[Somnambulist]

Yep, it's your typical 1U rack mount size in terms of hifi/stereo... certainly not aimed at the desktop crowd. I made it work back when I first got it by having my monitor mounted on the wall rather than using a stand, but now it's in a hifi rack with all my full size stuff.

 

[danik97]

Hi all at Head-Fi happy new year,well ive been a very happy owner of Nad M51 for some time now and have to say it made up my mind to go completely digital with my music,squeezebox touch is great but doesn't do m51 justice so ive been on lookout for better source,my prefered imput on m51 is HDMI so needed something with quality that could output HDMI,week before xmas my Oppo 103 arrived and have to say this is one amazing piece of equipment,sound from m51 is another level,well worth investment,plus as far as picture quality goes there has been a massive improvement there also,oppo has hdmi imput also so have youview box been upscaled by oppo and results are exellent,the oppo network features are greatly improved from previous models and work very well,i treated myself to a new nas synology diskstation ds712+ with 6tb of storage to feed my all digital setup and have to say its fantastic all controlled with apps from my nexus 7 very happy and if anyone has any questions about any of the products ive mentioned i will try to answer,thats my wish list for 2012 complete time to get back to work as bank balance has taken a hit this xmas

Can you compare sound between NAD's USB and OPPO's coaxial output? How OPPO sounding better?

 

[Jacky5555]

Hi,
I've been with a m51 for a month.
I'm happy with the sound: open, spacious soundstage, detailed but smooth sound, the timbre is neutral, voice is natural (a little thin), bass is not realy deep but fast and detailed.
However, I found a problem of the preamp, at the volome > 3db the sound become noisy with pops and cracks,..  noticablly.  Even the input was either usb or hdmi or coaxial (from a oppo 95 or mac mini+ AP2) it happened. At volume <=0db, the sound is still clean with black dead background.
Then I talked to a dealer of Nad, they explained it a common issue of M51 (they tested many).
But I don't agree so.
Anyone here ever try the preamp loud enough (volume>3db) to test the issue?
Other than this issue, I'm totally satisfied with the sound quality.
Mine is the latest firmware 1.41.

 

[Clemmaster]

You're amplifying the signal in the digital domain: there's no guarantee you won't clip the signal by doing so.
The same can happen when upsampling the signal (overshoot).

I read some experience issues at 0dB: this, however, is not normal.

 

[Stormfriend]

I believe 1.41 includes a change to avoid clipping at 0db, but anything above that may have issues.  I use the M51 strictly as a passive preamp so I don't use it to boost the signal.  When I first took it out of the box I think it was on +10db or something, which clipped horribly.
 

 

[Cante Ista]

I had this issue but it went away after a while. I dont know how long it was there bc I dont normally listen that loud. I heard it first day I got it and then did not worry and just listened at my levels. Sometime later I checked it just out of curiosity and it was gone. 
Quote:

Hi,
I've been with a m51 for a month.
I'm happy with the sound: open, spacious soundstage, detailed but smooth sound, the timbre is neutral, voice is natural (a little thin), bass is not realy deep but fast and detailed.
However, I found a problem of the preamp, at the volome > 3db the sound become noisy with pops and cracks,..  noticablly.  Even the input was either usb or hdmi or coaxial (from a oppo 95 or mac mini+ AP2) it happened. At volume <=0db, the sound is still clean with black dead background.
Then I talked to a dealer of Nad, they explained it a common issue of M51 (they tested many).
But I don't agree so.
Anyone here ever try the preamp loud enough (volume>3db) to test the issue?
Other than this issue, I'm totally satisfied with the sound quality.
Mine is the latest firmware 1.41.

 

[woodcans]

I can't get near 0dB with system, it would be way too loud. And I like to turn it up. I am still on FW 1.39. Has anyone upgraded and noticed any improvements and/or ill effects?

 

[olor1n]

Yeah, 0dB is too hot. I usually adjust between -24 to -15dB so I have some travel on my amp's volume dial. I read elsewhere that the clipping issue at 0dB was resolved in firmware prior to 1.39. The big thread over at stereo.net.au has a change log. Many there also agree 1.39 is the best firmware in terms of sq.

 

[Jacky5555]

Thank you all, at least now i'm no worry for the deffective issue. -)
So it seems 0db is limit of the m51 up to now.
I had no idea before about the range of m51's volume which is from -90 to 10db, meaning 0db should be too hot.

 

[Cante Ista]

I feel kind of dumb for asking this so please be kind, but 
1) where do I get updates for my m51?
2) how do I check what FW/SW my m51 is running? 
 
 
I am in the US, if that makes a difference. 
 
Thanks!

 

[paradoxper]

Quote:

I feel kind of dumb for asking this so please be kind, but 
1) where do I get updates for my m51?
2) how do I check what FW/SW my m51 is running? 
 
 
I am in the US, if that makes a difference. 
 
Thanks!

Link 1.41
 
As for checking FW, I can only find the guide via basically having you reset your FW.
 
 
Press and hold front panel [INPUT] button.
2 Set to ON the rear panel POWER switch while still holding on to [INPUT] button.
3 VFD illuminates. Release [INPUT] button. VFD will show
 
 
Within 3 seconds, press front panel Standby button and “RESET” will now flash.
5 M51 will go to reset mode with the VFD showing “Factory Reset

 

[woodcans]

Quote:

I feel kind of dumb for asking this so please be kind, but 
1) where do I get updates for my m51?
2) how do I check what FW/SW my m51 is running? 
 
 
I am in the US, if that makes a difference. 
 
Thanks!

 
 I asked the same question and a fellow head-fier emailed me the FW. (PM me if you want it, I have 1.39). NAD might email it to you if you contact them.

 

[Lonely_Rider]

Quote:

Yeah, 0dB is too hot. I usually adjust between -24 to -15dB so I have some travel on my amp's volume dial. I read elsewhere that the clipping issue at 0dB was resolved in firmware prior to 1.39. The big thread over at stereo.net.au has a change log. Many there also agree 1.39 is the best firmware in terms of sq.

 
I asked from NAD customer support about sonical differencies between fw-versions and answer was:
 
"We cannot disclose the improvements between the M51 firmware versions."

 

[The Monkey]

I'll see if my contact can shed some light.

 

[Cante Ista]

thank you all for your responses!!! 
 
@ The Monkey - I would really appreciate you posting your NAD contact response.