• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Review and Measurements of NAD T758 V3 AVR

LTig

Addicted to Fun and Learning
Joined
Feb 27, 2019
Messages
558
Likes
654
Location
Europe
I am not disputing that at all. But it is also missing the boat.

It is like saying it is very difficult to A/B drive test two cars to pick one and therefore preference for one or the other is subjective in a negative way. Some people think speed dating is a good way to A/B test two prospects, but we do know how indicative of a good relationship that is. :)

There is a third possibility. Which is that A/B testing for sonic differences on the spot is a flawed methodology to pick one that would please us in the long term. So deficiencies of that methodology is itself irrelevant in that case.
The scientific research has shown that your last statement is wrong: long term listening results are unreliable compared to short term results. You can read about this (and much much more) in @Floyd Toole's book Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms.
 

LTig

Addicted to Fun and Learning
Joined
Feb 27, 2019
Messages
558
Likes
654
Location
Europe
I agree in general but I guess it still depends on what is considered a "poor quality" DAC, or if such a thing even exist by definition (if any such definition). Based on the fact that the T758 V3's bigger brother T777 uses the PCM1690 for DACs, I believe the T758 V3 more than likely has the same chips. I don't consider the PCM1690 a poor quality DAC (and I know you are not saying that..), [..]
In my view it makes no sense for AV products to look at the DACs inside. Allmost all DACs have way better specs than what these units deliver at the output.

I think the possibly excellent SQ of those DACs in badly performing AVRs gets swamped by noise and THD of the subsequent stages or noise and unwanted signals riding on the supply voltages of the DAC or somehow finding a way into the reference voltage inputs. I do agree that all those digital and video boards are quite a hostile environment for hires audio electronics. OTOH it is possible to get very high audio quality on a PCIe sound card within a PC (an even more hostile environment) so it must be possible to get it within an AVR as well.
 

LTig

Addicted to Fun and Learning
Joined
Feb 27, 2019
Messages
558
Likes
654
Location
Europe
Let me take an example of an extreme to make the point.

Let us say, I am very sensitive above a certain frequency range say around 14k to be concrete and so react to sound output accordingly. An audio chain that affects (enhances or diminishes) these frequencies in a certain way is considered more (or less) pleasurable than another. There is no test in our existing audio science to arrive at or to establish that conclusion. But this does not imply that such a correlation does not exist. It has nothing to do with whether I can detect distortion numbers in a blind test. It would be whether I have a correlation between what I experience as good and some particular characteristic (when neither you are I necessarily know what that is to start with) that can be shown in a controlled test.
This is exactly the reason why ASR is so picky with bad performing units. The limits of human hearing are very well known and if a unit has a SINAD of around 120 dB or more it is physically impossible for any human being to hear noise or distortion: such a unit is transparent. If a unit measures worse then all bets are off whether its limitations are audible or not, and discussions like this one rise their ugly head because one listener is happy with it but another not, and neither wants to see the situation through the others eyes.
 

RichB

Active Member
Joined
May 24, 2019
Messages
191
Likes
146
Location
Massachusetts
This is exactly the reason why ASR is so picky with bad performing units. The limits of human hearing are very well known and if a unit has a SINAD of around 120 dB or more it is physically impossible for any human being to hear noise or distortion: such a unit is transparent. If a unit measures worse then all bets are off whether its limitations are audible or not, and discussions like this one rise their ugly head because one listener is happy with it but another not, and neither wants to see the situation through the others eyes.
It also provides headroom since the THD+N increases and S/N decreases at lower volumes where most of us listen.

- Rich
 

LTig

Addicted to Fun and Learning
Joined
Feb 27, 2019
Messages
558
Likes
654
Location
Europe
There's also a point at which abandoning a simple, repeatable testing methodology and comparison protocol becomes more of a hindrance to application of the data than the expanded specificity becomes an improvement in that area.

Is there a potential for over-simplification in selecting distortion levels as the primary metric? Possibly... but then again distortion is also the primary degradation factor in the audio signal stream. At least outside of significant deviation in frequency response. In all but the most horrible products in the category (AVRs or more broadly integrated amplifiers) they are able to maintain complete linearity as far as FR is concerned - so just looking at distortion makes a great deal of sense to me.
This is the point. And measuring the DAC and the analog chain down to the output is the best way to check the performance because it is the central part of an AVR which all music must pass (I know there are people who want to use it in all analog mode but this is not the typical usage of an AVR). If this chain does not deliver its problems will swamp the performance of all better performing parts.
 

LTig

Addicted to Fun and Learning
Joined
Feb 27, 2019
Messages
558
Likes
654
Location
Europe
I am hopeful that NAD will response, and likely an honest one.

It may be worth repeating that with @amirm 's permission I forwarded his findings on the AV8805 to Marantz, and their engineering team responded in less than 10 days. :)
Would you mind telling what Marantz responded?
 

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
20,636
Likes
25,492
Location
Seattle Area
Would you mind telling what Marantz responded?
It was about the slow response of their DAC and their answer was "it is by design." They like the sound of it better back in Japan.
 

GrimSurfer

Senior Member
Joined
May 25, 2019
Messages
465
Likes
369
So, in the end, Xhattan’s conclusions were correct? Funny.
There is a difference between the logic of the herd and what is technically and acoustically correct.

Just as being as crazy as everyone else at the asylum doesn't make one sane.
 

BDWoody

Addicted to Fun and Learning
Patreon Donor
Joined
Jan 9, 2019
Messages
602
Likes
752

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
20,636
Likes
25,492
Location
Seattle Area
So, in the end, Xhattan’s conclusions were correct? Funny.
Mod note: Please don't create duplicate accounts much less to pull this stunt. This is not a game we are playing here. It is a serious discussion of equipment.
 

Blumlein 88

Major Contributor
Joined
Feb 23, 2016
Messages
6,507
Likes
6,238
Mod note: Please don't create duplicate accounts much less to pull this stunt. This is not a game we are playing here. It is a serious discussion of equipment.
I suppose he thought his opinion or ideas were twice as important as everyone else's.

I do have a question. When you know of multiple accounts do you ban both?
 

Baaha

New Member
Joined
Sep 12, 2019
Messages
2
Likes
6
Anyone told mr. Amirm that the unit he tested has the old faulty AM230 module card..? They upgraded the card in janurary i think it was. The New module card has the pre-outs up to the left, next to the usb input. The old one has the coax and optical in on the top.. Why did they upgrade? Because of noise and bad design.
This review isnt representative until tested with the module card that actually is the upgraded one.
 
Joined
Jan 12, 2019
Messages
83
Likes
115
Anyone told mr. Amirm that the unit he tested has the old faulty AM230 module card..? They upgraded the card in janurary i think it was. The New module card has the pre-outs up to the left, next to the usb input. The old one has the coax and optical in on the top.. Why did they upgrade? Because of noise and bad design.
This review isnt representative until tested with the module card that actually is the upgraded one.
I do not believe you are correct. On page 1 of the review you see a picture of the unit. According to this image it is the new card.
1568260250639.png
1568260250639.png
 

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
20,636
Likes
25,492
Location
Seattle Area
Anyone told mr. Amirm that the unit he tested has the old faulty AM230 module card..? They upgraded the card in janurary i think it was. The New module card has the pre-outs up to the left, next to the usb input. The old one has the coax and optical in on the top.. Why did they upgrade? Because of noise and bad design.
This review isnt representative until tested with the module card that actually is the upgraded one.
The owner has said it is the upgraded one. Here are the two versions:



And the one I tested:

1568260607138.png


Clearly matches the one to the right and hence "NEW."
 

Similar threads

Top Bottom