What does 192khz/24 bit DAC mean to amp's performance?

 

Anonymous
Sorry for asking such a basic question, but I wanted to get a honest answer and not marketing jargon. Also my DVD player outputs signal in 96khz/24 bit format. What does all these boil down to?
thanks
 

While it may be a simple question to ask, the answer is far more difficult to both get at and grasp than many might think.

The short answer is that, practically and appreciably, there is no difference.

At first glance one might think, "hey, DVD-A in 2 channel stereo IS 192/24." but don't forget that DVD-A leaves your player as analog *only*...which means that having 192/24 DACS in your receiver doesn't do squat. It's the DVD/CD player's DACs that are doing the conversion in DVD-Audio.

Unless your receiver is able to "up-sample" (not just resample or interpolate) the actual bitstream (Denon starting with the 3808 can do this I think) the usefulness of 192khz DACs on a receiver are nill.

However, the biggest enemy of digital signal conversion is jitter (timing variations in the delivery of bits between transport and DAC) and NOT the sample rate of the converter. Additionally, each piece of electronics that has a DAC also has its own clock. Each clock will invariably introduce timing variation which lead to digital artifacts--which lead to compromised sound (I am speaking in the extreme now).

In fact, even in the land of the audiophiles, where CD players usually consist of separate transports and DACs, the latest thinking (and field tests) prove that the best design (given total isolation) is to have the DAC *inside* the same box as the transport (connected via a very high speed bus) to minimize the jitter inherent in another piece of electronics (this relates to power supply issues).

If you're intent on boring the hell out of yourself...here are two really good articles on the subject:

http://www.soundstage.com/earmarked/earmarked200106.htm

http://www.soundstage.com/yfiles/yfiles200011.htm

Happy reading!

-h1pst3r
 

Phil Krewer
I really don't know if the 3803 upsamples or not. I know that some of the Onkyos have this feature, but in stereo mode only if I remember right.

H1,

I didn't read the articles so I may be full of sh1t, but when I had the 797 with upsampling I really didn't see much of a difference. But someone else ears may be better than mine. I'm sure the jitter problem is real and measureable, but I wonder if we would really notice an audible difference. It somewhat reminds me of the debate between optical and coax digital cables. The optical cable has more places to fail (lose bits, etc) and theorectically would contribute more to the jitter problem because it requires an extra stage in "decoding". So, many people favor coax, but I honestly can't tell the difference.

Which brings me to my point. That is there a many things in audio that a difference can be measured on hightech equip that most of us can't hear. Sometimes, myself included, we get caught up in "theoretical" difference and let them influence what we buy. When in "truth" it won't make an impact to our ears. From that stand point I'm going to ignor the jitter problem and let my ears decide and use the DACs that sound the best.

Cheers,

Phil
 

Anonymous
HI

I am going to buy dvd player with 192/24 DAC ,my reciver is 96/24 dac.
Is it true that if I conect by optical cable dvd players 192/24 does not matter ?
 

Phil,

I definitely agree with you about "theory-hype" and I try to stay away from it...actually I find many articles on such subjects useless to us mere mortals.

The reason I posted those specific articles (the first one maily) is that the assessment was done with *ears* and not gear.

The reviewer goes to lengths to relay the *actual* perceptible differences in 44.1, 96, and 176khz (yes 176, not 192). It is a very interesting read and states essentially, with the engineer who designed the DAC in question, that jitter (or the ability to reduce it) has a larger impact--or at least the same impact--(in terms of hearng a difference) as the DACs sampling rate. Overall the best difference, when a difference was perceptible, was increased "space" or ambiance...makes sense given an increase (theoretical doubling) in frequency range.

The fact that the article got down to what we can *hear* is what I found most interesting.

Cheers,

-h1pst3r
 

Phil Krewer
Hey H1,

I read the first article and while the guys writing style was abit to be desired I managed to force myself through it. I came away with a litte different impression than you did. The engineer felt it was due to reduction of jitter but I really didn't see anything that proved this and the author really wasn't sure himself.

First of all the DAC was still off board as you would find in a receiver. Only the upsampling card was in the Marantz. Now he said this was put in the Marantz because of jitter, but the only way to really show that it made a difference is to place the card in the DAC.

Second, the improvement in sound quality may have more to do with how it was upsampled than where the DAC or upsampler was located. What I mean is that upsampling in mutiples of 44.1 maybe the reason the sound was improved over 24/96 and probably over 24/192 if the cd was upsampled to that rate. DVD audio is already at that rate and didn't utilize the upsampler card, but did utilize an off board DAC. It makes me wonder if 24/88.2 would be better than 24/96

Third, to get any inhancement of sound quality there would have to be a difference with just upsampling by itself otherwise there would be no difference than with playing a cd at 16/44.1 and 24/176.4. Maybe that's the case, but the article didn't make that clear to me except for his remark that he didn't notice a difference between that and 24/96. Again there may have been a difference if it were 24/88.2.

Now, the real difference may have been with the difference in transmission speed of the digital signal, but he only mentions this briefly. In that case the only thing that would be needed would be installing a network card in the Marantz. I really couldn't say this for sure from the article.

Of course, I'm pretty clueless about this stuff and I'm sure some of my assumptions are wrong. If there was something I missed please let me know, but other than using multiples of the original source and possibly the transmission speed of the signal. I don't see what this set up would have done to reduce jitter.

Take care,

Phil
 

Phil,

Well said and the point about transmission speed seemed to be the only *valid* point that I came away with as well.

I agree that the author was more enamored with his own writing style than with conveying point with concision.

I guess I was lumping errors associated with timing (slower transmission speeds and the timing errors that accumulate) into what I was calling (and considering) jitter.

You can see how paraphrasing that article was kind of a pain.

Thanks for the comments!

-h1pst3r
 

Karthik
Thanks h1pst3r for answering my original post. Looks like i have bitten off more than i can chew by asking the question :) I went thru both the links although I couldn't quite follow the content in the first one. Anyway, so what i understand (correct me if iam wrong) is that unless my receiver (yamaha 5590) can upsample the 96khz digital audio out from my DVD player, its pretty much usless. So I either go for a 192 khz DVD player or 96khz receiver (yamaha 5560?)
thanks
 

Really,

Phil's take is a healthy one to look at when trying to decipher all the "theoretical" possibilities that are presented with digital manipulation of sound..."can you hear it?"

If the point of your intial question was whether to get the 5560 or 5590 (both excellent units by the way) I would go with the 5560 for two simple reasons:

1. you save some cash...and who doesn't like cash, and

2. the 5590 actually *doesn't* offer preamp outputs where the 5560 does.

That actually made no sense to me when I was really, really close to getting the 5590. The preamp outs offer you the possibility of connecting external amps at a later date if you choose to do that. That would allow you to use the Yam as a preamp/processor (which is does quite well given all its DSP functions), if you ever desire more power.

Anyway, as you can see the khz/sampling rate issue is a wacky, and I think, mostly useless issue for most of us who simply want sonic performance that almost all of us would agree is excellent.

Glad we could (kind of sort of) help,

-h1pst3r
 

Karthik
Thanks h1. well when i started the post, i wasn't even considering the 5560. Only wanted to understand how and whether the sampling frequency made a difference to the amp performance.

The sales rep and the product adverts online, gave me the general impression that higher the sampling rate, the more accurate is the conversion. The following taken from yamaha site

"The HTR-5590's vitally important digital-to-analog converters use an extremely high performance 192kHz/24-bit operation type. They perform accurate sound field reproduction for high quality multichannel sources, and for two-channel stereo, provide outstanding separation and precise musical delineation."

What I couldn't understand is (and u answered it in ur first reply) how does this matter when the CDs and DVDs are recorded at a rate lower than 96 khz. The SACD are higher, but its ur DVDs that perform the DAC conversion in that case as the inputs to the receiver are analog. The sales reps were clueless what i was talking about. And i had never heard about upsampling and oversampling.

So I assumed that a 192 khz was a useless feature, but since iam not very knowledgeable about audio equipment, wanted a confirmation.

Anyway hope this answers the other guy who has a 192khz DVD player and a 96khz amp. If the receiver bypasses (no DSP processing) the 5/6 channel analog inputs (like the yamahas do), then the receiver sampling rate being 96 khz should not matter. Is this right ?(h1 or phil)

Thanks
 

Phil Krewer
Karthik,

First, if your considering the HTR-5590 then I would consider going with the RX-V1300 instead. The 1300 is the same as the 5590 except it has pre-outs and a 12 volt trigger. Both units retail for the same price.

My take on the 192/24 DACs in a reciever are about the same as yours unless upsampling comes into the picture. That being said if it were my money and all things else being equal I would get the 192/24 DACS. Just in the sense that its more "future proof".

The DVD questions. If you use the red/white analog inputs from the DVD then you would use the DACs of the DVD player, but when it came to DTS and DD you would lose all the 5.1/6.1 channel info. If you're playing a SACD or DVD-A then you'll have to use the analog mode, in which case you are using the players DACs.

If you have a player like H1's which has a 6 channel output then you can hook this up to your receiver and not lose the 5.1, but you would still lose any DTS-ES and possibly DD-EX info. In this case you would using the DACs from the DVD player.

If you hooked the player up using the digital output then you don't lose any 5.1/6.1 info, but you are bypassing the DACs on the DVD player and using the DACs on the reciever.

Cheers,

PHil
 

Anonymous
Hey H1,

Question 4 ya, You mentioned the Yamaha 5560 as probably a better buy for the money. On the yamaha website the 5590 is described as having the ability to decode DTS-ES. But on the crutchfield site it only describes the 5590 as having the ability to decode DTS-ES and the 5560 as only being able to decode DDEX. In fact, the closeup shots of the 5560 do NOT show any DTS-ES logo only regular 5.1 DTS however the 5590 does. So do you know what the deal is there? Does the 5560 decode DTS-ES discreetly or not.

thanks
 

Couple of things to Phil and Anon:

PHIL:

your take on 192khz/24bit DACs, is the same as mine AND it was defintely part of my purchase criteria. I wanted them, even if I couldn't immediately use them I wanted 192khz so that I could be somewhat future-proof. This was also my thinking for 7.1 pre and speaker outputs, even though nothing is encoded in such formats yet. If you're going to drop that kind of money why *not* get the benefits of being forward-looking.

As for the conections from the DVD player, my opinion is exactly the same: RCA analog into receiver from DVD player is using the DVD's DAC, 5.1/6.1 (dvd-a, sacd) analog out from the DVD player is using the DVD's DACs, coax or optical digital is using the receiver's DACs.

With my yam 6480, I have all three connected to different inputs on my receiver. The DVD-A 6.1 analog outputs connect to what HK calls "6-ch DVD direct" which I use, obvoiusly for DVD-a. I also use the RCA-analog stereo output (red and white) to connect to "CD" on the HK, this gives me pure analog mode and allows me to use the DVD players DACs on regular CDs. I then also connect digitally via optical to the reciever for DVD movies (DD-EX, DTS-ES) and in order to use the HK's DAC's for audio CD's (great for comparison between the HK's decoders and the Burr-browns on the DVD player). (btw, I prefer the burr-browns ;-)

But, I can also use the on-board DTS/DD decoder in the DVD and connect via the 6.1 output to the receiver if I wanted to use the yam decoders for movies...I generally don't though.

ANON:

From what I see on Crutchfield the 5590 WILL do both ES and EX, where the 5560 will only do DD-EX but not DTS-ES. You only get straight DTS in the lower model.

So, the question, if you're ordering from Crutchfield is, "does DTS-ES warrant an additional $280?" That's up to you, but for the additional money you do get 30 more watts per channel, and many other "goodies" in the 5590. If you're buying from Best buy or better yet Circuit city, you could probably haggle that differnce in half and laugh all the way out to the car.

That was part of the reason I didn't get the 5590...it had all the additional features I wanted above the 5560 BUT lacked the pre-outs. At the time I didn't know what Phil had pointed out in a earlier post...that the 1300 does have the preouts for the same price.

However, I wouldn't be suprised if one of the 5560's additional sound fields *would* replace DTS-ES...they're pretty good...and I know you can apply Yamaha DSP on top of DD and DTS...kinda cool. Having said all that about EX/ES which was absolutely on my criteria list, I now use 5.1...as we say in Boston, whateva!

Good luck,

-h1pst3r
 

Karthik
Hey Phil & H1

I too agree with you both on the connections and thats how I have connected the receiver & DVD player. But only i don't know what future use can 192 khz DAC can have. I know it doesn't hurt to have it if one can afford it. But am curious all the same.

Any new technologies on the horizon? As far as i know, the DVD-A & SACD will not be output in digital format in near future & the the 6 channel DVD audio is going to be 96 khz (due to physical storage capaity of the DVD disc) as per my knowledge. Although I did hear some thing about blue laser DVD technology that could increase the storage capacity of a DVD.

Anon,

I haven't tried 5560, but i initially bought home 5550 which decodes DTS-EX, but uses virtual 6th rear center channel to output it. So wonder why wouldn't 5560 include it.
 

Anonymous
I totally agree, if youre gonna drop that much money on an amp (were talkin "real world" people here, not Joe Millionaire) it is a good idea to try and get something "future friendly". Taking that into consideration, the 5590 or 1300 would be a better buy.

What I dont get with the Yamaha line is why on earth would they make two separate lines (RXV and HTR) when they are pretty much the same thing. If the 5590 and the 1300 are pretty much the same retail price and the 1300 offers pre-outs then why would any one in their right mind take the 5590 over the 1300? Is there any significant difference or reason why Yam has done this that anyone knows of? To me it just makes the line more confusing.
 

Anon

You answered your question with my answer...Sony's blu-Ray may be the next big media encoding technology to allow, among other things, higher sample rates. Blu-Ray will hold up to 23 gigabytes of data, or five times as much data as existing DVDs--enough for two hours of high-definition programming (though likely not at full HD bandwidth).

I didn't know that about the 5550 and the 5560...soemtimes I wonder what Yamaha is smoking when it comes to product differentiators.

-h1pst3r
 

Sorry, previous post was for Karthik.

Anon,

I agree Yamaha is nutty. But really it has to do with retail outlet branding and alignment. They sell their gear (the same units as you mention) at both BestBuy and Tweeter.

The folks who shop at Tweeter like to know that they're getting something ever so *slightly* different (maybe better) than the folks who shop at BestBuy (no offense to anyone).

The 1300 is sold at Tweeter where more folks would be interested in the pre-outs than the average Bestbuy shopper (again no offense).

Think of it as a *very* thinly veiled version of Toyota rebranding essentially the same automotive technology as a Lexus...we like our brands and the recognition they convey. Yamaha has taken a very simplistic (and probably intentionally convoluted) approach to brand-outlet recognition.

-h1pst3r
 

Karthik
Another thing is that yamaha won't allow RX series to be sold online. So you would almost always have to pay retail for it. The only reason I was looking at 5590s & 5550s was that one could get them for bargain prices from authorized dealers. I would have considered Denon3803 or HK525, but again I would have to pay close to 1000 USD while my budget is around 500 USD.

The 5590 not having pre-outs bothered me, but at my budget the only other option i considered was denon 1803, but the 192khz tipped me towards 5590 at that time.
 

Phil Krewer
The only thing I'd like to add to this is that if I'm not mistaken the 5550 doesn't do DD-EX. The matrixed virtual rear speaker can be done with any 5.1 source. I'm not sure what that means for the 5560.

The 6 channel input on the Yamahas is only 5.1 as one of the channels is for the sub. I'm not sure about the HK. So if you use this for movies you will not get DTS-ES. You'll have to matrix out 5.1 and I'm not sure how that would work.
 

Porcdoc
When you talk digital, think of the rate as
capturing a changing signal (analog) so many times or dots per second. The more dots in the one second time frame, the more faithful the digitizing is to the origional. The analog to digital conversion (ADC) or Digital to analog
conversion(Dac) is relative to the resolution
of the system. The higher the number of bits
the greater is the resolution . Resolution to
digital is like having smaller areas to call the
Dot at. Its the differance between a ruler
and a micrometer.Since "Digitizing is a stairstep
function" the smaller the step the smaller any
error would be. Jitter or "uncertainty" is the
converters (ADC) or (DAC) ability to determine
if the signal at that point is on step up or
on step down of the stairstep. Remember unlike
analog, digital is either at one place or the next
its not a smooth transition like analog, its more
like connect the dots.
 

Right,

But the timing or "arrival in sequence" of those dots is the single most important aspect to how well the convertor can do it's job of connecting the "dots".

Unlike, say, TCP/IP, where the timing of ones and zeroes is less critical (data can be reassembled with less criticality over reltively more time), digital music data is far more susceptible to those erros and our ears notice them far easier.

It all comes down to timing.

-h1pst3r
 

Derek
Ya' know, the whole 192/24 thing could be important...

...if you have speakers with a flat response to 96KHz.
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