in somewhat of a fresh face.....

http://www.audiophilia.com/wp/?p=1223

http://www.seymourav.com/amps.asp
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 458
Registered: Mar-04
Those use ice modules too so I don't know how "fresh" they are.

"Yes, but what does it sound like:".

Don't know, I did post up above the impressions of one listener. I also posted the white paper on it which explains what makes it different from so many amps which use the ice modules.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 591
Registered: Jul-07
ID, lots of Class D amps use ICE modules, yes. Many amps have common topologies and components, yet sound completely different. So, I wouldn't think bucketing all of the ICE amps together is particularly useful, and more than grouping all of the EL84 amps.

As to "fresh", all I meant was it was a relative newcomer.
 

Gold Member
Username: Artk

Albany, Oregon USA

Post Number: 9927
Registered: Feb-05
The Seymour's looked pretty interesting to me.
 

Platinum Member
Username: Nuck

Post Number: 12649
Registered: Dec-04
It is all looks till you hear them.
 

Gold Member
Username: Artk

Albany, Oregon USA

Post Number: 9930
Registered: Feb-05
Indeed...then what?
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 592
Registered: Jul-07
Indeed Nuck. I always liked the idea of owning a pair of monoblocks. Maybe someday.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 459
Registered: Mar-04
"So, I wouldn't think bucketing all of the ICE amps together is particularly useful, and more than grouping all of the EL84 amps".

Maybe so, but is your using EL84 amps really helpful when the discussion is about ice modules?

Don't mean to be difficult, but as Nuck said above I guess folks just have to hear the different offerings and come to their own conclusions.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 594
Registered: Jul-07
The point was,ID, generalizing all ICE technology amps together is about as pointless as generalizing about all EL84 amps, or EL34, or KT88, or Class A/B, etc, etc. or any other commonality for that matter. They don't all sound the same or work the same because of one piece of technology they share in common. Do all HDCD players sound the same ? All Gaincard amps ?

That's all. I wasn't talking about my amp at all.

Let's move on.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 460
Registered: Mar-04
I understood your point Chris I just didn't agree with it. I agree let us move on.

So did you read that white paper I posted above?
What did you think of it?
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2143
Registered: Jun-05
Different Class D amps sound different just like Class A/B amps do.
 

Platinum Member
Username: Nuck

Post Number: 12676
Registered: Dec-04
They tend to sound like the same soulless robotic mechanisms that they are to me.
The Channel Island stuff was better, but still automated feeling to me.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 2689
Registered: Feb-07
Interesting... I was fixated on those for awhile. I have a thing for monoblocks I guess.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2144
Registered: Jun-05
Nuck which Class D amps have you heard?Most Class A/B amps sound souless and lifeless to me thats why i put up with the heat and balk of Class A amps,your better Class D amps sound closer to Class A than Class A/B amps do.I'll take a Nuforce,Bel Canto,or a Spectron before any Class A/B amp like Bryston,Classe,Mark Levinston ect...on another note I love the Parasound JC-1 monoblocks,but i guess its because they run in pure Class A up to 25 watts,and as much as i love those amps I'll take I'll take the Bel Canto Ref 1000's,Nuforce 9SE's,or Spectron Musica over them as a mater of fact,the only amps i would choose over them are all Class A amps from Pass Labs,Puaraux,Plinius,and Clayton again at the very top of those lines which will be 3 to 5 times the Class D amps prices that i named.
 

Gold Member
Username: Artk

Albany, Oregon USA

Post Number: 9998
Registered: Feb-05
I'm with Nuck most of the class D stuff I've heard I could live without forever. Kind of liked the Bel Canto's but again didn't get a chance to run 'em through a large selection of music. Overall I'll take class A/B.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2148
Registered: Jun-05
Art you knew my stance on Class D 3 years ago when Eddie was raving about them,which we both know his beloved Panny was terrible.Me being a big Class A junkie,and even preferring the better Class D amps over some of the Class A heavyweights hey.....they must have improved by leaps and bounds,6 years ago when i 1st heard the $20k Halcro's i hated them,but boy has that technology progressed faster than anything in audio history.When you get a chance spend a lil time with those outstanding Bel Canto's next on my list is getting aqainted with the Spectron,Jeff Rowlands,and Chord Mezzo 140's.
 

Platinum Member
Username: Nuck

Post Number: 12684
Registered: Dec-04
The last I heard were Channel Island D100's, with Joseph speakers.
The Joseph's are never described as lifeless, but the CA amps made them flat, to me.

Which Classe AB amps have you heard, TW?
 

Gold Member
Username: Nickelbut10

Post Number: 2594
Registered: Jun-07
" I'll take a Nuforce,Bel Canto,or a Spectron before any Class A/B amp like Bryston,Classe,Mark Levinston ect"

Oh my good god. Not too many people would agree on that statement TW, but its your ears and your preference so thats cool man. Everyone is different. My dealer and the local dealers here would of falling over dead if they heard someone say that.LOL!!!
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2158
Registered: Jun-05
Nick its many people around the forums that prefer the Class D heavyweights(Bel Canto,Nuforce,Spectron,Jeff Rowlands,Chords) to the heavyweight Class A/B even some heavyweight Class A.I've noticed most of the Class A followers are adopting Class D,so thats saying something in my eyes,im a Class A guy,and im turning over.
 

Platinum Member
Username: Nuck

Post Number: 12691
Registered: Dec-04
The last Classe amp that I had, the ca300 , would eat any D amp for lunch.
You are not going to replace 100lbs of copper with a chip.
I ain't buying it, not in mind, ears or soul.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 461
Registered: Mar-04
How are those X-amps treating you T?

Are they the second gen amps with the new flyback transformer, heat sinks, and other changes?

How would you describe their sound as compared to the other class D amps you have heard?
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2159
Registered: Jun-05
Nuck I've heard the big Omega they had on numerous occations with the B&W 800 sigs,it was very bright to my ears and lean in the midbass.In that same shop same room 1 year earlier the 800 sigs were set up on some Mark Levinston gear,and it was very impressive.I've also heard the whole Delta setup on the B&W 802D,Era D14,and Era D10,i have to admit i really like it,the Delta's had good pace and swing better in those departments that I've ever Classe before,it did lack some richness thru the lower midrange,which would steer me away from it,but it had great clarity without being bright.And over the years I've heard countless Classe setups and they all sounded lifeless and boring and bright,I saw and heard 1st hand how Levnston gear smaked their flagship Omega's,but i liked the Delta gear,not my cup of tea,but i realize its many virtues,but as a collective whole I've never really been impressed with Classe.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2161
Registered: Jun-05
Jesus,the Seymour's are impressive according to the review and their specs and at a very fair price,I want them the big 1's of course,wow!
 

Gold Member
Username: Nickelbut10

Post Number: 2596
Registered: Jun-07
I just can't see myself how the Class D technology could possibly be engineered to sound better than Class A or A/B. But hey thats just me.

Classe gear is widely used in very popular recording studio's. Could the music engineers be getting it all wrong?lol Same would go for Bryston gear. When are the recording studio's going to come to their senses and use NuForce?lol.

Hey to each their own, I am leaving it at that.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 462
Registered: Mar-04
REF1000 MKII Mono Amplifier
Power Output: >1000W into 4 ohms, >500W into 8 ohms
Minimum Load: 2 ohms
Frequency Response: +/-0.5dB 20Hz-20KHz, all loads
THD+N: 0.007% 1W, 1KHz, 4 ohms
IMD (CCIF): 0.0007%, 1W, 14:15KHz, 4 ohms
Output noise: 90uVRMS A-weighted 10Hz-20KHz
Voltage gain: 27dB (single ended or balanced input)
Damping factor: >1000
Output Impedance at 100Hz <8 milliohms
Dynamic Range: 120dB
Input Voltage for Max Output 3Vrms
Input connections: Single-ended RCA or balanced XLR

M2 Direct Digital Amplifier Features
# Direct Digital Amplifier
# 2 X 250W Continuous Power at 8 and 4 Ohms
# >500W IHF Dynamic Power
# <0.004% THD 20Hz -- 20kHz from 500mW to 250W
# >120dB Dynamic Range
# 40uV Residual Noise
# >2000 Damping Factor at 50Hz +0/-0.5dB Frequency Response 20Hz -- 20kHz, -3dB >85kHz
# Channel Separation >90dB @ 1kHz, 80dB @ 10kHz

Price for both is the same (Bel Canto x 2) but the Nad also gives you more:

Analogue-to-Digital Conversion
# A/D Conversion for Analogue Inputs
# Multi-bit Delta/Sigma 24/216kHz
# 0.0004% THD
# Sample rate 32kHz - 192kHz
# 124dB S/N Ratio
# High Resolution 120dB Digital Attenuator

Ins and Outs
# Inputs Digital SPDIF: AES/EBU, Coaxial X 2, Optical X 2
# Inputs Analogue: Balanced, Single Ended
# Processor Loop: SPDIF Optical (Mac PC compatible) out/in
# 2 Sets of Speaker Binding Posts to facilitate Bi-wiring
# Remote Control
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2162
Registered: Jun-05
Yep ID the nad may have a few more features,but i gaurantee The Bel Canto's will eat the Nads for breakfest,lunch,dinner,and desert.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 463
Registered: Mar-04
What is that guarantee based upon?

Certainly not the specs. Did you read the white paper I posted above? I would have thought with your keen interest in class d amplification that it would have garnered some interest. But, I suppose it is Nad and it is just breakfast, brunch and a late night burrito for the class d heavyweights.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2163
Registered: Jun-05
ID,Mine are the 1's thats have all the problems corrected,the 2nd gen hasnt come out yet,but all the problems have been ironed out,but i do think they have the new flyback transformer,mine have been problem free.They remind me of small
Ref 1000's very good bass,dynamics,very good dimensiality and good midrange body,they easily best the SP-3,they actually sound more tubey than it,they have excellent attack and pace,hopefully the new 1's will have balanced outputs.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2164
Registered: Jun-05
For 1 thing its that the Bel Canto's are proven and getting better with each version,Bel Canto didnt stop making tube gear for nothing,an 2nd of all Nad barely makes good Class A/B,comparing the 2 companies over the years,its no contest,Nad is a budget maker enough said.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2165
Registered: Jun-05
Nuck the Ref 1000's will smoke those CA-300's like a cigar,they were some of Classe's i was never impressed with,Classe just has never pushed my buttons beautiful case work and inovative,but boring and vampire like lifeless,its atleast 20 Class A/B makers i would choose over them.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 464
Registered: Mar-04
That doesn't prove anything except your bias.

I have not made any claims, I leave that for you to do.
I do have a suggestion though, since you love to audition and swap out gear (like nobody I have ever seen) why not wait until you hear the M2 before you go off half cocked making claims you cannot back up. I will ask you again, did you read the white paper I posted above and if so what are your interpretations of it?
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 465
Registered: Mar-04
"at least 20 Class A/B makers i would choose over them".

Is Nad one of the 20?
 

Platinum Member
Username: Nuck

Post Number: 12692
Registered: Dec-04
Does it still sound like a NAD?
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 466
Registered: Mar-04
I don't know, I would imagine based upon the different technology it would have little to no sound.
But I leave the blanket statements to the "experts".
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2166
Registered: Jun-05
Humm.....im being no more biased than people on this thread are being about Class D amps,and my claim isnt biased towards Nad,they are a budget company and they always have been,Bel Canto is not and they never have been,thats not a opinion thats just a fact.And yeah your right i do swap out a lot of gear,I have the means to do it to,so you can take it for what its worth and yeah i dont need your suggestion,you go audition the Nad.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 467
Registered: Mar-04
A budget company, what is that? Before you make claims I would think it to be wise to listen first? If that sounds unreasonable, it says more about you than it does me. I am not one of those who have made any claims one way or another. I ask you for the third time have you read the white paper and if so what are your impressions?
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2168
Registered: Jun-05
No Nuck Nad isnt 1 of them,on any day,week,month,year,or millineum.I hope it doesent sound like a Nad,that would mean it would sound like thick slow sonic mush.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 468
Registered: Mar-04
Well then they have one market segment covered and now it is just a matter or marching on to get the rest.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 469
Registered: Mar-04
What exactly are you looking for in audio equipment T? I mean you are never satisfied and you seem to know more about what sounds proper than so many others. Kind of like David Carradine in kung fu, always in search of something. I assume your future travels to the far east will be more productive.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2169
Registered: Jun-05
No i havent read the white papers,but I've seen the specs and from what i saw it was impressive,but it remains to be seen how they sound,but im not really interrested im not paying $5 or $6k for anything with a Nad emblem on it,their current lineup is below par to me,except they have a decent budget preamp thats been the best thing they make for atleast 25 years,their CDP's are ok for the money,their Amps are not very good,its my opinion its just that simple,like i said take it for what its worth,many people on this thread isnt interrested in Class D,im not interrested in Nad,so like i said earlier you go listen to it,if you feel that says something about me and not you,so be it.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2170
Registered: Jun-05
My quest is fine ID I love trying new stuff,and if somethings in my system thats isnt right to me it gets changed,you can never know enough in this hobby,I enjoy what i do,you on the otherhand seem like you dont have fun,I hope you do in the future besides thats what this hobby is for ID,enjoy.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 470
Registered: Mar-04
but im not really interrested im not paying $5 or $6k for anything with a Nad emblem on it.

Wow, ok that was very illuminating. So despite it's performance and feature set it is the badge on the box that matters, how highbrow of you. Yet you have budget priced av123 speakers. Let me guess they are the best thing since the swans and the last brand you were doing back flips over. Why not read the white papers since you are interested in audio. What is the harm in doing so, you might learn something T?


"its my opinion its just that simple,like i said take it for what its worth".

I take it for what it is, an (often uninformed) opinion.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 471
Registered: Mar-04
"I enjoy what i do,you on the otherhand seem like you dont have fun"

On the contrary T, I get a great deal of enjoyment in listening to music and perusing the audio forums.
T. what are your opinions concerning the white paper?
Since it is barely mid-fi it should not take you much time to get through it and pick it apart. I am awaiting your impressions on the class D M2.
 

Gold Member
Username: Nickelbut10

Post Number: 2598
Registered: Jun-07
Tawaun- are you not the one always on this site pushing budget gear as being 'killers'. Yes a company like NAD produce good sounding gear for cheap. Making them a budget hi fi company. What happens when a company like Rega or NAD start making 6 grand amps, with a whole different design and built in a total different warehouse with better QC. Is that amp still a budget amp? A lot of people, from what I read, sell their Bel Canto Monoblock's because they are so fatiguing they want to make people rip their ears off their head. Thats ok though because they are not a " Budget Company". So what happens when hi end companies make crap that is over priced and based on a full marketing strategy? Thats ok because Tawaun claims its Hi-End. Just like your AV123 online speakers would blow away Art's Rega's. Just like Bel Canto blow away Classe and Bryston, two companies that have the majority of the worlds recording studio market. But hey, Tawaun thinks Bel Canto is better. Your a moron. I think you confuse your crappy opinion with reality. Nobody here is ripping other brands. People on here actually own some of those brands. You think ID, sean, and Mort like hearing you rip the brand they just recently purchased while your on another thread helping them buy your " budget" "killer" 300 dollar speaker? It is ok to have your opinion. But its your opinion so choose your words wisely. Hey, I bet a NAD M2 would beat the pants off Bel Canto giving certain speakers and associated equipment. So what is better then? " Better " ? You come across as being more ignorant at times, than helpful. I'll let this thread be now, and let you continue to tell everyone what gear is better than what, and which gear sucks. All mighty audio god. Moron.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2171
Registered: Jun-05
Look here ID,enough about me what do you have?so i can give my unbiased opinion on your rig.I've already talked about the Swans and av123,yeah the X-statics are somewhat special,im not the only 1 that thinks so either.Be honest ID i see you coming at me,would you pay $5k or $6k for the new Nad? im sure many people wont either,so would that mean they being biased to?Do you own Nad? So just because i feel there are better Class D offerings thats already been proving themselves with the technology and stopped making tubes to make Class D,im wrong for not being interrested in the Nad,that as a company thru reliabilty problems,not sounding as good as they did in 80's,and their so-called highend series the M series isnt very good either and im wrong for that?
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 472
Registered: Mar-04
The white papers Tawaun, for the love of all that is holy did you READ THE WHITE PAPERS? If not then why not, you seem intellectually curious?
 

Gold Member
Username: Nickelbut10

Post Number: 2599
Registered: Jun-07
It isn't very good to you, or to everyone? The technology is there to be good in their Masters Series. Its right there. Open one up, its well built, and has the same Technology and Power as any. It may suck to you, but not to others. Your opinion.

Classe, bright and sucks you say. To who? Class is widely used by engineers and producers in many recording studios around the country. Bryston amps own 60 percent of all recording studios in North America. Oh, but it sucks. Tawaun said so. Rega? sucks. Tawaun said so. Classe? Sucks, Tawaun said so. AV123? Amazing, best thing out there. Tawaun said so. Beta 20;s? Best speaker under a grand, Tawaun said so. Giant killers are the best, but Budget gear sucks. Tawaun said so. AV123 T525 or what they are called smoke Rega R5's, because Tawaun said so. People, you don't need an opinion. Tawaun has his, and thats what makes our hobby go around. Tawaun's crappy opinion. Moron.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2172
Registered: Jun-05
Nick its good that you have the internet behind you to call people names,but i wonder what kind of guy you would be if you didnt have it like in person,i bet you would be quite as mouse,hey Little Nicky im not that kind of guy,im pretty physical as a matter of fact you need to watch who you call a moron,choose your words wisely,I like traveling you never know i might be in a town near you.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 473
Registered: Mar-04
Now Tawaun, why does it always come down to this with you? I have seen this display on your part many times. Now if you are around my way I would be happy to host you but not in the state you are in right now! Let me tell you this, nobody does barely mid-fi like unbridled. But it comes with a pricetag, you buy the beer and I don't want any of the macro crapola, Sam Adams T, all the way. Now you have to admit you do have a flair for the dramatic don't you? Look, why don't you click on the link I posted above (those pesky white papers) and take a few deep breaths and calm down. A good read will clear your mind and it will occur to you that non-verbal means of addressing a disagreement are wrong.
 

Gold Member
Username: Nickelbut10

Post Number: 2600
Registered: Jun-07
I'm a lover not a fighter. I don't like getting hit in the face because it is pretty. I am just the kind of guy that would burn down a guys house while his family slept in it. *Twitch* *twitch*
 

Gold Member
Username: Nickelbut10

Post Number: 2601
Registered: Jun-07
Forget that last post, it was a joke Tawaun. I don't need to take this too too personal. My face is pretty though, I wasn;t joking about that.LOL.

The moral of the story is everyone has their opinions, just make sure everyone knows its one man's opinion and not a fact.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2173
Registered: Jun-05
Hey Nick i like fire to weapons of all types,what i stated above im serious,your not a fighter where im from lovers dont call fighters names,they love im actually both and im quite fluent in both and very pretty as well,and being millatary i fly all over the country and out of country i can always stop in your town and audition some audio gear and see you.Now you can stop with the names,or it can go to level your not ready for,i spend alot of time and money on this hobby I share what i know I'd rather keep it like that,dont ever threaten my family,your diggin a hole with your tongue.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 474
Registered: Mar-04
Tawaun I though you were taking my advice and doing the breathing while reading the white papers?
Before you go special sauces on us, just remember what you posted above "I enjoy what i do, besides thats what this hobby is for ID,enjoy".
Ok, when you talk black ops I don't see how that intersects with even below mid-fi audio.
Just relax, perhaps you should let the lover side of your personality take hold. Pop in some Barry White and let the x-statics with their open baffle design let the image float around you.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2174
Registered: Jun-05
Ok,thats fine but i dont like being called names,i know I am rather absolute a lot times but there are more facts to this hobby than most people are willing to except,nobody wants there stuff to be inferior to another guys especially priced the same or cheaper,their are products that are clearly superior and their are gian killers example the X-static and the X-mono's and there's plenty of others,now someone believing that is another matter
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 475
Registered: Mar-04
Well said Nick, I totally agree. Let us conserve our energy and move forward in a calm a reasoned manner. Opinions are like ______, we all have one. Conserving energy is in the spirit of class D amplification. By the way did I mention that the M2 is 90% efficient? That level of efficiency would make even "crazy" al-gore happy. I sense a kumbaya moment on the horizon.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2175
Registered: Jun-05
Ok ID im calm the Nad is very impressive 90 efficeincey mind bogling but it didnt say where like Seymour said 83% at 50hz,Dampning factor >2000 on par with the rest of the Class D amps the digital processing may be the most impressive I've ever seen in a 2 channel product 250watts at 4 ohms and 8 ohms not so impressive reminds me of the T-amps not doubling up into 4 ohms Bel Canto,Spectron,Jeff Rowland,Wyred for Sound,Seymour has considerable more power and the Nuforce more in 4 ohms,its a intergrated amp not so impressive,I would like to pick my own preamp since it is the most important part of the chain,mono have better channel seperation and way less crosstalk.It may actually be worth $5 or $6k because of the because of the processing im not really clear on the efficiencey 90% at 100hz,200hz,knowone knows they didnt specify its processing in particluar is very impressive to say the least,the Nad has plenty of potential,spec wise its their most impressive accomplishment ever i give it the thumbs up.
 

Gold Member
Username: Nickelbut10

Post Number: 2602
Registered: Jun-07
Who are black ops?

The twitch thing was a joke TW. Chill. I am in good shape but by no means a fighter. I am 5'11 , 165 pounds. Ball player. Never had to be physical in my lifetime as I had close friends and family like : Brother, 6'5 240, now a black belt. Friends : Dan, All canadian rugby player 6'7, 320. Derek - 6'2 240, all Canadian boxer. And many others who usually took care of things for me. Am I a wimp? probably. But have at least 8 guys on my side that could seriously hurt a lot of people. And did so for many years through High School and college. That and I am the senior engineer for the largest Security distributor in Ontario, Canada. I know, and talk, and deal with the local police force on a weekly basis, and they know me by first name, first beer basis. Does this all make me tough? Nope. Don't care either. You can beat me all you want, dont care. I have always been the guy that said what was on his mind, to anyone about anything. This is not about who has bigger balls, but I will stand up and be the bigger man and apologize to you TW for the name calling. I will take your statement about you being rather Absolute as such as well. I understand. The whole upper level of this post, is stupid, talking about who is tough and who knows who. Dumb. I have sloped down to a low level today. Anyway, lets forget it, and talk about audio. Class D tech still has my attention. I am still doing research on it, and would love to hear more of it before I come to any of my own conclusions. Cheers.
 

Gold Member
Username: Nickelbut10

Post Number: 2603
Registered: Jun-07
90 percent? Wah. Leave it on at all times without jacking my hyrdo bill?lol That is impressive. In a green world that is nice.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 595
Registered: Jul-07
ID, I know you are consumed with someone reading that freakin' whitepaper and offering you their opinion. I'm not sure why, but you sure seem obsessed with it. Just so you know, it's a marketing document. It has a bunch of fancy marketing words, and pretty graphs. Nobody is going to be able to read that and tell you if that amp will sound good. It may sound great, it may not. Go listen to the amp and tell us how it sounds compared to something else you've heard. That, I would be interested in. I read that blessed whitepaper and as with probably 90% of us it's mostly interesting but I don't know enough about electrical engineering to know how that translates into good sound. As a matter of fact, even the designer has to listen to it to find that out. What do you want someone to tell you about that whitepaper ? Anyone who was going to offer you an opinion on that would have done it by now. Move on.

I know you like NAD gear, that's cool. Power to ya. But you don't seem willing to talk about any other brand mentioned hear, other than to dismiss it. Why is that ?

TW, you are as opinionated as any person I've ever seen (or in this case read). I have no doubt you are passionate about this hobby which is wonderful. You may not know this, or be aware of it, but you belittle people, their gear, and their choices. If people get their backs up it's because you do not allow for alternate points of view. Guess how many people enjoy that ? And if your answer to someone calling you on it is to suggest violence then I feel very sorry for you.

Let people have their views and allow that they enjoy their choices, and that their choices make them happy. Allow that, as they allow you to do the same. If ID likes his NAD equipment, that's great. It's good gear. If you don't like it, just don't comment on it, or say "it's not my cup of tea"....that's fine. But don't slam someones gear. Would you walk into someones house and say 'man, I wouldn't own that amp, it's crap!". I would hope that you wouldn't. So why type it here ?

A little respect please.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 476
Registered: Mar-04
"Who are black ops"? Not who but what...

"Black ops missions often fall into the deniable category, a situation in which there is no claim of responsibility for the action, and/or a false flag operation is used to give the appearance that another actor was responsible, or -- most often -- black operations involve extensive arrangements so as to be able to hide the fact that the black operation ever occurred. Black military operations, or paramilitary operations, can be used by various secret services to achieve or attempt to achieve an unusually sensitive goal. The methods used in black operations are also used in unconventional warfare".

Anyway back to class D...
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2176
Registered: Jun-05
Good deal Nick you got a lot in your corner.lol

On a better note the Nad is impressive,but you gotta admit it comes up short in the motor department,the brain is very smart,not being mono's is another thing.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 477
Registered: Mar-04
Chris you don't sound like you took much out of it.
You don't understand what they are saying and that is ok but don't dismiss it based on your lack of understanding.

"I know you like NAD gear, that's cool. Power to ya. But you don't seem willing to talk about any other brand mentioned hear, other than to dismiss it. Why is that "?

It is rude to put words into someones mouth Chris. I have not dismissed any gear don't go and make things up.

Now we can move on or stay here the choice is yours. Tawaun, Nick and I have made the choice to move forward.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2177
Registered: Jun-05
Hey Chris me and Nick just ironed out our problems and he brought a few things to light to me,im rather absolute and i dont mean to belittle peoples gear,I'll work on that so you can chill with the preaching and analyzing like you have a PHD in physcology which you may very well have,and your quite oppionated yourself,but its like this, i dont need you as my doctor nor would i choose you no offense but it is what it is.........now back to Class D.....
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 478
Registered: Mar-04
"On a better note the Nad is impressive,but you gotta admit it comes up short in the motor department,the brain is very smart,not being mono's is another thing".

Sorry T I couldn't resist.

ADVANCED POWER SUPPLIES
The M2 uses three power supplies, all of them highly efficient switch mode types. Each channel gets its own high current power supply in a dual mono configuration. The Input stage and control sections get their own dedicated supply with multiple regulated secondary voltages for individual sections.

I look forward to what people say about the unit when it comes out at the end of the summer. I took an interest in the unit in part based on NAD's collaboration with zetex. That is what differentiates it from all the other class D offerings.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2178
Registered: Jun-05
ID what do you make of the Nads power compared to the competition?
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 479
Registered: Mar-04
One thing about Nad amps is they never double the wattage when the impedance is halved, it is just a design philosophy. I would imagine that 250 watts per side in addition to Nad's well known dynamic capabilities would be adequate for the majority of setups. But for those who crave/require more power the M2 simply will not suffice and then we have to move on to other options such as the bel cantos etc etc.

 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2179
Registered: Jun-05
I didnt see the amprage listed,do you know what it is? the seem to be between 40 and 50 peak currents thats always been a important aspect to me it usually goes hand in hand with the dampning factor.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 480
Registered: Mar-04
I also like the other features it offers, very nice. But since they are the first to implement the technology the cost to the consumer will be high. There are plans on implementing the technology in a 7 channel a/v receiver, imagine the M2's power specs in a 7 channel a/v amp! In time as with all new technologies it will trickle down to the classic series. I just picked up the c275 awhile back and think it is pretty nice.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2180
Registered: Jun-05
Nad has always had very good dynamic peaks in miliseconds,so i dont expect anything less out of this unit.I've always like their preamp its a nice litte piece at a fair price and it has a very good MM/MC phono stage.
 

Gold Member
Username: Nickelbut10

Post Number: 2604
Registered: Jun-07
Yup, men can be men, and get hot collared. But the real men are the ones that make up, shake hands, and move on. Like TW and I have. Beers and Cubans on me. I just filled the Humidor today. mmMMMmm Cigars....

I don't want to sound like a NAD preacher here, but I want to just add their new stuff is much much better, so I wouldn't expect anything less of their class D stuff as an improvement in sound over their last offerings. There is a lot of gear out there that I prefer over NAD, but at least they are getting better finally. NAD really looked like they were dragging a dull plow behind them the last few years dealing with QC crap, and falling behind in technology. It appears that whoever has been making their masters series is now making the classic series. Which is good.

Which pre amp are you talking about TW? The 162 or the new 165? I liked my C272 when I had it, it doesn't compare to the 3B IMO but I wouldn't expect it to coming in at the time at 800 dollars.

Could the class D technology in their AVR's allow for that Modulated technology still?
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 481
Registered: Mar-04
Well, modular design is something that Nad is committed to so that will stay. I can only assume that like most switch mode amps the new Nads will devote less space to heat sinks and large torroidal power supplies which makes the modular design concept easier to implement?
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2181
Registered: Jun-05
The 162 my dad just bought 1 at a pawnshop for a $150,im thinking about few different pre's I dont know which 1 to go with.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 596
Registered: Jul-07
"Chris you don't sound like you took much out of it.
You don't understand what they are saying and that is ok but don't dismiss it based on your lack of understanding. "


"It is rude to put words into someones mouth Chris."

Yes it is, so don't. I didn't dismiss it. I told you what I took away from it. Not good enough ? You think I should have taken away more ? Sorry to disappoint. I clearly don't have your insight into such highly technical documents. Never mind me. I'll just go blow dry my hair.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 482
Registered: Mar-04
"I told you what I took away from it".

Yes and based on your lack of understanding you
dismissed it.

"Sorry to disappoint".

Don't be sorry I have come to expect it.

"Never mind me. I'll just go blow dry my hair".

Carry on.
 

Gold Member
Username: Nickelbut10

Post Number: 2605
Registered: Jun-07
I always thought the 162 is a great little amp for the price TW. 150 dollars? wowsers, good find.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 597
Registered: Jul-07
Yes and based on your lack of understanding you
dismissed it. "


You'll have to help me. How did I dismiss it ? I believe that's your perception, which you're extrapolating from something that I can't quite find in what I typed. And you didn't dismiss the Seymours ? I think you're putting words in my mouth for which you've already chastised me. You have an issue with me, for some reason. You can carry on taking shots at me if you like, I really don't care. But I will defend myself. My preference is for you to give me the same respect you would want for yourself. But it's your choice.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 483
Registered: Mar-04
"Just so you know, it's a marketing document. It has a bunch of fancy marketing words, and pretty graphs".

Your tone and tenor is dismissive. If you don't care to read it that is fine, I am not "selling" the M2 to anyone. I am not putting words in your mouth Chris, I simply respond to your statements. I don't have an "issue" with you. Do you really think I am involved on an emotional level? If holding you accountable for what you say is tantamount to "taking shots" then you live in a strange world indeed. I was not dismissive of the Seymours at all, if you want to scroll up and find where I was please do so. I did comment on the use of ice modules by several manufacturers which is a fact not an opinion. Chris, you catch more flies with honey than vinegar.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2182
Registered: Jun-05
Yeah like you disrespected me,today and the other day,Chris go blow dry your hair again hope you got some good shampoo for those flakes......ID carry on with the Class D.......
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2183
Registered: Jun-05
Yep Nick its in new condition the only thing he has to do is order the remote from Nad,it didnt come with 1,but $150 i would have bought it without a wince of hessitation myself even if i didnt need a preamp.
 

Platinum Member
Username: Nuck

Post Number: 12693
Registered: Dec-04
remotes.com
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2185
Registered: Jun-05
Yeah Nad will probably charge him about a 125 bucks,275 aint bad for the arguably the best budget preamp of all time,that unit has a lonnnnngggg......history about 30 years with consistent improvements over the years with each updated version,I gotta give Nad credit for that.
 

Silver Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 598
Registered: Jul-07
"Your tone and tenor is dismissive."

Your perception of my tone and tenor. Typed words don't have either. You continue to read things into my words that aren't there. You asked for an opinion (repeatedly) and then when you got one you didn't like it and got snotty (and still are). Your issue which you are still trying to stick on me. Nope. Hold yourself accountable.

"Yeah like you disrespected me,today and the other day"

Pot, meet kettle. That's rich TW.
 

Gold Member
Username: Nickelbut10

Post Number: 2607
Registered: Jun-07
TW- A universal should work. What kind of remote is it? The HTR-2? I would have bought it at that price as well, no matter what. I wonder how good the new 165 is. That Chris fellow from Just Hi Fi said that when they replaced the 162/272 combo with new 165/275 combo on the exact same setup they all went " woooohhh, everything is tighter, more detailed, better. Right away". He was saying within seconds they knew it was better. Thats saying something. I would credit the 275 amp for that as it is highly improved. Looks like a Masters Series inside. Comes in at almost double the price of the 272 though.

Anyway, what are some cheap class D products out there? Not willing to spend NuForce prices yet, until the technology is out there for a while and until I can hear it more. Do some of the cheaper brands have any similarities to the more expensive stuff at all?
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 484
Registered: Mar-04
"Your perception of my tone and tenor".

Which was accurate by the way.

"You asked for an opinion (repeatedly)"

I should have asked for a "useful" opinion. I have to spell things out for some.

"then when you got one you didn't like it and got snotty (and still are)".

Wrong Chris, it is not a matter of like or dislike, I expect those types of responses from you (short on substance). Snotty you say, come on Chris don't be so thin skinned it's a rough way to go through life.

"hold yourself accountable"

Actually Chris I asked you to do so by showing where I was dismissive of Seymour amps. Keep looking Chris and get back to me on that one.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2188
Registered: Jun-05
Hey Chris here's the kettle and the pot,we're talking about Class.....D,what are you talking about?
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2189
Registered: Jun-05
Chris the X-mono's for $149 a peice original price was $299 a piece,they outperform my Purers Class A amp section at what Class A does better than anything,and kills the Bada in the bass.av123 had a lot trouble out of these and they didnt quite measure power wise for their goal which was 175 watts conservativelly a block,instead their about 150 still probably conservative,but all the bugs were ironed out,just so happens knowone realy knows because of the trouble Mark got into with LS6 &LS9,and sub amps.The new version will be out soon the'll be 200 or more watts totally bug free at the $299 price as originally stated.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13685
Registered: May-04
.

"totally bug free"


Well, that's reassuring.



I assume the manufacturer said that.





.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2192
Registered: Jun-05
I heard it from the horses mouth Jan in person,mine havent given me any trouble,but if they did or do they would go back in a hurry.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2193
Registered: Jun-05
The Seymours are on my Short list they are half the price of the Bel Canto's Ref 1000mkII,Nuforce 9SE,Jeff Rowlands,Nad M2,and the Red Dragon Laviathan's and every bit as speced out and from what i read just what im looking for and they have world class build quality with tru beauty aesteticlly.The Wyred For Sound SX-1000's are $1199 a peice,thats another option so are the Channel Islands although im with Nuck no these they dont do anything wrong but dont do anything special either,although according to the reviews the SX-10000 are to the cool side of nuetral not really my cup of tea,if av123's new X-mono's have balanced outputs it wil be hard to ignore them for 299 a peice,especially knowing how good the old 1's sound the Flying Mole mono's are another option on the cheap,so is the Pop Pulse T-150 and the Little Dot 150.
 

Bronze Member
Username: Ezntn

TN

Post Number: 17
Registered: Apr-09
Perception

Will be auditioning Nuforce MCH 2C5 within a week or so, along with the AVP 17 to replace my Rotel
This is Class D technology based on their Reference V2 SE

Perception ... all in the ears, and mind
Planning on mine being open to the new equipment
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2194
Registered: Jun-05
Have fun Bryan,you'll love what Nuforce can do in the bass,I've never heard any amps match them there.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 485
Registered: Mar-04
Hey T, didn't MLS give those who own the v.1 of the x-amp the option of trading it in for the v.2? I remember hearing something about that and if that is the case and you get full value for the trade will you do the swap? I think what happened with the v.1 is that the factory he contracted the amp to did a piss poor job and that is a shame. Hopefully (it is said to be the case) all corrections have been made at the new factory. AV123 had a rough 2008 but they are good people and I wish them well.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2195
Registered: Jun-05
Yep ID he did give that option,for me it wont be a problem i can always take them up to the shop and compare them.Yeah the factory screwed up things royally,all the corrections were made,they have about 40 version 1's left at $149 its a rediculous steal,their doing good now like i said I've never seen that many stocks of speakers,their getting the subs with the new amps by the truckload,and nearly all the LS6 &LS9's orders are filled,once their all fillled the thought of being able to buy the LS6's is certainly on my mind,thats why the Seymours are on my mind 1000 watts a side on them monsters whew......
 

Silver Member
Username: Magfan

USA

Post Number: 436
Registered: Oct-07
Class 'd' efficiency numbers are usually listed only for output stage and than at high power....where it shows best.
Nad doesn't seem to double up into 4ohms? why, is I suspect some kind of corporate decision. That there dynamic power is very in-line is terrific. Unless you listen to sine waves or reruns of The Outer Limits, hi RMS values are a non-starter.
I wonder just how much current a speaker could handle. I suspect 'hi current' is a red herring number.
As for remotes, try the LogiTech? very large database of supported equipment...I even found a CA listing that works for my 840c.

My PSAudio ICE based GCC250 run MUCH cooler at any loudness than the Direct TV receiver in the rack space above it. The DTV unit is listed as drawing about 20 watts.
 

Silver Member
Username: Unbridled_id

ChicagoUsa

Post Number: 486
Registered: Mar-04
Does the rise of class D and other forms of amplification mean the class a a/b are going the way of the Dodo?
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2196
Registered: Jun-05
Thanks leo,that was very imformative,ID I doubt it right now,with all the Class D doubters around its gonna take a while,look at this thread for instance.But you look at companies who have changed,Bel Canto and Jeff Rowlands,both of these comapanies made tubes,thats quite a 390 degree flip,when tube guys make that kind of change that really means something.
 

Platinum Member
Username: Artk

Albany, Oregon USA

Post Number: 10037
Registered: Feb-05
I've listened to the Bel Canto amps and thought they sounded pretty good if a bit polite. I 've not heard the Rowland but have heard nothing but bad things about it. Perhaps in a few years when they get this thing down I'll make the transition...keep in mind that I have nothing fundamentally against class D or any other technology...if sounds good I'm all for it.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13686
Registered: May-04
.

Jeff Rowland never built tube based equipment for commercial release. He has stated he admires tubes for what they do well and has dabbled in tubes for his own education early on in his education. But his Rowland Design Labs products have always been firmly placed in the solid state world. What makes Jeff's products so appealing to many listeners is his ability to bring voltage controlled and current controlled technology closer together while largely avoiding the problematic issues of either device.



.
 

Gold Member
Username: T_bomb25

Dayton, Ohio United States

Post Number: 2198
Registered: Jun-05
Lots of people say the Bel Canto's are polite,I dont think so,but its been said a lot,maybe the mkII version adress's that Art.
 

Gold Member
Username: Frank_abela

Berkshire UK

Post Number: 3675
Registered: Sep-04
Tawaun,

Sorry I missed this thread (well, not really, I hate spats).

I have heard the Bel Cantos on several occasions and found nothing interesting there. Polite is one word I guess, but generally I find them bland, with no dynamic range and generally very very boring.

We have had all the NuForce amps in the shop for our critical listening (we were given the option to represent them). We found them polite, detailed, clean sounding and boring. Oh they were powerful of course, but still not much point when there was no soul to the music. We chose not to represent them of course.

Chord is not class D. Chord uses switched mode power supplies into class A/B.

I have heard nothing but good stuff about Jeff Rowland. I had not realised those amps had gone over to class D.

I would love to find a class D amplifier that satisfies me. I just haven't yet, and that includes the Arcam class G in the old P1000, but I haven't heard the new AVR600 enough to see if it qualifies yet.

The only ones I have heard that struck a chord with me have been the class T modules in Naim's n-Vi (pretty good if not earth shattering) and the class D Chapter Audio.
On the NAD power reporting issue. I thought NAD had adopted a general power rating approach where they simply guaranteed the power rating at a value. in other words they don't supply figures for different loads as far as I know. They established this practice about 3 years ago IIRC.

Traditionally class D amplifiers suffer when attempting to drive changing loads and especially low impedance loads. Has this trait been resolved? I ask because that was defniitely an issue with some of our speakers.

Frank.
 

Silver Member
Username: Magfan

USA

Post Number: 441
Registered: Oct-07
Id, some time ago you listed the specs for the BelCano Ref1000 amp.
Now, don't get me wrong, but some of the specs are 'misleading' at the very least.
First and foremost people look at the power output.
In the case of the Ref1000 it is 500 watts, for sure, but only for 15 seconds. NOT RMS in the FTC sense or definition.
My ASP500 based amp (the P means it has onboard powersupply) is rated at 550 into 4 ohms at 0.1 THD at 1KHz. a typical way to rate this parameter. This drops to 'only' 300 watts at 8 ohms, same conditions.
Problem is, the amp will only do 500 watts for 60 seconds with NO preheating. I guess that means from stone cold. Refrigerated in a 0 humidity room will get you an extra 15 seconds before meltdown.
FTC power is 200watts at 4ohms, but only to 3KHz, due to a meltdown of the Zoebel Network used to remove the HF switching component from the output. OOOPS! The spec mentions 'no external heatsink' which implies better performance if bolted to some nice fins.
And, if that weren't enough, the efficiency is 'only' 83% max, at 200watts / 8ohms, falling to 81% at 500watts / 4ohms.

The good news in this, to me, at least is that music is not FTC / RMS. Even getting a little loud into my lo-sensitivity panels, I can barely warm it. I suspect, but will take some actual measures soon as I make a pigtail cord, that the dynamic range will be quite dramatic. I suspect this amp'll kick along at 125 watts with 500 watt peaks for quite a while. I have no idea how much power it will take to pop the 4amp fuse in my panels.

And for Frank, from the 'for what its worth' department, the ICE modules are rated down to 2 ohms.
Also, due to the Zoebel Network, there is some phase shift associated with higher fruquencies, say above 15 to 18KHz, which may interact badly with some reactive speaker loads. Lower impedance loads in this case make it worse.

None of the above matters if you don't like the sound. But be aware that many manufs use unmodified ICE modules. Others do unspecified mods while still others advertise extensive recapping, additional mechanical damping and premium internal wiring. And, in the case of ICE based integrateds, an additional gain stage before the amp. All can change the character of the basic module. for good or bad?
 

Gold Member
Username: Frank_abela

Berkshire UK

Post Number: 3706
Registered: Sep-04
Leo,

Thanks for that. Yes, indeed, different class D amps do have different signatures, although all the ones I've heard seem to be a variation on the clean but clinical theme at the moment. The only one I heard that was clean but still engaging was the Chapter Audio, admittedly in quite peculiar circumstances (hifi show).

I am particularly impressed with the efficiency ratings. It was my understanding that under load the efficiency of these amps dropped quite significantly (I read an article somewhere to this effect - must have been wrong). As for the high frequency phase shift, this is undesirable but not necessarily a killer since the high frequencies usually imply lower power requirements anyway (so not stressing the amp too much provided the phase shift is at least sensible (i.e. less than 45 degrees).
 

Silver Member
Username: Magfan

USA

Post Number: 442
Registered: Oct-07
Frank,
2 things. The ICEpower website as the complete specs for the modules. The ones without powersupplies have efficiencies for output stage ONLY listed while the 'P' modules are wall plug to speaker ratings.
I will also be posting my rant on phase angle. Hint:
Look up Power Factor on the internet. This closes the loop for me on something Ecoustics 'Star' poster said many times and was a source of great curiosity to me.
more later...............
 

Silver Member
Username: Magfan

USA

Post Number: 443
Registered: Oct-07
Here is a true technical article, from the folks who supply Axiom there amplifier modules:

http://www.irf.com/product-info/audio/classdtutorial.pdf

This is part 1 of a 2 parter, and all good real information.
 

Gold Member
Username: Frank_abela

Berkshire UK

Post Number: 3714
Registered: Sep-04
Hehe, yes, phase angle. My Mani-2s have a 45 degree phase angle in the midrange IIRC! Makes them an absolute b4st4rd to drive. Not sure how this affects class D amps but will read the article...
 

Platinum Member
Username: Nuck

Post Number: 12928
Registered: Dec-04
Not bl00dy easy, Frank!
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13745
Registered: May-04
.

"Phase angle" affects all amplifiers in the same fashion. This is due to the effect of either capacitive or inductive "reactance". In either case the voltage and current are out of phase with each other, one leading and one lagging.

When no reactance is present, say, with only a resistor* in the signal path, the voltage and current pass simultaneously through the circuit and work is accomplished. Once a capacitor or inductor is inserted into the signal path the two components of electrical "work" - voltage and current - are thrown out of phase. A capacitor always results in a 90° phase shift in one direction - voltage lagging current. An inductor results in a phase angle with a similar amount of phase shift - 90° though with the opposite properties in regards to voltage and current.

When the current and voltage are shifted by 90° it is considered a state where "no work gets done". Therefore what you are talking about with electrical phase angle due to the capacitive or inductive reactance of a passive speaker crossover is how much work can be accomplished when the phase angle drifts from 0°. Less work accomplished means the amplifier must work harder to produce the same results as the angle approaches 90°.

When a reactive load shifts the electrical phase angle as the impedance drops at the same frequency, more current is drawn through the speaker circuit but less work is accomplished. When you view the electrical phase angle of a speaker system in measurements such as Stereophile takes you will see a "+" and a "-" going direction to the measurement. There is no consistent direction for capacitive or inductive phase angle when various labs take their measurements other than one measurement techinque should produce consistent results. Normally capacitive results will be shown as "-" going and inductive phase angle will be shown as "+".

This "lack of work being done" is what makes speakers with high values of electrical phase shift difficult to drive.


http://www.ibiblio.org/kuphaldt/electricCircuits/AC/AC_4.html

http://www.electricianeducation.com/theory/capacitive_reactance.htm

http://www.symphonysound.com/articles/tubefriendly.html

http://stereophile.com/reference/707heavy/

http://stereophile.com/features/99/

http://stereophile.com/features/100/

http://stereophile.com/features/103/


*Most resistors have some amount of inductance and therefore cannot make a perfectly accurate circuit when considering electrical phase shift. Inductors have resistance and capacitors have inductance and the whole thing is not as simple as it appears. All of these effects shift values when heated by work being done.


.
 

Silver Member
Username: Magfan

USA

Post Number: 447
Registered: Oct-07
Well, I wanted to save this for later, but please check out this link to 'Smith Charts'. this is a very good and easy way (once you get used to it) to view the relationship between phase angle, frequency and impedance.
http://www.hometheaterhifi.com/component/content/article/228.html

It is usually considered to be OK for there to be larger phase angles where there is less musical energy, usually higher frequencies. Where a large phase angle occurs at the same frequency as an impedance low, that is where problems occur.

The question I have yet to answer for myself is one of amplifier testing. I haven't seen an amp test into real (simulated) speaker loads. So, 2 amps which are similar into a resistor may measure very differently into such a load. I have seen schematics of such loads but haven't yet seen any comparison data between amplifiers.
I would hope that 'better' amps also measure better when subjected to heavily reactive loads.
 

Silver Member
Username: Magfan

USA

Post Number: 448
Registered: Oct-07
Jan, what got me started on this was 1st your frequent comment that speaker designers and amp designers don't talk. Huge phase angles and running an amp's output devices out of there SOR was the first thing.
Than, I purchased a 'Kill-a-Watt' plug in power meter. I'll be posting a review, shortly, since I think it should be part of the kit. One measure of this 20$ 'toy' is that of Power Factor. As I paged thru the screens of the Kill-a-watt, I noted that the VA and watts were related as a function of Power Factor. it is simple multiplication. At least for your house, you get BILLED for watts and consume VA. The power company basically supplies more power than you pay for, as your phase angle increases. The company I work for pays a premium based on a power factor below the threshold set by the power company, usually from 0.9 to 0.95, the lower being less desirable. Power Factor correction is possible, even on an industrial scale, for a price. It is possible to convert Power Factor BACK to degrees with a hand calculator with trig functions. PF 0 =90degrees.

Anyway, thats what got me started down this line.
My original goal was to try to convince people that impedance was NOT the be-all, end-all of a 'bad load' and that phase angle was more an issue.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13746
Registered: May-04
.

The Smith's Chart looks very much like the impedance/phase angle graphs that appeared in Audio magazine in the last years of their existence, a pig tail shaped plot. Which is easier to interpret for the average reader, the Smith's Chart or the style presented in Stereophile, is debatable IMO.



If you'll read the Stereophile article on loudspeaker testing, I believe you'lll find a description of their simulated loudspeaker load. Otherwise you're quite right about reactive loads and the use of an almost purely resistive load as a test device has long been one of the points of contention when subjectivist and objectivist audiophiles debate over amplifier sound vs measurements.



"I would hope that 'better' amps also measure better when subjected to heavily reactive loads."

Yes and no in that regard. Much depends on what you consider "better" and what you consider to be acceptable measurements. One problem seems to exist, that is that most of the high end's most difficult to drive loudspeakers are not well suited to a voltage source amplifier - which encompasses about 99.9% of all designs. This is the crux of Nelson' Pass' current (no pun intended) thinking; http://search.yahoo.com/search?ei=UTF-8&fr=slv8-hptb5&p=Nelson+pass+current+sour ce+amplifier&SpellState=n-2901017669_q-Ez2lG2QWkRv0FK.hCJNCUwAAAA%40%40&fr2=sp-q rw-corr-top

Of course, I am of the opinion that the present crop (as they have existed for the last 25 years) of current hungry audiophile speakers is taking the hobby in the wrong direction.


"My original goal was to try to convince people that impedance was NOT the be-all, end-all of a 'bad load' and that phase angle was more an issue."


It is the combination of impedance and phase angle that constitute the real world speaker load an amplifier must face. However, the audiophile speaker designer has been in love with a low impedance speaker load for decades despite its tendency to make for less than stellar stability in the partnering. While well designed and executed solid state, direct coupled amplifiers have minimal frequency response problems with wandering impedance loads, amplifiers with a high-ish output impedance will sound quite "unflat" with respect to frequency response when low impedance loads are present.

The class D & T amplifiers have tended toward problems with both high and low impedance loads since the outputs of the amplifier are almost always meant to drive a simple, straightforward 8 Ohm load. Potential frequency response errors make correct speaker matching of primary concern with the high efficiency amplifiers, even more so IMO than with most transformer coupled tube amplifiers. If you haven't taken to a class D amplifier, possibly you haven't heard it when paired with the right loudspeaker.


.
 

Silver Member
Username: Magfan

USA

Post Number: 449
Registered: Oct-07
Jan, to get back to 'd' amps!
They all have some kind of filter to remove the switching 'noise' and therefore ARE very....prone...to hf rolloff. Just look at the provided info by the ICE folks. The 1kw module made famous by the BelCanto 1000 series monoblocs is nearly 1db down at just over 20khz...and with the resultant phase shift. My 500asp PSAudio integrated is much better off in this regard. All the 'd' amps I have seen detailed specs for are NOT rated in the FTC version of RMS power, however. My amp is full power, for about 60 seconds. Either the output devices fail or maybe the filter (zoebel) will simply melt down.
Even my IRAudio project amp out in the garage has the same issue. Also, the efficiency is always rated at full tilt and much lower at lesser outputs. At a couple watts, they aren't much if any more efficient than a good A/B design.

My 'd' based amp seems fairly happy with my panels, which while 'current hungry' are certainly NOT a bad load within the definitions on which we agree, with the possible exception of lowish sensitivity. Placement / setup is critical and still a work in progress. I am trying to get the spouse to agree to some diffusion in the listening area. I spotted an 8'x10' deep pile Persian today which would look fine on the back wall, but got no traction.

I am just tired of people saying that a speaker is a bad load simply because of impedance which lingers at 4ohms, or may drop to 3 or so. This, if it were pure resistive would present NO problem to any but the cheesiest amp. Combined with phase difficulties is the killer.

The DISadvantage to the Smith Chart, which since I am a techno nerd-type have NO problem reading is that there are NO frequency markers. As it turns out, however, each 'way' of a speaker will have a curly q associated with the x-over point. I mentioned these in a post several years ago and nobody responded. I persisted and eventually found them again. The article I linked is a very clear explanation. I'd like some raw data to plot and some software. I don't think Excel will hack it!!!

Two other notes::
Tube stuff apparently doesn't like one type of reactive load...and I simply don't 'member if it is to the capacitive or inductive side. I will provide a citation for this if requested but it'll be a pain to find again.
I will also be posting a mini-review of the kill-a-watt. This little bugger is quite a bit of fun. I still need to construct a short pigtail so I can connect it without having to tear my stereo out from the wall to plug in. What a pain. I would like to provide some baseline numbers. For example, and not a good one, a 4' fluorescent tube when cold draws about .34amps, 40VA and 32 watts for a power factor of 0.8 Here in SoCal, my line voltage is a tick over 117 right now; the lowest value I have recorded is right at 115, during the heat of the day.
Also, big fans (induction motor) have a very low PF until spinning. They also have pretty large current draw while running up.

To clarify one minor point. When I say that I hope better amps measure better, I of course mean into real-world loads. An amp as 'power station' to the speaker is limited by physical laws to a relationship between phase angle and actual delivered power. This sets an upper limit. I think that poor amps won't even do this and will crap-out at the first sign of a weird load.

Jan, this pretty much closes the loop for me on the comment which started me down this path, that being that 'speaker and amp designers don't talk'.... Indeed, it would appear they share very little but a taste for cheap cigars and oxygen usage. I think we are up against the 'wall of physics'.
It's a beautiful nite out tonite, Not a cloud in the sky and Jupiter off in the SouthEast is almost bright enough to read by (slight exaggeration)
 

Platinum Member
Username: Nuck

Post Number: 12935
Registered: Dec-04
Nice post Leo.
 

Platinum Member
Username: Nuck

Post Number: 12936
Registered: Dec-04
I wish I had a day to spare here in L.A. to drop by.
Next time, I will save a day!
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13747
Registered: May-04
.

"They all have some kind of filter to remove the switching 'noise' and therefore ARE very....prone...to hf rolloff. Just look at the provided info by the ICE folks. The 1kw module made famous by the BelCanto 1000 series monoblocs is nearly 1db down at just over 20khz...and with the resultant phase shift. My 500asp PSAudio integrated is much better off in this regard. All the 'd' amps I have seen detailed specs for are NOT rated in the FTC version of RMS power, however. My amp is full power, for about 60 seconds. Either the output devices fail or maybe the filter (zoebel) will simply melt down."


Switching noise can come from the power supply which is often a switch mode type. Replace the switch mode ps and the noise becomes less of an issue. How much this bothers any one listener is debatable. Not to sound too much like someone who believes my ears tell me everything I need to know, but a reliance on measurements can have more value for a debate over specs than over real world sound quality. If I measured every piece of audio before I listened, there would have been far fewer pieces of equipment to hear.

The hf rolloff is IMO not all that significant. That's not to say there aren't excellent reasons to want extended hf response beyond 100kHz, but believing specs tell me everything I need to know has not been in my mindset for a long time. Pulling simple numbers out of any group of measurements will all too often lead you down a blind alley when it comes to sound quality. Unless, that is, you are a "measurements tell us everything" type, then you believe what you believe and I believe what I believe.

My understanding of the problems class D amplifiers face when tested under the FTC power spec has to do with the pre heating requirement for amplifiers. Apparently class D amplifiers do not fair all that well under those conditions. Besides, the FTC specs you mention were established decades ago when manufacturers of cheap-crap were stating bizarre, over-inflated "music power" and IHF wattage numbers for cheap class AB amplifiers. RMS output had nothing to do with the stated wattage of a Magnavox console. So the FTC stepped in with an attempt to make amplifiers less confusing for the average consumer.

We can see how well that worked out by looking at the wattage specs of most mass market HT receivers.

Those FTC numbers drove the horsepower race of the mid '70's and gave us wonderful products such as the Pioneer SX-1010 receiver.

As stated the FTC regulated RMS spec still has no bearing on your desired real world speaker load or reproducing music. But it made a great marketing tool once the manufacturers figured out how to get around the requirements.

(Here's a description of the Stereophile simulated speaker load; http://www.stereophile.com/reference/60/)

Class D & T are still fairly young technologies that haven't had much attention paid to them by very good engineers or those designers who tend to think outside the constrictions of traditional design. My crystal ball tends to see class D as having potential that will come to the fore in the next decade or so as more designers exploit more performance from the technology. However, since audio moves slowly away from certain aspects of familiarity it will probably require more than a few excellent designs to break class D out of being more than a niche product. How many male audipohiles with testosterone driven speaker towers and garden hose style cables want a great sounding amplifier they can fit in their pocket?



Ix-nay on the ug-ray, leo. You want diffusion on that back wall (the one behind your listening chair, right?).


"I am just tired of people saying that a speaker is a bad load simply because of impedance which lingers at 4ohms, or may drop to 3 or so. This, if it were pure resistive would present NO problem to any but the cheesiest amp. Combined with phase difficulties is the killer."


Of course, the problem here is there are no purely resistive speaker loads. There are better designs than the audiophile market presently labors with but purely resistive is not on the horizon. If the impedance were made rather stable over a broad region of frequencies, there wouldn't be as much of a problem for most amplifiers, even if that impedance is fairly low. If transformer/autoformer coupling were more common, there wouldn't be as much of a problem. That is not how most of today's audiophile systems are designed. Once again speaker designers aren't communicating with amplifier designers and even the handful of audio companies that produce both products seem to follow convention more than common sense - or history.


Transformer coupled tube amplifiers generally are not fond of capacitve loads - but then what amplifier is? The transformer represents a coil (inductor) so you can see why following that with a highly capacitve load would be undesireable. With that said one of the magical combinations has always been the original Quad electrostatic panels with their highly capacitive loading and the Quad tube amplifiers of Peter Walker design. But they were designed as a pair with "current dumping" (1950's style) being the goal of the amplifier. Just an example of what you can achieve when you think like a speaker and amplifier designer and pay little attention to the trends and fads of audio.


"I think that poor amps won't even do this and will crap-out at the first sign of a weird load."


Well, ... yeah. That's the point.


"I think we are up against the 'wall of physics'."

We are but even more so we are up against the wall of marketing BS. Or at least that's my opinion of the audiophile world in general.



.
 

Silver Member
Username: Magfan

USA

Post Number: 450
Registered: Oct-07
No time for a detailed reply. But, I sort of liked my Pioneer SX727 receiver. Sent it back at least 3x to get an FM drift off frequency fixed. It would just SNAP off of center and that was that. Seemed to be heat related, but the darn thing wasn't in any enclosure and wasn't stacked, either.

I think worse than any mythical -.5db at 20khz is the same phase shift problem CD players, especially early ones were up against. And, while the SMPS noise can make it downstream, the 'sampling' that goes on with 'd' stuff is also a problem, with the 400khz sampling. I saw a 10khz square wave scope picture with 10 or 11 bumps on top of each square wave....a result of sampling.
I am on record and have said for quite a while that specs are at best 'advisory', a position I see no reason to change or modify. Specs are fine, and in some cases give bragging rights or whatever floats your boat, but in the long run you've got to listen to it. That my 'd' amp won't pass FTC muster for the 1hr / 1/3power preconditioning period is of little interest to anyone except those who listen to sine waves and test tones. Even the Krell integrated got so hot you couldn't touch it. In my test session with that amp and some Magnepan 3.6 panels, it Really cooked. In my stereo enclosure, it would last maybe a couple months, and certainly NOT survive a summer!

To restate what you said, Jan, Audio is a very conservative (hobby, avocation, sport, compulsion) and new technologies are adapted slowly. I would love to see what someone of the Nelson Pass calibre does from a clean sheet of paper with an original 'd' design.

The rug (proposed) was for the far back wall of the listening area...side opposite the speakers which are in a short wall setup. Currently, there is a very small tapestry there, about 37"x44" made from wool and hung 2" from the wall. When the first stereo went in this room, the echo from this wall was intolerable and this was the interim.....20 years ago, cure. The room itself has 8 sides, is totally asymetric and has a vault ceiling of nearly 12' at the peak. The only bass problem I have detected is in my den where there seems to be a big bass bump / bloated bass caused by some (helmholtz related?) effect.

And, from the for what it's worth / wonder department....
Is it possible to make a pure resistive transducer? Could a transducer be designed with built in PF correction to keep the PF as close to unity as possible?

If I may go WAY off topic here, the whole world is smoke and mirrors, from our beloved politicans to our business leaders and sports heros.
A smart friend of mine once said that 'reality was everything that didn't go away when you quit believing in it.' Well, just quit believing the BS and see what shakes out!!
regards......
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13748
Registered: May-04
.

"I think worse than any mythical -.5db at 20khz is the same phase shift problem CD players, especially early ones were up against. And, while the SMPS noise can make it downstream, the 'sampling' that goes on with 'd' stuff is also a problem, with the 400khz sampling. I saw a 10khz square wave scope picture with 10 or 11 bumps on top of each square wave....a result of sampling."


Sampling? There is no "sampling" in a class D amplifier. It is an analog amplifier.


.
 

Silver Member
Username: Magfan

USA

Post Number: 453
Registered: Oct-07
From the Axiom article. The same information from the IR paper is less accessible.

Basically, a digital (Class D) amplifier takes an incoming analog signal and converts it into a digital representation comprised of pulse widths. Although there are a number of different design variations, Class D amplifiers are essentially switching amplifiers or Pulse Width Modulator (PWM) designs. The incoming analog audio signal is used to modulate a very high frequency Pulse-Width Modulated (PWM) carrier that works the output stage either fully on or off. Later on, this ultra-high-frequency carrier must be removed from the audio output with a reconstruction filter so that no ultra-high frequency switching components remain to corrupt the audio signals.

This signal, at about 400khz or even higher is what must be 'removed' from the output. I'll try to find the scope picture from the amp test.
 

Silver Member
Username: Magfan

USA

Post Number: 454
Registered: Oct-07
From the Stereophile test of the BelCanto integrated::
The amplifier's output impedance, measured at the speaker jacks, was 0.2 ohm at low and middle frequencies, dropping to 0.04 ohm at 20kHz. The Bel Canto's frequency response was flat within the audioband, but its top-octave behavior depended on the load impedance (fig.1), presumably due to the interaction between the load and the amplifier's low-pass output filter. (Amplifiers with a switching or class-D output stage produce a high level of ultrasonic noise that needs to be reduced if it is not to be reradiated by the speaker cables.)

This is a reference to the frequency to be removed by low-pass filter.

Also from the Stereophile test::For all the remaining amplifier tests, I used an Audio Precision AUX-0025 Switching Amplifier Measurement Filter between the test load and the test systems. This is because, even with its own low-pass filter, a switching amplifier still puts out a high level of ultrasonic noise that, without further filtering, will drive the input of the test system into slew-rate limiting. For example, without passing an audio signal, the Bel Canto S300iu put out 1.2V RMS of ultrasonic noise with a center frequency of approximately 350kHz.

For the complete measurement panel from the test quoted above::
http://stereophile.com/integratedamps/bel_canto_eone_s300iu_integrated_amplifier /index4.html

Sorry for the misuse of 'sampling'!! my bad.
However, the non-SMPS related switching noise in 'd' amps IS an issue, as virtually ALL real measurement / testing uses some kind of HF output filter to make sure that the switching junk goes away.

2 other things, though:
Jan, can you make any relevant comments about my listening room....you said before that it sounded as if I needed more diffusion for my panels.
Also, without regard to specsmanship and other nutty test/measure stuff, I still really like the 'd' amp I have. Really clean, and without any of the stridency that the previous Rotel RB-1070 seemed to have at high levels where in comparison the Rotel 'ran out of breath' while providing much low end detail, when listening at 0-dark thirty in a dead quiet house with the VC at the very lowest fifth of its travel.
 

Silver Member
Username: Magfan

USA

Post Number: 455
Registered: Oct-07
Jan, a complete aside, and you certainly don't have to answer unless you see fit,
In some recent history reading, I note that Francois-Rene` de Chateaubriand, on any short list of great writers of his time, was married to one Celeste Buisson de La Vigne!!!
Any relation? Are you related to that French Family.
Sorry if I'm being rude, but your name is unusual to say the least..........as if I have any room to talk!
 

Silver Member
Username: Magfan

USA

Post Number: 456
Registered: Oct-07
AH! Found it!
Please see link below, figure #2 for 'switching' noise in a 'd' output. This is from a Hypex UCD module, NOT a B&O ICE module. Same difference.

http://stereophile.com/solidpoweramps/805cia/index4.html
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13749
Registered: May-04
.

"Basically, a digital (Class D) amplifier takes an incoming analog signal and converts it into a digital representation comprised of pulse widths."

I saw the references to "digital" in the article and hesitated to post it for just that reason. Many people mistakenly assume the "D" in class D is meant for "digital" when it merely follows along the lines of class A, AB, C and so on. While there are a few amplifiers that operate in the digital domain for most of their signal path (Meridian being the most prominent), all ampliifers at this time need an analog output stage to drive a conventional speaker.

Class D does not operate in the digital domain at any time as there are no ADC's involved in the input stages of any class D amplifier I am aware of. The confusion seems to come from the switching that occurs in a class D amplifier and the apparent similarity to the 1's and 0's that make up a digital bit stream. The two could not, in most people's assessment, be more different from one another.

The switching that occurs in a class D amplifier is an "on/off" function which you could loosely describe as the same action that occurs within the digital signal. However, there is no representation of the signal contained in the "on" position of a class D gain stage as there is in a digital switch. The signal in class D is still represented by voltage flow just as it is in any other analog gain stage - again that lends itself to misinterpretation of how switching operates but the signal is strictly in the analog domain in a class D gain stage. There is no interpolation of what the "on" means as to frequency, there is no conversion from analog to digital and then back to analog occurring in a Class D gain stage and to my knowledge there can be no aliasing noise in a class D gain stage as it exists in a digital domain processing stage. Class D has no use for Nyquist theory.


In a vastlly oversimplified concept, a class D gain stage is operating very much like an ultra-high speed class AB stage would, switching on and off to gain efficiency in its operation. As I said, the switch mode power supply (if used) introduces switching noise into the signal path, class D is after all still modualting the power supply to make an output voltage just as class A. AB, B and C would do. And the constant switching on and off of the gain stage does lend itself to noise but that noise can be filtered out of the signal path fairly easily since it occurs at such high frequencies - certainly compared to our common conception of "digital" which has a high frequency limit of 22-24kHz.

The effectiveness of the filter coils (inductors) at reducing this nose, however, is compromised by the size of the package, class D favoring extremely compact signal traces and boasting small size as one of its virtues. But, still, it is the radiated noise from the gain stage that has seemed to hold back most class D designs and therefore limiting their use to car stereos and subwoofer amplifiers.

Hopefully with designers such as PS Audio and Bel Canto making strides in its applications class D can find more flavors to offer and more adherents to its advantages. We'll see what happens next.

.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13750
Registered: May-04
.

"Sorry for the misuse of 'sampling'!! my bad.
However, the non-SMPS related switching noise in 'd' amps IS an issue, as virtually ALL real measurement / testing uses some kind of HF output filter to make sure that the switching junk goes away."



"Please see link below, figure #2 for 'switching' noise in a 'd' output. This is from a Hypex UCD module, NOT a B&O ICE module. Same difference.

http://stereophile.com/solidpoweramps/805cia/index4.html"




True, testing equipment is bothered by the switching noise of a class D product due to the proximity of the equipment being tested to the test gear itself and the unfortunate use of interconnecting cables as a necessary evil - "Wes Phillips mentioned at the start of this review that I dislike measuring amplifiers with a class-D output stage. This is because such designs can throw out enough ultrasonic noise that you can never be quite sure that what you're actually measuring is the input stage of your analyzer being driven into slew-rate limiting. (For more on this subject, see the measurements sidebar accompanying Michael Fremer's review in April of the class-D Yamaha MX-D1.) What I do, therefore, is to insert, when appropriate, a sixth-order low-pass filter set to 20kHz or 30kHz between the output of the amplifier and the analyzer."


But, we're talking about test gear being the problem here. So interpolatiing that bit of evidence into what we are actually hearing would appear to be two distinct issues. Class D components offer a particular challenge to the user, of that there is no doubt. In other ways the same could be said for many more traditional components. CD and DVD players can radiate noise into analog circuits. Some listeners claim to "hear" LED's. Users are advised to power down any digital sources when not in use to avoid such noise contamination. That hasn't stopped digital sources from flourishing in the market.

As I see it, if a class D component doesn't do what you want as far as music reproduction and it has been considered appropriate for the system - particularly speaker loading - then you should pass on that component. I would give the same advice regarding any class A or AB component or any tube, solid state or FET based component. IMO this "radiated noise" issue is of use more to the partisans in the audio community than to the average audiphile who is mostly interested in obtaining the best sound quality possible for (typically) the least amount of money spent.

If the noise truly bothers you, then don't buy the component. If you are being told the noise should bother you and you heed that advice without a fair audition, then you are committing one of the first sins of high end audio.



.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13751
Registered: May-04
.

"Jan, can you make any relevant comments about my listening room....you said before that it sounded as if I needed more diffusion for my panels."


I probably can't help much over the forum. As I remember your room has some peculiarities that make set up difficult. Trial and error with a clear, logical path in your head is normally the best route in such cases. A notebook to jot down results doesn't hurt.

I tend to dislike absorption as a cure all. And most absorption falls into either the category of too selective in its effect or too broadband to my ears. That might seem a contradiction but either way I hear too many unintended consequences of absorption.

More than a few rooms I've encountered, mine included when I switched from a monopole to a dipole, tend toward a dead sound due to too much absorption. IMO you can hardly overdo diffusion if you have any amount of common sense about you. The overall sense of life in the room is maintained while the issues of reflections are minimized. I would advise some absorption in corners where bass problems lurk and at any very early reflection points such as a floor that cannot be successfully treated with diffusion but otherwise my current thinking is to minimize absorption techniques and regain the ambience that was put into the recordings. I would highly recommend this approach to anyone using a speaker that operates in any other manner than a strict monopole.

My exception to this would be placing absorption very close in to the speakers, even on the front baffle itself. Using absortption at the speaker's edges serves to focus the sound away from the sidewalls which solves the problems of early reflections to a large extent. It varies from speaker to speaker as to its effectiveness and isn't always advisable on dipole panels but, if it works visually in your room, then I would give it a try. Otherwise, tend toward more diffusion and less absorption.

http://www.tubetrap.com/tube-trap-setup.htm


"Also, without regard to specsmanship and other nutty test/measure stuff, I still really like the 'd' amp I have. Really clean, and without any of the stridency that the previous Rotel RB-1070 seemed to have at high levels where in comparison the Rotel 'ran out of breath' while providing much low end detail, when listening at 0-dark thirty in a dead quiet house with the VC at the very lowest fifth of its travel."


I've not heard a class D amp running Magneplanars. On a purely technical basis, if the amp has sufficient "grunt" to take on the rather inefficient manner of the panels and their ribbon type tweeters, I would think they would match quite well. The normal issue of the Magneplanars for most amplifiers is their rising inductive load at the high frequencies. A class D amp needs inductive filtering to sound its best. Seems like the two should work well together IMO.


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Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13752
Registered: May-04
.

My name comes from Northern Italy. My ancestors sold the estate in the late 1800's and made the trip across the ocean with the intent to land (probably) in California. How they ended up where they did is a story which involves a moving train and money kept too loosely in a coat pocket.

The family estate was at the foot of the Alps in the Peidmont region of Italy, close to a small town named Susa, http://images.search.yahoo.com/search/images?_adv_prop=image&fr=slv8-hptb5&va=su sa+italy&sz=all.

I normally respond to questions about my name and it's origins by suggesting the Italians did speak to the French but it was quite often at the time we were invading France.


If you know the history of Italy, France and Italy become more entwined in each other's cultures during the time of Queen Catherine of d'Medici in the 16th century, long before there was a unified "Italy". She brought many Italian cooks with her when she married into the French Royalty and names and menus travelled easily across the border. Some of my family spells the name with an "e" on the end and some with an "a" though the "e" is less prevalent in Italy itself.

You probably know the word "vigna" can be translated either as "wine maker" or as "vineyard" depending on its use in a sentence and the dialect being spoken. I always assumed my ancestors were either the area's wine makers or the town drunks. My family records do not go back far enough to tell the difference.


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Silver Member
Username: Jazzman71

Phoenix, AZ USA

Post Number: 790
Registered: Dec-07
Interesting post, Jan. Great wine comes from that region, so whether they were making it or drinking it, it was probably good. I doubt the family name would be associated with notorious drinking, however. Probably just spent a lot of time in the tasting room.
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