NAD M33 Streaming Amplifier Review

[pogo]

Where do the distortion happens in which track at what time? You mention, the distortion is audible at -21 or -18db.
Kaboo mentioned “The distortion will be heard at all levels of volume”.
What is right?

Follow to my post #494, there is also a music example including the time stamp in the picture.
Both is right, at all levels of volume as Kaboo described and my confirmed issue by NAD last year, which is audible after the update now at -21 with DL enabled.

Second replay from NAD support: (Clipping bug confirmed by NAD engineers. Bug limited to only those who use subwoofer and never run Dirac live or use Dirac filters with too levels too high).

 

[Dieter Leonard]

Follow to my post #494, there is also a music example including the time stamp in the picture.
Both is right, at all levels of volume as Kaboo described and my confirmed issue by NAD last year, which is audible after the update now at -21 with DL enabled.

Time stamp in the picture ???

 

[pogo]

Time stamp in the picture ???

Sorry, you are right.
I have not uploaded the screenshot.

Title information:
BRUNETTE MODELS - Last Poem
Fly with me Margo

Distortion within the first 10 seconds.
Attention, slowly approach of the volume is necessary!
If you can hear it at all, because you have different filter settings.

 

[Kaboo]

Sorry, you are right.
I have not uploaded the screenshot.

Title information:
BRUNETTE MODELS - Last Poem
Fly with me Margo

Distortion within the first 10 seconds.
Attention, slowly approach of the volume is necessary!
If you can hear it at all, because you have different filter settings.

Here is my latest from NAD on the issue

Hello Rene,

Thank you for your reply.

This issue is a high priority on the engineering team's list to resolve but not a simple fix, hence it has taken longer than expected to resolve.

The distortion does not affect all tracks, just a few that were recorded HOT with inter-sample clipping.

The distortion can be resolved by setting "Tone Controls - ON", or if one does not have subwoofers connected, setting "Select Attached Speakers - No Subwoofer".

Again I apologize that we do not have a more immediate solution for you now, but we will let you know when a fix is released.

Kind Regards,

Bob Moran
NAD Support Specialist

 

[witwald]

You are right Kaboo. The more I listen, especially with headphones (with Dirac off, obviously) I realize it was not just a reduction in decibels with Tone Controls on, it flattens the soundstage a bit. I mean, at least I think so, it's hard to tell if it is just the –6db affecting my perception or not.

It's just your perception being affected by the significant 6 dB drop in output level. If you increase the output level by 6 dB using the volume control, then you should perceive that the soundstage will unflatten back to its original state. Our ears are nonlinear in their frequency response with respect to sound level, so a 6 dB change elicits a large subjective change in sound quality.

 

[EB1000]

Only when subwoofer is enabled?

If I have no subwoofer, can I go back and listen to music instead listening to distortion?
Pogo says No! Because even with subwoofer disabled but Dirac enablecdthere are distortion...

You guys make me crazy... ;-)

If Dirac filters where created with subwoofer enabled, turning the sub off will not help if Dirac is on. If Dirac filters were created with subwoofer off, no more distortion using the default NAD target curve at least.

 

[pogo]

If Dirac filters were created with subwoofer off, no more distortion using the default NAD target curve at least.

But it does in my example!

 

[pogo]

Here is my latest from NAD on the issue

Hello Rene,

Thank you for your reply.

This issue is a high priority on the engineering team's list to resolve but not a simple fix, hence it has taken longer than expected to resolve.

The distortion does not affect all tracks, just a few that were recorded HOT with inter-sample clipping.

The distortion can be resolved by setting "Tone Controls - ON", or if one does not have subwoofers connected, setting "Select Attached Speakers - No Subwoofer".

Again I apologize that we do not have a more immediate solution for you now, but we will let you know when a fix is released.

Kind Regards,

Bob Moran
NAD Support Specialist

When is this feedback from?

 

[Kaboo]

When is this feedback from?

It was on the 15th found in my spam folder

 

[pogo]

It was on the 15th found in my spam folder

That gives hope that there will be a solution in the medium term and that NAD still has this issue on its priority list.

If this is properly implemented here in the M33, it has great advantages over the coordination of individual components (matching components, gain settings, cabling, ...), as some users repeatedly have problems in their setups with pre-amp, dac, streamer, minidsp, amp, ... and so on.

 

[pogo]

Before everyone sets their hair on fire, try to replicate this. I just applied today’s BluOS update for my C658. Sounds like before or flat, afraid to say. I then opened the DiracLive software on my Mac laptop and loaded the project while music is playing. Only do this with your volume low because it immediately gets loud(er). Confirmed with the volume display on the C658. Maybe jumped by 10db. Quit DiracLive and everything remains. And to me it changes a number of things. IOW, it ain’t flat, at least not on my system. Confirmed that all curves are working. I think there might be an issue with the handshake between DiracLive and BluOS. And opening DiracLive while playing music through BluOS somehow clears the cobwebs. Someone try this please.

Confirmed yesterday on my M33, different behavior (maybe speaker killer) since the last BluOs Update ;-)

 

[HazelT]

For the "distortion issue on tracks that were recorded HOT"; Does it also affects the M10 and C658? I see it being discussed a lot here but didn't see any mention to it in the M10 thread

 

[AdamG]

For the "distortion issue on tracks that were recorded HOT"; Does it also affects the M10 and C658? I see it being discussed a lot here but didn't see any mention to it in the M10 thread

Welcome Aboard @HazelT.

 

[Touchstone]

A naive question ...

In testing the M33's DAC, Amir reports:

As usual we start with our dashboard of feeding the unit digital content and measuring what analog output we have out of the pre-out. First measurement was disappointing:

Distortion was extremely low but that rise in low frequency noise was not something I had seen. I then realized the amps were on so I turned them off and performance much improved:

There are a few subsequent comments. @BillH says:

... I'm a little confused why i would want an AVR that I have to turn the amplifiers off for the DAC to be anywhere near state of the art.

Maybe he's just being facetious, maybe it indicates a real problem, I'm not sure. I'm not sure I'd know how to be sure. But @Soniclife later asks:

Can you explain why this does not show up when you tested the speaker outs?

Amir then adds, by way of explanation:

Different situations. In DAC testing the volume is set to -6 dB which means the amps are running at full power. In sharp contrast, the amplifier test is done at just 5 watts so the amp is not remotely stressed. Is this what were asking?

There's no subsequent discussion of this that might have teased out issues about causes and consequences, and since the noise floor is below audibility it probably doesn't matter much, but I'm left with a question about whether this is a real problem (about the circuitry of the M33) or an artefact of the test conditions (with the 'amps ... running at full power') and what that means.

I'd be happy to receive any enlightenment, even if begins 'listen, stupid ...'

 

[BillH]

A naive question ...

In testing the M33's DAC, Amir reports:



There are a few subsequent comments. @BillH says:


Maybe he's just being facetious, maybe it indicates a real problem, I'm not sure. I'm not sure I'd know how to be sure. But @Soniclife later asks:


Amir then adds, by way of explanation:


There's no subsequent discussion of this that might have teased out issues about causes and consequences, and since the noise floor is below audibility it probably doesn't matter much, but I'm left with a question about whether this is a real problem (about the circuitry of the M33) or an artefact of the test conditions (with the 'amps ... running at full power') and what that means.

I'd be happy to receive any enlightenment, even if begins 'listen, stupid ...'

My comment was meant to be reflective of the fact that this is a fairly expensive piece of audio equipment by an established company with very mediocre performance from an objective point of view (when you turn the amps on). Is it sonically good enough? Probably. Am i impressed? No. The fact that the performance degrades when the amps are on is, in my opinion, reflective of mediocre attention to engineering details.
Why make this when you are so close to making something much better?

 

[Touchstone]

My comment was meant to be reflective of the fact that this is a fairly expensive piece of audio equipment by an established company with very mediocre performance from an objective point of view (when you turn the amps on). Is it sonically good enough? Probably. Am i impressed? No. The fact that the performance degrades when the amps are on is, in my opinion, reflective of mediocre attention to engineering details.
Why make this when you are so close to making something much better?

Thanks Bill.

I'm assuming (but it's only an assumption) that the problem has to do with how the outputs are wired rather than something to do with the DAC. Either way it doesn't speak too well of the M33 (or NAD), as you say. But I suppose it raises a supplementary question: is this an engineering issue or a factory one (a fault with the particular amplifier)?

Amir doesn't speculate on this and there's presumably no way of knowing without a tear-down (not within his remit). I asked NAD technical support about it but just got some PR guff in reply.

Addendum: I don't, by the way, think being facetious is necessarily a bad thing and I hope I didn't give that impression. It's a useful rhetorical weapon, especially round these parts with all the subjectivists dropping by from time to time for a skirmish.

 

[Beershaun]

My comment was meant to be reflective of the fact that this is a fairly expensive piece of audio equipment by an established company with very mediocre performance from an objective point of view (when you turn the amps on). Is it sonically good enough? Probably. Am i impressed? No. The fact that the performance degrades when the amps are on is, in my opinion, reflective of mediocre attention to engineering details.
Why make this when you are so close to making something much better?

I think that is the nature of the beast with any integrated product. The SINAD performance you are seeing is the performance of DAC+AMP. Amps have lower SINAD performance due to the complexity of creating a high power higher voltage analog device. Integrated products like AVRs and integrated amps all take a SINAD hit at the pre-amp output whenever the amps are being used.

RE: for the price point. I think you are paying for the complete package of full featured streaming, full Dirac DSP and room correction, DAC, amp, multiple digital inputs, sub output, 200wpc, all in 1 beautiful convenient package that is user friendly and aesthetically pleasing. While not cheap, there is nothing else that packages all that above into an attractive user friendly package for that price with that SINAD.

Yes you can build all that with separate components for less with possibly better SINAD, but you are cobbling it together, integrating it yourself, and it won't be as attractive or user friendly to your friends and family.

PPS: to your point on SINAD not as impressive as it could be, I see the M33 as an inflection point for integrated units. We are seeing the full recipe for what we all want in one package in it's first iteration. I have high hopes that future iterations that will present improved fidelity, more power, and lower price points as this recipe of Bluesound+DIRAC+SOTA DACs+Purifi in 2.1 systems matures over time. I just hope this formula catches on and more companies release competing products and sell a bunch so we see things get better and cheaper.

 

[BillH]

I think that is the nature of the beast with any integrated product. The SINAD performance you are seeing is the performance of DAC+AMP. Amps have lower SINAD performance due to the complexity of creating a high power higher voltage analog device. Integrated products like AVRs and integrated amps all take a SINAD hit at the pre-amp output whenever the amps are being used.

I see no reason why it has to be this way. If one can make a good DAC and a good amp, one can isolate the subsystems and presumably make a good DAC+Amp. Instead they, and many others, choose to make a mediocre integrated amp.

When we discuss speakers we often talk about design tradeoffs. in this case I believe the only tradeoff is performance versus money and effort.

 

[Beershaun]

I see no reason why it has to be this way. If one can make a good DAC and a good amp, one can isolate the subsystems and presumably make a good DAC+Amp. Instead they, and many others, choose to make a mediocre integrated amp.

When we discuss speakers we often talk about design tradeoffs. in this case I believe the only tradeoff is performance versus money and effort.

Yes you are correct. Correct. It's a trade off on performance vs. cost and time. They have to hit a price point and need to hit a delivery schedule, and have a budget to stick to.

If they continue to develop this product they will apply what they learned from the M33 but didn't have the time or resources to incorporate, into the next revision of the device. Maybe it will be called the iphone 3GS.

 

[Serg]

I think that is the nature of the beast with any integrated product. The SINAD performance you are seeing is the performance of DAC+AMP. Amps have lower SINAD performance due to the complexity of creating a high power higher voltage analog device. Integrated products like AVRs and integrated amps all take a SINAD hit at the pre-amp output whenever the amps are being used.

RE: for the price point. I think you are paying for the complete package of full featured streaming, full Dirac DSP and room correction, DAC, amp, multiple digital inputs, sub output, 200wpc, all in 1 beautiful convenient package that is user friendly and aesthetically pleasing. While not cheap, there is nothing else that packages all that above into an attractive user friendly package for that price with that SINAD.

Yes you can build all that with separate components for less with possibly better SINAD, but you are cobbling it together, integrating it yourself, and it won't be as attractive or user friendly to your friends and family.

PPS: to your point on SINAD not as impressive as it could be, I see the M33 as an inflection point for integrated units. We are seeing the full recipe for what we all want in one package in it's first iteration. I have high hopes that future iterations that will present improved fidelity, more power, and lower price points as this recipe of Bluesound+DIRAC+SOTA DACs+Purifi in 2.1 systems matures over time. I just hope this formula catches on and more companies release competing products and sell a bunch so we see things get better and cheaper.

I agree with you Beershaun. This unit is just the beginning of a new trend; I'm sure of it. When looked as a package, it clearly is the best out there. Do I wish it measured better? Absolutely! Then again, the single box convenience (if done properly) is worth a little hit in sonic performance to me.