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

[vddobrev]

Dirac Live is very good on my receiver NAD T778, I like what it does to correctly set distance and phase of all speakers. I use it below 350Hz.

I have not had much luck with it on M66.
My biggest problem with Dirac Live and M66 is the Analgue Direct mode in M66.
By all means, any and all digital signal processing must be disabled in this mode for a pure analogue path, as stated in the manual.
Instead, there a couple of problems with M66:
1. Dirac Live filter is applied to Analgue Direct, defeating the analgue bypass mode. This causes approximately 10dB gain, extremely loud.
2. Subwoofers are active, defeating the analgue bypass mode. Also, the subwoofers are not in sync with L/R.

There should be no Dirac Filter applied to Analogue Direct, and subwoofers should not be active.
NAD/BluOS support kind of acknowledged this as a problem about a couple of weeks ago.
But I am no beta tester... this should have been tested and resolved before releasing to market.
I am more and more inclined to think that the arrival of DLART to M66 is more of a NAD problem, rather than Dirac. I mean NAD/BluOS can't properly integrate DL and DLBC, not to mention DLART.

 

[pogo]

Dirac Live filter is applied to Analgue Direct, defeating the analgue bypass mode. This causes approximately 10dB gain, extremely loud.

No filters are applied to Analgue Direct. The 10dB difference comes from the Dirac Live headroom reservation.

 

[vddobrev]

No filters are applied to Analgue Direct. The 10dB difference comes from the Dirac Live headroom reservation.

I don't care, the fact of the matter is if I am listening to Coax 1 input with Dirac Filter applied, and then switch to Analogue Direct (e.g. Line 1), Dirac should be inactivated all together. Instead I am hearing a huge jump in SPL, unless I deactivate the Dirac filter.

 

[pogo]

This is correct and no filters are applied in Analogue Direct!
If you optimize your DL target curve (add a offset), you will no longer have this difference.

 

[pogo]

 

[vddobrev]

If you optimize your DL target curve (add a offset), you will no longer have this difference.

Please enlighten me.
Perhaps you also have an explanation why subwoofers are active in Analogue Direct.

 

[vddobrev]

This is correct and no filters are applied in Analogue Direct!

Please let me know what is correct? Is it that if and when I have Dirac filter enabled, the Analogue Direct will be 10 dB louder?

 

[pogo]

The sub outputs should of course be deactivated in Analogue Direct mode by NAD.
If you show me your Dirac Live target curve, I can tell you what needs to be optimized.

 

[vddobrev]

If you show me your Dirac Live target curve, I can tell you what needs to be optimized.

I used the default Dirac target curve.

Edit: But why tinker with this? Shouldn't Dirac be disabled altogether on the Analogue Direct. You seem to be very knowleadgeble, why not just explain, rather than throw a one-liner response to less-informed people. I am always having to guess whether you want to help, or you are just pointing a finger.

 

[vddobrev]

@pogo
Here:

 

[pogo]

See here: Link

 

[vddobrev]

See here: Link

But why?

 

[pogo]

To regain the unused headroom of 9dB and, in your case, to get back to a better volume matching.

 

[vddobrev]

To regain the unused headroom of 9dB and, in your case, to get back to a better volume level.

I don't have a poor volume level, in fact it is way too loud. By default, the digital in (Coax 1 etc.) is some 6dB louder than Line 1 direct without any Dirac involved. I don't feel I have the need to regain, but attenuate.

As it stand, Dirac filter on Coax 1 has no major effect on volume, but Line 1 direct is way too loud.

My question is: whatever Dirac does, why does it not stay in the digital domain, why is Line 1 direct affected?

All I know with my NAD T778 (I paid $99 for full Dirac licence) I don't have such problems, and I do have analgue direct there too for my CD player. No major differences in volume.

Edit: And why do I need to edit files, this is a paid software, it should be taking care of all this... is it NAD's fault or Dirac's fault?

 

[pogo]

My question is: whatever Dirac does, why does it not stay in the digital domain, why is Line 1 direct affected?

Again, DL does not affect the analog domain (see also post #1065). The difference in volume comes from the unused DL headroom in the digital domain.

 

[vddobrev]

Again, DL does not affect the analog domain (see also post #1065). The difference in volume comes from the unused DL headroom in the digital domain.

OK, but it actually does in practice. I should not have to deactivate Dirac filter manually when switching to Analogue direct, it should be handled by either Dirac or NAD, automatically.

So this is yet another bug, is it not? The unused DL headroom in the digital domain is not my concern, all I want is to switch to Analogue direct. And as per the NAD literature, this is a pure-path untouched signal. Why are we even discussing the digital domain, when we are in the pure analogue?

Edit - Quote from NAD M66 manual:

With “Analog Direct” enabled, analog input signal will bypass all digital signal processing (Tone
Controls, Dirac, Bass Management, etc.). The Balanced input will remain balanced all the way through to the Balanced output. The unbalanced inputs (phono MM/MC, Line 1,2) are converted to balanced right at the input.

 

[Nocko!]

Edit: Not to pulute this thread, we can move to private messages, as I am very interested in getting a refund from NAD.

I am short on time the next days, but of course I am here to help. Can you send me a private message or how does it work?

On the other hand: I have nothing to hide - perhaps a few others here can decide if we should go into private or if it does make sense to discuss the TCP/IP problem here. I still think that a device should fulfill what is advertised by the manufacturers, even if this is not about sound quality.

In a first step, you could present your experience with the RS232 port and TCP/IP to your dealer and ask him to "repair" this. And to be fair, you could show him the email from the MAD support I copied here.

And by the way: I can't prove it but I think there is no clean "analogue direct input or passthrough"... so I am amused to read the dispute with pogo...
Nocko!

 

[pogo]

if it does make sense to discuss the TCP/IP problem here

Yes.

 

[pogo]

I think there is no clean "analogue direct input or passthrough"

Are you questioning the block diagram from post #1065?

 

[pogo]

Why are we even discussing the digital domain, when we are in the pure analogue?

Because your unused headroom under Dirac Live causes the volume difference when switching to Analogue Direct in your case.