NAD M66 - finally someone makes a decent 2-channel preamp!

[Nocko!]

Then just wait until next year. There should be a successor to the M17. The T799 might also be an option.

You're right - waiting is something I should get used to with NAD...
I am waiting since five years for a firmware update for my M17 that allows me to switch off the display.
Since four months I wait for an update for the M66 to repair at least the basics.
The M66 was announced 18 months ago and is still more than faulty. How long should I wait for the successor of the M17? I envy you for your patience.

Could someone here stop me from buying an (ugly) Stormaudio preamplifier!?
Nocko!

 

[pogo]

Could someone here stop me from buying an (ugly) Stormaudio preamplifier!?

Dirac Live processing only @48kHz
An update to 96kHz is being considered.

 

[Nocko!]

Dirac Live processing only @48kHz

Yes. That's a point in numbers. But do you hear the difference?
How do I know how Dirac processes within my M66?
Nocko!

 

[pogo]

I can hear a difference up to 96kHz files. But since we're talking about post-processing here, you should be on the safe side with 192kHz, as with the M33/(M66).
To measure this, simply apply a frequency sweep, activate Dirac Live and measure at the output.

 

[markrubin]

I keep telling myself I must stop being an early adopter/unintended beta tester…..until the next great toy is introduced….

 

[Hear Here]

In this thread. The diagram is mounted inside the M66, see also the picture above.
Of course, the signal remains analog in analog mode up to the L/R outputs. The analog signal is also tapped in parallel and runs via the digital part, which still operates the subwoofer outputs in parallel.

Thanks for the M66 block diagram. This shows that Analogue Direct avoids the ADC / DAC, so it stays clear of Dirac. However, where is Dirac and DLBC on the diagram? I can only assure it's built into the BluOS module.

 

[Hear Here]

Unfortunately I don't have any vinyl player at hand but I think we don't need one here. "Analog Direct" isn't an input but a function you can switch on with all analog inputs. So if I opt for "analog direct" I expect that the analog input signal is not touched in any way. This seems to be true for the pure left and right signal (I haven't measured this). But in addition to the pure left and right signal the M66 gives me a digital corrected signal for my subwoofers (at this point - perhaps someone else can check this ! Perhaps I am making some crude mistake here...).

So what I get in total is not an analogue, unprocessed signal, but a mishmash of a clean stereo signal and a digitally altered subwoofer signal.

Regardless of whether you - like me - have enormous problems when you want to implement a "home cinema bypass" or whether you just want to listen to your good old vinyl record unadulterated: you don't get a pure analog signal, but something else.

So there is no "Analog Direct" if you are using subwoofers. I think Pogo will recommend to switch off the subwoofers...
Nocko!

Looking at the diagram, it seems that the Main Speakers will receive an unadulterated pure analogue signal when Analogue Direct is selected, but if you have subs connected, these can be DSP's if a DL filter is selected. To achieve a non-DSP'd signal on the subs, just select No Filter. However the signal to the subs will be subjected to ADC / DAC conversion. But does this worry you, as it's only the sub 50 Hz or thereabouts and I doubt ADC / DAC will upset the signal?

 

[Hear Here]

Could someone here stop me from buying an (ugly) Stormaudio preamplifier!?

The M66 has very few rivals in what it can offer users and I've been looking for an alternative streamer / DAC / preamp that I should compare with the M66.

Unfortunately, the M66 offers so much, I'm stuck! Can anyone suggest a comparable units that includes sub processing (with DSP), a first-class control app, a good touch screen and the ability to display artwork or source info onto a connected TV screen? This last feature is present in the M33, but I was told it isn't currenty available on the M66. Can anyone clarify this point? Thanks

I've been looking at the ML 519, Grimm MU2, Esoteric N-05XD, Lumin P1 and others, but all these have features missing - and cost much more than the NAD! Any other suggestions?

 

[pogo]

A Bluesound Node Icon could also be an option for you.
I'll report back next month.

 

[pogo]

I keep telling myself I must stop being an early adopter/unintended beta tester…..until the next great toy is introduced….

I consciously accepted this with the M33 at the time and was also able to support NAD. I think after 18 months it was running to my complete satisfaction.

 

[pogo]

where is Dirac and DLBC on the diagram? I can only assure it's built into the BluOS module.

Correct.

 

[pogo]

To achieve a non-DSP'd signal on the subs, just select No Filter.

It won't work that way. Even with filters deactivated, a BluOS latency of at least 50ms is added.
A DSP will probably also be used for the crossover frequency of the subs. These low frequencies will then not be alligned with the main speakers.

 

[Nocko!]

The diagram looks more like an advertisement than a technical paper. But let's believe in it.

I also think that the left and right signals are not altered within the M66 and still present the analog input.

But from my point of view it is a no-go that the subs are playing a more or less random signal in addition to the analog input. Isn't this a catastrophe from a technical point of view? This is something Amir couldn't measure but it is there in my room and it is far more critical than a few dB signal to noise ratio.

So what I criticize is complex:

1. From a technical point of view the sum of the sound of the main speakers and the subs is definitely not "Analog Direct" or "Pure Analog" (think of your own marketing claims...).
The signal that is send to the subwoofers is not predictable - at least not for me. You get a modified subwoofer signal in dependence of the Dirac filter that was selected last before the analog input was engaged. Isn't that silly?
Yes, you could switch the Dirac filter off to get a more "clean" / unfiltered subwoofer signal. But for now I can't see or hear if there is a crossover active and what happens in the time domain. As far as I can see from the app and read elsewhere there is a minimum delay of 50ms for all signals routed through the (crappy) BluOS module. So there is still a massive impact on the signal even if a switch off Dirac filtering. Or does somebody know more about this?

2. On the other hand: In order to prevent the stereo signal played through the main speakers from being influenced by the wrong subwoofer signal, I have to switch off the subwoofers.
Really now? What do I have the four subwoofer outputs for?

3. As Pogo just confirmed, there's no getting out of this bind. You cannot use the discrete subwoofer channels with the Analog Direct function. So now my home theater no longer has subwoofers....
Nocko!

 

[pogo]

So now my home theater no longer has subwoofers....

The M66 was never intended for the integration of subwoofers into a surround setup.

 

[Nocko!]

I've been looking at the ML 519, Grimm MU2, Esoteric N-05XD, Lumin P1 and others, but all these have features missing - and cost much more than the NAD! Any other suggestions?

I have always liked Mark Levinson in former days. I was so stupid to give up a ML No 326s in favor of the M66 (I still have the ML in retirement but it is for sale).
I never ever had a Levinson machine that did something that it should not do. I really love them. But there is no Dirac
The other devices look nice, but I can't comment them. But looking at the Lumin remote, I cry when I compare it to the M66's remote...

Unfortunately I also don't know a device with a capable room correction and the other (acclaimed...) features of the M66. Because of my difficulties to create something like a "Home Theater Bypass" and because I really, really like what DLBC does with my system I was looking for something like the Marantz AV10 (as Pogo suggested) or Stormaudio or Datasat (do they still live?).

30 years ago, as a true "high-end-guy", I was an ardent advocate of separate devices. Each device should be a specialist in its field. "A radio does not belong in an amplifier" and power amplifiers and preamplifiers must in principle be separate. The power amplifier channels anyway. And never ever put something like a DAC in a preamp!
Over the years you get smarter and try something different. I would have rather not done it...

No I am sitting here, don't know where to go:
Should I further separate home theater and stereo? My head says "yes" so that I don't run into a dead end again like with the M66.

My technical mind, on the other hand, clearly tells me that I need a preamplifier that can discretely control as many channels as possible in order to be able to properly use Dirac ART and DLBC. But then I HAVE to buy a “home cinema” device because otherwise I will always have problems routing the signals through to the front and the subwoofers.

If I had to add a streamer into the equation, I would give up. But I don't see the real advantage of the streamer in the M66 either. Except that I don't like BluOS - even if there was a Lyrion client built in, that wouldn't be crucial for me. Most streaming functions can be achieved relatively cheaply these days with external devices, right?

I always thought that progress in the home theater sector was faster than in the stereo/music sector. But actually these days I would be more afraid that Spotify, Tidal, qobuz or whoever would change their API and no one at NAD would care. Then you can throw the beautiful streamer in the M66 into the trash... So perhaps you think about "separates"?
Nocko!

 

[Hear Here]

It won't work that way. Even with filters deactivated, a BluOS latency of at least 50ms is added.
A DSP will probably also be used for the crossover frequency of the subs. These low frequencies will then not be alligned with the main speakers.

So, if using Analogue Direct, the subs will be out of sync with the main speakers, with or without DL? I guess most vinyl users won't be sub fans anyway, but it must be frustrating for those who are. Subs can be switched off is using Analogue Direct, I suppose.

Personally, it wouldn't worry me as I have no analogue sources! I wonder if the recently published Stereophile review (in print only as of today) will identify and comment on this, although I note that Kal has no analogue sources himself. Stereophile reviews are normally pretty comprehensive so I'm guessing another reviewer will have looked at the Analogue Direct feature.

 

[pogo]

But actually these days I would be more afraid that Spotify, Tidal, qobuz or whoever would change their API and no one at NAD would care.

That won't happen, even if Lenbrook soon launches its own and probably technically better streaming service.

 

[pogo]

it must be frustrating for those who are.

I see it differently. An optimal integration of subwoofer and main loudspeaker can only be achieved under DLBC(/DLART) if the main loudspeakers are also adapted accordingly and this is not possible under analog direct.

 

[Nocko!]

The M66 was never intended for the integration of subwoofers into a surround setup.

Nope - that's right. But wasn't there some marketing fuss about a "home cinema bypass" in the future?

But that is not my point:
I have bought a preamp with four subwoofer outputs and a function described as "Analog Direct". So when I send a analog signal to the M66 I expect the M66 to route these signals to all preouts that are configured. At the moment it makes no difference if I connect a turntable or a DSP to an analog input. As long as "Analog Direct" is engaged the signal is crippled.
Let alone the "Home Cinema Bypass", those users who want to use a turntable or a tape always get a sub signal that is at least 50ms behind. That is what I would call a catastrophe in acoustical dimensions. At the very least, NAD should have made this clear in the manual but I think they don't even know about this.
In the next step - and this is the only step I can think of - NAD could publish a firmware that disables the subwoofer preouts if "Analog Direct" is activated. But isn't that fraud ?

What about the guy with his very small, very expensive great little speakers like a Magico A1 combined with one or two Magico Titan 15. As soon as he wants to listen analogue direct to his beloved records his subs are gone...

Am I the only one who thinks this is wrong?
Nocko!

By the way: Has someone checked if I am wrong? Is there a way to control the subwoofer directly without a time delay? Or maybe I did something else wrong?

 

[Hear Here]

I was so stupid to give up a ML No 326s in favor of the M66
I never ever had a Levinson machine that did something that it should not do. I really love them. But there is no Dirac

That ML is a simple analogue preamp so can't really be compared with the NAD. I agree that ML stuff is good (I had the 390S CDP) but the nearest to the M66 is their 519. This does all the M66 does, but no analogue sources, no included control app (it relies on Room I believe), no Dirac (I prefer not to use it anyway), but it does include a CD player. I'd be very interested if it wasn't 5 times the price of the NAD

I have no interest in home theatre or analogue, so my system is pretty simple and the M33 does all I need, although I have the excellent M50.2 as a CD player, CD ripper and hard drive music store. My speakers are good enough that no subs are needed and Dirac adds nothing to the musical enjoyment, so I prefer not to engage it - it slightly spoils the top end sparkle so more harm than good in my system. I've bought mono amps (Atma-Sphere Class D) in anticipation of the M66 that will provide everything else I need. Or the ML 519 if one turns up at an irresistible price!