NAD 753 / 763
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Bronze Member Username: BluesPost Number: 15 Registered: Mar-04 | It might be helpful for some those of you considering NAD if a few of the resident experts on here put forth their objective opinions whether the 763 is worth an extra $400US. With the basic differences between these two fine sounding receivers being a. 110w/ch b. better power supply c. rs-232 port d. HDCD decoding and a few other minor ones. So are these worth the extra $400? I'm not sure. The only thing I see that might be worth the extra $ is the tordial power supply and maybe the flexibility of updating your software via the rs-232 port. Good luck in your quests. |
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Bronze Member Username: BuckeyeshinePost Number: 80 Registered: Feb-04 | I think the 763 also is 6.1 vs 5.1 for the 753. I could be wrong. I am not a "resident expert" but I think the question is somewhat difficult to answer since the decision can be personal. Personally, I think the rs-232 is a big feature. Is it worth $400? Maybe when you consider the ability for future upgrades in such a dynamic technology market...it could have the potential to pay for itself in the long run by forgoing a harware replacement. Who knows?? The other fact is can one afford to swing the extra $$? Totally personal. My personal philosophy is if I can afford the upgrade why not unless I am absolutely wasting money? Especially with long term purchases which you plan to live with for several years at least. I did this when I bought my 773. I tested the T763 and fell in love with it. I went through the exact same dillemma. Was it worth an extra $400 basically for 10 watts/channel and 7.1? Also an improved power supply? Basically because of the size of my room I figured the extra power wouldn't hurt even though the 763 performed awesome when I tested it and a bigger power supply never hurts either. I certainly would not have done it for the extra channel alone. That's my 2 cents. |
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Silver Member Username: JohnnyMissouri Post Number: 272 Registered: Dec-03 | JDG, The T753 is 6 channel as is the T763. I agree with you though about "whether the 763 is worth the extra $400". It is a totally personal thing. Besides the extra features listed above, these two receivers are very similar. Last October, I had nearly the identical problem. At that time, I was choosing between the 762 and the 752. Like you, I had the extra money to spend, so I just went with the more powerful unit...as Tim Taylor from "Tool Time" would agree...more power is never a bad thing. I live in a small house now, but who knows, in the future, I may have a very large space I need to fill with sound, so I liked the extra power (and in the case of the 762 vs. the 752, the extra channel as well). Bottom line, you can't go wrong with either. Go with what you can safely afford and don't question your decision once you have made it. |
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Silver Member Username: John_aPost Number: 689 Registered: Dec-03 | Just to say that all NAD receviers have toroidal power transformers, to the best of my knowledge. Take the lid off and have a look. I do not know where this idea came from that they are only in the T763. |
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Bronze Member Username: DmeisterPost Number: 90 Registered: Dec-03 | Just to say that all NAD receviers have toroidal power transformers, to the best of my knowledge NAD only advertises toroidal transformers for the 76X and 77X units. I had a 742 and, although I don't recall for certain, I'm pretty sure it had an EI transformer. |
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Silver Member Username: John_aPost Number: 692 Registered: Dec-03 | I'm pretty sure it had an EI transformer Thanks, Darryl. What is "EI"? |
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Bronze Member Username: DmeisterPost Number: 91 Registered: Dec-03 | What is "EI"? "EI" or "EL" (depending upon the specific type) transformers are the standard, square transformers you see in most receivers that don't use a toroidal transformer. |
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Bronze Member Username: Gatt767Malta Post Number: 35 Registered: Feb-04 | The toroidal Power transformer is installed only on the T762/T763/T773. Other AV receivers within the range are installed with a normal transformer |
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Silver Member Username: John_aPost Number: 695 Registered: Dec-03 | Thanks, guys. I am unfamiliar with "EL" or El". It is not word I know. Googling "El transformer" just turns up the Spanish for "the transformer". "Toroidal" just means "torus-shaped". I though they were all like that in audio equipment, but obviously that is not correct. |
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Bronze Member Username: DmeisterPost Number: 92 Registered: Dec-03 | Googling "El transformer" just turns up the Spanish for "the transformer". Here you go. Basic Transformer Definitions |
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Bronze Member Username: LandrovalPost Number: 72 Registered: Feb-04 | What exactly are the benefits of toroidial transformer? They are all just rolled wire so what's the difference? How does it actually work, is the secondary coil inside the primary? Cant remember that now. |
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Silver Member Username: John_aPost Number: 696 Registered: Dec-03 | Darryl, Brilliant link. Thanks. Transformers with toroidal cores are preferable, even essential, in all audio applications, because they are non-radiating. The three amps I own (Armstrong 621, Sony 55ES, NAD T760 receiver) all have toroidal transformers, hence my thinking there was no other sort. I cannot imagine a manufacturer putting a radiating transformer in an amp, it would be asking for trouble. I read there that "EL" "EI" etc refers to the "stamped letter shapes" of lamination cores. I still can't picture that. |
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Bronze Member Username: W9cwUrbana, IL Post Number: 29 Registered: Mar-04 | Toroidal transformers are certainly preferable, however, standard laminated transformers can also be made to not radiate fields. Many laminated transformers for audio use utilize "mu-metal" shielding providing excellent shielding against radiation of any electromagnetic fields to surrounding circuitry. Toroidal transformers do not radiate due to the inherent phase cancellation of their design. And interestingly, depending on the design and toroid-core material used, toroidal transformers can actually be cheaper to produce than a standard laminated power transformer. Why they are not used accross the board in all designs is a mystery to me. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 21 Registered: Apr-04 | John A. are you sure about the T760 having a toroidal transformer? It looks awfully square to me? I think it's a laminated transformer, probably EI type. As for toroidal vs. laminated, I've read that some believe a good laminated transformer provides better sound quality than a toroidal transformer but takes up more space and demands better shielding. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 22 Registered: Apr-04 | Picture of laminated transformer: www.custommag.com/products/laminated.shtml Picture of toroidal transformer: www.amveco.com/ |
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Bronze Member Username: DmeisterPost Number: 93 Registered: Dec-03 | are you sure about the T760 having a toroidal transformer? The 763 definitely has a toroidal transformer, at least according to NAD. As for toroidal vs. laminated, I've read that some believe a good laminated transformer provides better sound quality than a toroidal transformer but takes up more space and demands better shielding. Often, manufacturers use toroidal transformers in their higher end receivers, including Denon, Marantz, NAD, Onkyo, and so on, while they use laminated (EI or EL) transformers in their lower end gear. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 24 Registered: Apr-04 | "The 763 definitely has a toroidal transformer, at least according to NAD." Yes, but the T760 is actually more comparable to the T752-T753. I have a T760 and the transformer does not look like the toroidal transformers I've seen. The only way it can be a toroidal, is if they decided to put it inside a big square box, and why would they do that ;)? |
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Silver Member Username: John_aPost Number: 700 Registered: Dec-03 | Don, Thanks. That is sort of what I thought, too, but you know more, and in depth. Adam, Yes, my T760 transformer looks like a ring doughnut; it is a torus. Like the picture in the second link. I can maybe take a photo. Maybe they changed that in the production run......? Darryl, If toroidal transformer are better AND cheaper, as Don says....? Thanks to all. |
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Bronze Member Username: Gatt767Malta Post Number: 36 Registered: Feb-04 | T763/T763/T762 > Toroidal T750/T751/T752/T753 > Normal Transformer T793 > Huge Toroidal T163 > Toroidal T761 > ? |
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Bronze Member Username: DmeisterPost Number: 94 Registered: Dec-03 | If toroidal transformer are better AND cheaper, as Don says....? It might very well depend upon the application and the specifics of the implementation of the power supply, so I would hate to generalize like that. The fact is, cheaper receivers use laminated transformers while the more expensive ones use toroidal transformers. For instance, Denon doesn't use toroids until the 4802+, Onkyo 989, NAD 763+, Marantz 8400+, and so on. |
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Silver Member Username: JohnnyMissouri Post Number: 281 Registered: Dec-03 | Do preamps have transformers? The T163 is a preamp. |
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Bronze Member Username: LandrovalPost Number: 74 Registered: Feb-04 | Insides of Cambridge Audio 540R with ~3" toroidial transformer: http://www.hifissimo.com/images/cambridge540r-inside.jpg H/K AVR230 with laminated: http://www.areadvd.de/images/harmankardonavr230inside.jpg H/K AVR5500 (next model up from old US AVR325) laminated: http://www.areadvd.de/images/harmankardonavr5550inside.jpg Denon AVC-A1SR with toroidial: http://www.areadvd.de/images/denonavca1srinside.jpg Denon AVR1804 laminated: http://www.areadvd.de/images/denonavr1804inside1.jpg Pioneer AX-10iS (top Elite) with laminated: http://www.areadvd.de/images/pioneervsaax10isinside.jpg Yamaha DSPZ9 with toroidial: http://www.areadvd.de/images/yamahadspz9inside.jpg Yamaha RX-V640 with laminated: http://www.areadvd.de/images/yamaharxv640inside.jpg So yes, most top models have toroidial, while mid-end is usually with laminated. I couldn't find inside pictures of NAD receivers, if anyone has, or can take one it would be interesting to see. |
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Bronze Member Username: DmeisterPost Number: 95 Registered: Dec-03 | Some manufacturers, like Sony for instance, use laminated transformers across their entire product line. However, with Sony at least, I suspect that this decision is based upon cost, and not necessarily performance. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 25 Registered: Apr-04 | John A. this is most interesting. Yes they must have changed it during the production run. I wonder what they started with? Do you also have the 230V version? The sticker on the back of my T760 says G01T76004902 Johnny, yes preamps have power supplies too and so does all electronic equipment. I've also seen toroidal transformers in higher end CD-players. Darryl, I think another important factor for the companies in the choice between toroidal transformer and laminated is size. For example if you have a toroidal transformer and a laminated one of the same size, the toroidal will be more powerful. So in the higher end more powerful receivers, the power requirements would make a laminated transformer too large? |
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Bronze Member Username: DmeisterPost Number: 96 Registered: Dec-03 | I think another important factor for the companies in the choice between toroidal transformer and laminated is size However, with that reasoning... If the toroidal transformers used in AV receivers could be made smaller than laminated transformers at a comparable cost, and with comparable output performance, you would think that they would be the first choice for all AV receivers, especially those "ultra-slim" DVD/receiver combinations. After all, they wouldn't want to make the chassis any bigger than they have to. And, if they don't use toroids in everything because of their cost, you're right back to my suspicion of cost being the biggest factor. Besides, high-end receivers and amplifiers probably wouldn't see size as an important issue. Also, if you look at the guts of those high-end receivers that use toroids, you'll notice that some of them (like the Denon 4802) still have plenty of space to work with. |
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Silver Member Username: John_aPost Number: 703 Registered: Dec-03 | Adam, Yes, my T760 is 230 V. The serial no is G01T76005231 (there, the CIA will have no problem, now....). That's 329 on from yours. I will take the cover off, double-check (I am 99% sure already), take a photo, and report back, all at the weekend. In fact, I am tempted to take all my kit apart, just to see. I could have sworn by Sony power amp had a toroidal transformer, too, though I would not argue with Darryl on that until I've had another look. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 27 Registered: Apr-04 | Darryl I'm not sure I agree with the previous statement that toroidal transformers are cheaper to use. Everywhere I've looked they are more expensive. But if you also take into account that they give off less EM radiation and are smaller than laminated I still think my theory has some validity. John A. I'm looking forward to that, maybe there are other internal differences between our receivers. I don't have a digital camera unfortunately, or I'd have taken a picture and posted it too. I've mailed NAD to ask why they changed transformers and if there are any performance differences. |
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Bronze Member Username: DmeisterPost Number: 97 Registered: Dec-03 | Darryl I'm not sure I agree with the previous statement that toroidal transformers are cheaper to use Actually, I said just the opposite. ;-) I suggested that they are not used in lower-end gear because they are more expensive. In fact, I am tempted to take all my kit apart, just to see. I could have sworn by Sony power amp had a toroidal transformer, too I was specifically referring to their AV receivers (DE, DB, and ES lines). I've never looked into their ES amplifier. In my opinion, Sony stopped putting an emphasis on their "separates" product line many years ago. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 28 Registered: Apr-04 | "Actually, I said just the opposite. ;-) I suggested that they are not used in lower-end gear because they are more expensive." Yes I know  My theory was that the reason they are used in higher end equipment, is because they are smaller and give off less EM radiation. Not because they sound better ;) |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 29 Registered: Apr-04 | Well I just took my T760 apart again, and it definitely doesn't have a toroidal transformer. It has a huge 11cm x 10cm x 12cm laminated transformer. I couldn't find any markings on it except these numbers: 1806-3518-0 HY1050001-P CBE 9950 OK OK I'll stop with the uninteresting excess information ;) |
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Bronze Member Username: W9cwUrbana, IL Post Number: 30 Registered: Mar-04 | John A: As one who has used not only low frequency (LF) toroids, but HF and VHF toroids in the design of audio and RF circuits, it generally is not one of a major cost differential. Standard EI laminated transformers that are designed for high-current and low EMI radiation are not inexpensive. Transformers in general are one of the more costly parts in a design. Unless the toroids used for the power supply design are not ones I'm familiar with, the cost ratio should be similar or slightly less for the toroidal transformer. The toroidal transformer is certainly better "by design" and is used almost exclusively in all switching-mode power supply designs and in many linear power supplies. Most past audio receiver designs were of the linear power supply type. That said, a number of newer receivers "appear" to be using a switching mode design, better known as simply a "switcher." Interestingly, several Marantz' newer models weigh less than the previous generation. This is most likely due to a change in the power supply design, and they may have gone to a switching power supply. They are much more efficient than a linear supply, weigh less (since the transformer is smaller), produce less heat, and have much superior regulation. However, there is one big downside - EMI/RFI generation or "hash." One last comment on toroidal supplies . . . they are construed from a marketing point-of-view to be much more desirable than a standard laminated transformer. |
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Silver Member Username: HawkHighlands Ranch, CO USA Post Number: 520 Registered: Dec-03 | I copied the following from the website of ATI, makers of some very good amplifiers (many of you may remember this company under its old name of "SAE"). Anyways, the following recounts one of the advantages of ATI's amplifier architecture which uses toroidal power supplies: "Toroid Transformers: 40% more efficient than EI type. Separate bi-filar windings for each channel guaranty lower noise and crosstalk." My 753 does not have a toroidal, but has the EI type instead, which I was aware of when I bought it. I do not believe toroidals are cheaper, otherwise you would see them in everyone's amps. Instead, they tend to be in the better amps (and receivers) at the higher price points. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 30 Registered: Apr-04 | Well I got some info on the transformers in the newer NAD receivers: T753: 1 EI-transformer with 2 crossed layers of mu-metal and exterior copper screen. T763: 1 Holmgren toroidal transformer T773: 2! Holmgren toroidal transformers I'm still waiting on some detailed specs on the power output of the T753. |
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Bronze Member Username: W9cwUrbana, IL Post Number: 31 Registered: Mar-04 | Hawk: Toroidal transformers are unquestionally better than standard EI laminated transformers due to their inherent phase cancellation of noise and radiation products. However, they are not necessarily more expensive depending upon the toroid core material used. Certainly, it could be the case where the hi-fi manufacturers are using a special core material, or they do not purchase the cores or transformers in sufficient quantity to meet cost-efficiency. Nevertheless, they "can" be cheaper than a standard laminated transformer. I've worked in engineering and manufacturing in the consumer and defense electronics industries since 1968, and my experience substantiates this fact. When designing a new product, the most expensive parts in the design are in decreasing order of price: 1). Cabinet and sheetmetal parts, 2). Transformers, 3). Special IC's, such as DSP CPU's or proprietary memory/logic chips, 4). Display units, LED or LCD, 5). Switches, pots, etc, and 6). Power output transistors or IC's, 7). All of the remaining IC's, transistors, IC's, resistors, caps, etc. (all of these are known as "popcorn parts" in the industry). Sometimes you may swap the number 2). and 3). positions depending on the expensive of your DSP engine or special memory chips. Especially on high-end audio products, you wouldn't believe the cost of the cabinet parts, most of which are fabricated by an outside firm at very high costs. Would I choose a toroidal-core power transformer over a standard laminated-type, absolutely. I just wouldn't pay a price premium to get it given what I know from my experience in the industry. |
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Bronze Member Username: Gatt767Malta Post Number: 37 Registered: Feb-04 | Look at the massive size of the NAD T762 Toroidal Transformer! |
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Silver Member Username: John_aPost Number: 718 Registered: Dec-03 | Great photo, Robert! |
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Silver Member Username: John_aPost Number: 719 Registered: Dec-03 | Don, Thank you for the real word on costs. "One last comment on toroidal supplies . . . they are construed from a marketing point-of-view to be much more desirable than a standard laminated transformer." Yes, but it is the industry which tells us so! Was there ever a manufacturing area to equal hi-fi: just a little suggestion can go such a long way! |
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Silver Member Username: John_aPost Number: 722 Registered: Dec-03 | The NAD T760 has a laminated transformer. I was quite wrong in saying it was toroidal. Apologies, Adam, Robert and others. I also find a small laminated transformer in the NAD T533 and T532 DVD-players. Here is the T760.  |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 35 Registered: Apr-04 | No need to apologize John I wasn't sure myself until I had seen a picture of a laminated transformer, because the protruding copper shielded windings (not visible in picture) does make it look a bit torus-like in shape. |
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Silver Member Username: John_aPost Number: 728 Registered: Dec-03 | Adam, Nice of you to say that, but there is no way that is a torus! I am doing a grip-on-reality check. I recently took apart and Armstrong 621 and my Sony power amp. They both have toroidal transformers. I'll spare you the photos! I also took photos of the T533 and T532 DVd-players. I included them in a post on the T533 thread to try to give a more sober review, but the browser crashed and I lost it all. I will try again later. |
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Silver Member Username: John_aPost Number: 729 Registered: Dec-03 | Don, and others, I refuse to lose sleep over not having a toroidal transformer! But let me just say that manufacturers cannot have it both ways: either a toroidal transformer is a desirable feature, or it is not. If it is, then its absence is undesirable. NAD seems to be as "economical with the truth" as other brands/manufacturers on this and other issues. For example, they trumpeted the Crystal DACs in the T532, but are silent on the subject of DACs in the T533. You might draw the conclusions that the T533 has inferior DACs; that having Crystal DACs was no big deal anyway; or that they just forgot to mention it. I imagine that money is changes hands over naming of parts, just as money changes hands to have names such as "NAD" or "B&W" casually dropped in movies. By the way, who is "Holmgren"? |
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Bronze Member Username: LandrovalPost Number: 79 Registered: Feb-04 | "The T 973... It features the new, proprietary "Holmgren" transformer, which uses a special core design and materials to enhance efficiency and make the transformer less sensitive to DC offsets." Though I dont know who Holmgren is. The CA 540R seems to be the cheapest AV-receiver with a toroidial transformer. When compared to T743 it is 6.1, but it's harder to use and loses a bit in sound quality. Perhaps it has more power and is more efficient in terms of power usage, but maybe those aren't the most importat things when selecting a receiver. What do you think? |
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Bronze Member Username: LandrovalPost Number: 80 Registered: Feb-04 | "The special Holmgren toroidal transformer has less hum and magnetic leakage than conventional toroidal transformers but retains the usual benefits of high efficiency and high power to weight ratio." Maybe it's something special, maybe not. |
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Bronze Member Username: DocdatCopenhagenDenmark Post Number: 37 Registered: Apr-04 | "The CA 540R seems to be the cheapest AV-receiver with a toroidial transformer. When compared to T743 it is 6.1, but it's harder to use and loses a bit in sound quality. Perhaps it has more power and is more efficient in terms of power usage, but maybe those aren't the most importat things when selecting a receiver. What do you think?" Well as I see it you can have plenty of power without having good sound quality, but you can't have good sound quality without enough power ;) So yeah a powerful receiver doesn't necessarily sound good, but a powerful transformer is still important. |
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Silver Member Username: John_aPost Number: 735 Registered: Dec-03 | I pass on the subject "Holmgren". "Toroidal", in contrast, means something. Beware the power of names. THX-LucasArts are now approving and licensing cables.... amongst which the first batch are Monster cables. I would rather spend my money on the product than a badge, anytime. BTW "Holmgren" not "Holmgren", I am fairly sure. Adam will know better! |
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