Review and Measurements of NAD T758 V3 AVR

[Roland]

I don't know if it's botched. I guess it is - it's so easy to ruin the performance of a jewel of receiver just by declaring a wrong type for a single variable somewhere in one line of code. Or may be a result of comprimises required to place the product where it is on the market (price and feature wise). It may be quite well an intentional decision: take this bad measuring receiver for cheap - want 20dB better? Shell another $2000 and it's yours (I doubt this but practice became routine nowadays). However the entire design result worked surprisingly well for me so it seems the right comprimises were taken for a set of potential customers that have no alternative on the market. That in itself is an achievement. I would like as an engineer to make the right compromises to get such a unique and satisfying proposition in a market slot. And incredible as it seems, these 20dB less SINAD hurt my eyes on the graphs but not my ears. Just how deaf I must have been all these years... But still, I really love good measuring toys, it's a weakness I cannot overcome It's just that I have a so bad room that a good measuring amp couldn't hide it's problems

I agree, the consensus on this forum suggests that there is no audible difference between a “bad” and “good” measuring receivers, which is why those who have added expensive power amps are so reluctant to explain how they sound better than the receiver’s internal amps. If this is true then measurements themselves as a guide to purchasing are purely for people to feel good about how their amps measure, even though there is no audible evidence or benefit

 

[dannut]

take this bad measuring receiver for cheap - want 20dB better? Shell another $2000 and it's yours (I doubt this but practice became routine nowadays)

That requires competence on behalf of the manufacturer
It seems like all manufacturers can spec better components (on paper at-least) with higher price bracket products, but what difference does it make, if all the lines are affected with the same type of bug in the implementation side?

 

[LTig]

Not trivial. An AVR is a very complex device, unlike a dongle.

Exactly. The main problem as far as I can see are all the analog circuits behind the DACs. Switches, volume controls, whatever.

I think there is a relatively simple way to overcome those problem if one chooses really good DACs: just do everything on the digital side. Meaning not only standard audio processing like multichannel decoding, tone controls and room EQ, but also routing and volume control. Then you just connect the analog outputs of the DACs to the analog output stages and you're done. You can put all the DACs and output stages on one PCB and shield it from the remaining digital electronics. If you need an analog input just add a good ADC.

RME shows that this can be done. Agreed, their ADI-2 models use a 3 or 4 step volume control to cover a very wide range of output voltages but I don't think this would be required for an AVP if one stucks with 4V balanced and 2 V unbalanced.

 

[tjcinnamon]

Given how buggy this AVR is, has it been re-reviewed? I would not be surprised if a different one gave completely different results...

 

[peng]

I agree, the consensus on this forum suggests that there is no audible difference between a “bad” and “good” measuring receivers, which is why those who have added expensive power amps are so reluctant to explain how they sound better than the receiver’s internal amps. If this is true then measurements themselves as a guide to purchasing are purely for people to feel good about how their amps measure, even though there is no audible evidence or benefit

I would say while this seems true in most cases if we consider only those Amir has measured so far. Still, a case can be made that if it gets as bad as this NAD (T758V3), some people with good hearing might be able to hear its relatively high THD+N and IMD under some conditions. For SINAD <60 dB and IMD > -50 dB at the extreme listening levels, both low and high, I think it is likely one would hear something depending on the contents, such as noise and IMD during the quieter passages and THD during the loudest parts when listening to within a few dB or ref level, depending on the speakers and seating distance. That's only in theory, I don't have the gear to experience it myself, unfortunately, or, fortunately..

To me, it is not just about feeling good knowing the device measured well enough, but also about confidence, or lack of. That is, if the manufacturer couldn't get better numbers than their lower cost competitors, what else could they have missed, or not getting right? My AV8801 costed me over $3K, and it was reviewed and measured by Hometheaterhifi.com, in which it was revealed that its volume control chip was the same one use in a $250 Yamaha RXV367! That didn't make me feel good at all. That chip is obviously the bottleneck, the excellent PCM1795 DAC behind it wouldn't matter much if at all, they could have just used the same DAC chip used in their AVRs at the time. That's just science and simple logic, not even debatable. Then there's more when I read on, that its HDAM is not all that discrete as advertised, some low grade OP amps were used. All those got replaced with a more discrete board in the subsequent year models AVP and AVRs, after being called out by the magazine, though that cheap LSI volume control chip was kept in the even more expensive AV8802A and did not get upgraded until around 2017. After that, it seemed logical to me that all those marketing talks on their website don't seem credible at all. If and when I went back to AVP, I likely would stick with Marantz (only the 8000 series) but would likely be because I trust the others even less.

So again, its not just about feeling good, but also the confidence in the level of the "engineering excellence" the products demonstrated by their bench measurements; and not have to feel like being cheated on the flip side, that is, paying more and getting less. That's just my opinion and I am biased because of my personal experience with two Marantz AVP, the second one being a flagship model.

 

[Fizzy Duck]

Hi all,

I recently bought one of these, and have noticed quite a significant amount of distortion, regardless of volume level.

It's most notable with simple audio, such as classical music, but even when playing audio from my Xbox Series X, there's noticeable distortion.

I'm only driving 2 channels currently.

I spoke to NAD about this, and they suggested turning off all listening modes, but this hasn't helped at all.


Having read the measurements from the review, they don't seem great?

 

[peng]

Hi all,

I recently bought one of these, and have noticed quite a significant amount of distortion, regardless of volume level.

It's most notable with simple audio, such as classical music, but even when playing audio from my Xbox Series X, there's noticeable distortion.

I'm only driving 2 channels currently.

I spoke to NAD about this, and they suggested turning off all listening modes, but this hasn't helped at all.


Having read the measurements from the review, they don't seem great?

Did you buy it new, or used? If new, I suppose you can return it if NAD support is not helping.

 

[Fizzy Duck]

Did you buy it new, or used? If new, I suppose you can return it if NAD support is not helping.

Used

 

[Shoegazer]

Hi all,

I recently bought one of these, and have noticed quite a significant amount of distortion, regardless of volume level.

It's most notable with simple audio, such as classical music, but even when playing audio from my Xbox Series X, there's noticeable distortion.

I'm only driving 2 channels currently.

I spoke to NAD about this, and they suggested turning off all listening modes, but this hasn't helped at all.


Having read the measurements from the review, they don't seem great?

I had two seperate T758 V'3's (one with the old module, one with the newer) & both exhibited distortion like you're describing. I first noticed it with ambient music when notes are bare. It was usually inaudible when there's a lot of sound going on. With headphones plugged into the 758, no distortion. Using the NAD with external amps (in my case, another NAD unit: C272), no distortion again. Only distortion with the internal amps. Try these if it's an option.

Other people have reported the same on avsforum. Both of my units also had unacceptable amounts of idle background noise that I haven't experienced through any other receiver. Although the NAD's did sound very good (when the distortion/noise wasn't audible), I ditched them for an Anthem & am happier.

 

[Fizzy Duck]

I had two seperate T758 V'3's (one with the old module, one with the newer) & both exhibited distortion like you're describing. I first noticed it with ambient music when notes are bare. It was usually inaudible when there's a lot of sound going on. With headphones plugged into the 758, no distortion. Using the NAD with external amps (in my case, another NAD unit: C272), no distortion again. Only distortion with the internal amps. Try these if it's an option.

Other people have reported the same on avsforum. Both of my units also had unacceptable amounts of idle background noise that I haven't experienced through any other receiver. Although the NAD's did sound very good (when the distortion/noise wasn't audible), I ditched them for an Anthem & am happier.

I’m tempted to do the same, having come from an MRX 310.

My only concern is the the buggy ness of the new Anthems.

 

[peng]

I suggest people trust specs and measurements, and with due respect not pay much attention to all sorts of subjective reviews by owners about certain sound signatures of boutique brand names. Anthem is at least honest about their products are not designed to have sonic flavor but to play exactly what's in the recording, yet some people will still claim they have a different sound than others for no apparent reasons.

 

[tjcinnamon]

I’m terrible at voltage math/logic. If a Purifi amp has a total voltage gain of 27 (14 input buffer, 13 purifi), then what will the NAD put out based on it’s PreOut voltage for a 4Ohm speaker?

 

[Robesini]

well the NAD has a very decent amplifier section. most speakers will be driven more accurate. just wondering what the distortion would be if the final result is measured with a microphone and analyzed.

 

[markus]

well the NAD has a very decent amplifier section. most speakers will be driven more accurate. just wondering what the distortion would be if the final result is measured with a microphone and analyzed.

You would see the same performance while the data would be much harder to interpret as speaker, mic and room add a ton of additional variables.

The problem with Amir's test is that he didn't explore "safe" output voltages enough. Obviously 2V drives the device into distortion. But then NAD didn't specify what the max. "safe" output voltage is either.

 

[Dj7675]

The problem with Amir's test is that he didn't explore "safe" output voltages enough. Obviously 2V drives the device into distortion. But then NAD didn't specify what the max. "safe" output voltage is either.

The testing has evolved quite a lot, partly because of this review and others. Amir only test 2V for singed ended and 4V balanced. He continues to do that but now there are generally another graph showing the output and where clipping begins. Even in this review, he posted the measurement at 1V (-6 on the master volume).

The test Amir does now is very informative. For example on the X8500 is below. You can see what the performance is at different voltages.

So I don't think it is fair to say he doesn't explore safe voltages when he takes the time to show us the graphs like the above now on the x8500. This tells us everything we need to know it seems to me.

 

[markus]

The testing has evolved quite a lot, partly because of this review and others. Amir only test 2V for singed ended and 4V balanced. He continues to do that but now there are generally another graph showing the output and where clipping begins. Even in this review, he posted the measurement at 1V (-6 on the master volume).
View attachment 133386

The test Amir does now is very informative. For example on the X8500 is below. You can see what the performance is at different voltages.
View attachment 133389

So I don't think it is fair to say he doesn't explore safe voltages when he takes the time to show us the graphs like the above now on the x8500. This tells us everything we need to know it seems to me.

I know that he now does SINAD over voltage. It was actually my suggestion Anyhow, he didn't do that for the 758v3 which made it look worse than it actually is. He should have stopped and questioned his test methodology when he saw that the performance for 1V was so much better compared to 2V.
2V/4V amp sensitivity is NOT an industry standard. It is common but there's a ton of amps out there that optimally operate at other input voltages.

 

[Dj7675]

I know that he now does SINAD over voltage. It was actually my suggestion Anyhow, he didn't do that for the 758v3 which made it look worse than it actually is. He should have stopped and questioned his test methodology when he saw that the performance for 1V was so much better compared to 2V.
2V/4V amp sensitivity is NOT an industry standard. It is common but there's a ton of amps out there that optimally operate at other input voltages.

I should have ready you comment a bit more closely.... you also said "didn't" and not "doesn't" That was a great suggestion to include that SINAD over voltage graph. While the SINAD chart does only show 2V/4V performance, I had always hoped that it could also include best performance output too.

 

[peng]

I should have ready you comment a bit more closely.... you also said "didn't" and not "doesn't" That was a great suggestion to include that SINAD over voltage graph. While the SINAD chart does only show 2V/4V performance, I had always hoped that it could also include best performance output too.

Agreed, at least Amir did measure the T758V3 (if that's the one being discussed), at 0.987 V, and SINAD was 88.5 dB.
That means for those who don't listen very loud, sitting not too far away, having speakers with good sensitivity, and pair it with power amps with reasonably high gain, SINAD is not likely to be an issue.

IMD seems too high though, it may not be audible but I see no reason to take the chance when there are lower priced alternatives that performed much better in SINAD and IMD, too important measurements imo.

 

[markus]

IMD seems too high though, it may not be audible but I see no reason to take the chance when there are lower priced alternatives that performed much better in SINAD and IMD, too important measurements imo.

A reason could be Dirac Live

 

[peng]

A reason could be Dirac Live

Could be, but for those who are happy with EQ the below 300 Hz range, I dare say in a blind test few could barely hear the difference between XT32, AARC, Dirac Live or whatever. Just look at the REW graphs posted on various forms, including mine, you can see why I am so confident.

I just took another look and noticed that this thing did not do good on the other tests such as linearity, THD Vs frequency, 32 tones etc... Everything seems to border on the what many may consider the thresholds of audibility. If I want a NAD, I would bite the bullet and pay the premium for the T778 for sure.