NAD M2

[richidoo]

New from NAD is a true digital amplifier. Digital signal in, DSP then PWM straight to output stage, filter then loudspeaker. Digital feedback surrounds output stage ala Spectron. 2x250W, 2 analog inputs. Distortion is extremely low, usable dynamic range is extremely high.

http://nadelectronics.com/products/masters-series/M2-Direct-Digital-Amplifier

It will be reviewed by Bob Harley in TAS in the December issue.  Preview:

I thought I posted about this already, but search didn't show it.

[JLM]

This is one of those, "Why didn't anyone think of this before?" kind of products.

[Carlman]

Sounds similar to a Tact 2150 integrated... great idea... More people have heard of NAD, so might be a big hit.

[richidoo]

might be a big hit.

Especially if it sounds good!

[_Scotty_]

richidoo, The M2 looks promising,I was reading through the online blurb and the amplifier uses a novel approach to implementing negative feedback that on the face of it should be pretty effective. I would like to see the amp double it's output into 4 ohms but the transformer size to do this probably got axed to hit a price point. At a MSRP of $5,999 US I am a little disappointed by it's performance into lower impedance loads. If I pay this much money I am going to a little power mad as well. I didn't think the TACT products utilized negative feedback and this may another place be where the core technologies differ from one another. Here is a link to the Zetex PDF doc on DDFA feedback. 
http://www.diodes.com/zetex/_pdfs/literature/pdf/SCCLZBR2.pdf
Scotty

[Bob in St. Louis]

What's the bottom line?

Also, 250 watts sounds cool, but really....

Bob

[richidoo]

Scotty, thanks for the zetex link. I will enjoy reading that.   
Supposedly the Spectron amp has digital feedback around the output filter (and optionally around speaker wires too.) I liked the presence and excitement of that amp, but a little NAD politeness would be welcome. My speakers are an easy load, min 4ohms at 200Hz, rising steeply below that and mostly flat above so this would be plenty enough current for me. Harley will test them on Wilson X2, which is an exceptionally easy load. 

Bob,
The bottom line:

[Bob in St. Louis]

The pic doesn't work Rich. 

[richidoo]

Bummer!  You don't know what you're missin! 

Try this
http://www.perplexion.com/the%20bottom%20line%202004%20-%20full%20bottom%20line.jpg

[Bob in St. Louis]

Hmm....Interesting.
At first glance the numbers look good, but on closer inspection the "distortion" appears to be greater than the tale the numbers tell.

Fucker.

Nevermind. 

Bob

[richidoo]

TAS review is out. Robert Harley gives it a good review. Says the DAC is not as resolving or refined as his Berkeley Alpha Pass class A reference electronics. The rebuttal comments from NAD suggest he may not have had the thing configured correctly with input sampling rate, etc. He's not an idiot so I  would be surprised if he had not tried every possible combination to find the best settings for his rig.

He said it was a little midrange centric, making it very involving and only occasionally a little too present when the recordings pushed it too far up front.

Plenty of power and excellent bass control and articulation. Internal master clock removes all jitter. No commets about the volume control scheme, but they did mention that the minimum word depth through the amp is 35bits.

Overall a good review. I would like to hear this one sometime.
Rich

[JLM]

Here's a link to the aforementioned review:

http://www.avguide.com/review/nad-m2-direct-digital-amplifier-tas-198?src=Playback

Overall a very positive review.  All comparisons done versus equipment that combined cost 10 times as much.  Harley could not imagine anything in its price range being competitive.

Newer (10 years) technology than Tact, in fact all analog stages have been eliminated.

Distortion figures explained in terms of the typical multiplicative effects through the signal path from DAC forward.  In comparison to conventional analog processing methods, this unit is roughly 35 dB quieter than the very best.

[richidoo]

John Atkinson reviews it in current Stereophile. Very favorably. He was expecting another class D dog but was surprised to enjoy it so much.  Review is not posted online yet.

[BobM]

A few of us heard this around Christmas time. It really didn't have a digital signature, and I'm kind of susceptable to that. It's like ants crawling up my spine when I hear a class D amp, but I didn't hear it on this.

It was pretty dry and clinical though, with good detail, but little in the way of ambiance and soundstaging. Rather flat overall. Not in the least romantic. However it was decent enough for me to think it will be a hit with the NAD lovers crowd. I'm also guess its size is determined more by the number and type of connections ont he back than by the amplification circuitry inside.

The digital conversion in the unit was just OK when using a direct digital output from a very good CD player. When we hooked up a very good CD player to it using the analogue inputs it did sound better (even though the analogue inputs are then converted back to digital in the NAD itself).

[hometheaterdoc]

I hated the CES demo of this with the PSB Synchrony Ones... the room was no hell, that's for sure... but the sound was very dry, clinical, lean, and had too much zip in the middle.  Soundstage was extremely short both in the vertical and depth department.  stuff was strapped to the speakers themselves instead of letting them disappear.  I know it isn't the speakers.  So it's got to be the room combined with the unit itself.  I really wanted to like this and specifically sought it out at CES to have a listen.  I was very disappointed.