[olor1n]

 

  Reverted from 1.50 back to 1.39.
 
Yeah, this is the M51 I know and love.

Man you're lucky. I thought there were a few who went back and had that scramble the M51 up bad. I never heard 1.39 as I started at 1.41 before going to 1.50. Personally I certainly couldn't hear a difference between those firmware revisions. I'm assuming a great deal of the revisions is to solve smaller niche problems that arise as NAD gathers users feedback more than sound quality, but certainly I don't know for sure.

 
The documentation for 1.39 states that it is only recommended for units prior to s/n H25M51XXXXX. I've had my M51 for some years ( s/n H29M51XXXXX) and it came with 1.39 installed, so I knew (hoped) I wouldn't have trouble reverting back from 1.50.
 
I haven't heard the other firmware updates. I stayed on 1.39 for a long time as I was very content with the SQ and reports online that others also preferred 1.39 gave me no cause to upgrade. Stereophile did quote NAD as stating that there is no tweak to the M51's signature in firmware post 1.39 - other than a -1dB adjustment.
 
Initially, I did not regret the upgrade. In terms of voicing, nothing really jumped out as drastically different to what I was used to. After some time with 1.50 though, I noticed a slight lack of energy. The M51 seemed more polite and less engaging, and in the background, it became obvious that the lower regions were a touch less dynamic, affecting the presence and impact of bass and percussion instruments.
 
Increasing the M51's volume +1dB did not seem re-balance 1.50's signature to what I was used to hearing from 1.39, as that adjustment also raised the volume of the upper frequencies. This initially gave the impression that the presentation was perhaps a touch more neutral in this firmware, with a little more detail in the upper registers, but after reverting back to 1.39 it is evident that the M51 is not blunted in those regions.
 
After reverting back to 1.39 I played the same albums that I had just listened to and had found to be a touch flat and somewhat polite on 1.50. With my amp's stepped volume control set to the same setting and the M51's volume set -1dB less than where I had it - to accommodate for the documented difference between firmware revisions - I once again heard the same musically engaging character I was used to hearing from the M51.
 
 

 

  Reverted from 1.50 back to 1.39.
 
Yeah, this is the M51 I know and love.

 
Hello olor1n,
 
How did you revert it? Did you revert from 1.50 directly to 1.39 or 1.50 > 1.43 > 1.41 > 1.39?
 
Thanks 

 
I went from 1.39 (the original firmware on my unit) straight to 1.50. I managed to revert straight back. I've had no other firmware installed on this unit.
 
 
 
______________________________
 
edit: Firmware 1.39 is found in this post - http://www.head-fi.org/t/602771/nad-m51-direct-digital-dac-impressions/660#post_9140977. Proceed at your own risk.

 

[bimalh]

Does both the balanced and unbalanced outs have signal at the same time. I am thinking of buying one but I need two pairs of outs active at the same time. Thank You.

 

[T.R.A.N.C.E.]

^ Yes, I have two subs connected to single ended outputs and my monitors to the balanced outputs.

 

[jeffreyw311]

Where can I find firmware 1.39?  All file hosting links are dead and I can't find an archive on NAD's website.

 

[T.R.A.N.C.E.]

^ Just know that if your M51 came with firmware later than 1.42 then you can't even load 1.39.

 

[jeffreyw311]

  ^ Just know that if your M51 came with firmware later than 1.42 then you can't even load 1.39.

I read about that but I think I'm fine if that's the case since mine is running 1.41.
 
Edit: Just found the firmware in the post above arrrgggh.

 

[WDitters]

Mine came with 1.42 and I had already upgraded to 1.50 by the time I read this. I went back to 1.39 just for comparison sake and I have to agree with previous poster. 1.39 is more musically engaging for me due to fuller and more rounded lows ... I definitely intend to stay on this version for a while ...

 

[Sonic Defender]

I have never heard 1.39 so I think I'll avoid it as I don't want to know if it sounds better! I must admit I didn't hear any difference when going from 1.41 to 1.50. You guys sure have good audio memory, mine isn't that good for sure. Sad for me.

 

[WDitters]

You guys sure have good audio memory, mine isn't that good for sure. Sad for me.

.

Since an AB comparison is a bit hard with only one M51 I evaluated 1.39 versus 1.50 by comparing them to the built-in DAC of my Musical Fidelity A1008 amplifier (quality level XDAC v8)

I connected the M50 player via AES/EBU to the M51 and via SPDIF to the A1008 amplifier. The M51 itself sat connected via RCA to the A1008 amplifier... Both digital cables are DH labs Silversonic D-750 and D-110. RCA cables are Harmonic Technology Pro Silway II.

Upon comparing both revisions to the A1008 DAC I found the difference between the 1.39 and the A1008 simply staggering. The difference between 1.50 and the A1008 DAC was still there albeit less pronounced and in distinctly different areas. Mind you, even then the difference is big, but for me I preferred the more rounded sound of 1.39 to the more detailed but slightly more clinical 1.50... 1.39 also appeared to have a slightly wider soundstage... So I will hang on to 1.39 for now, until the next release

 

[Sonic Defender]

.

Since an AB comparison is a bit hard with only one M51 I evaluated 1.39 versus 1.50 by comparing them to the built-in DAC of my Musical Fidelity A1008 amplifier (quality level XDAC v8)

I connected the M50 player via AES/EBU to the M51 and via SPDIF to the A1008 amplifier. The M51 itself sat connected via RCA to the A1008 amplifier... Both digital cables are DH labs Silversonic D-750 and D-110. RCA cables are Harmonic Technology Pro Silway II.

Upon comparing both revisions to the A1008 DAC I found the difference between the 1.39 and the A1008 simply staggering. The difference between 1.50 and the A1008 DAC was still there albeit less pronounced and in distinctly different areas. Mind you, even then the difference is big, but for me I preferred the more rounded sound of 1.39 to the more detailed but slightly more clinical 1.50... 1.39 also appeared to have a slightly wider soundstage... So I will hang on to 1.39 for now, until the next release

Cool that you did this, but isn't audio memory still at play here? Perhaps I am misunderstanding you, but I believe you were still needing to do the firmware upgrade which takes time is that correct? Maybe I need to try installing 1.39, but I am worried about panning my M51 by going backwards which I have heard happens.

 

[KmanChu]

.

Since an AB comparison is a bit hard with only one M51 I evaluated 1.39 versus 1.50 by comparing them to the built-in DAC of my Musical Fidelity A1008 amplifier (quality level XDAC v8)

I connected the M50 player via AES/EBU to the M51 and via SPDIF to the A1008 amplifier. The M51 itself sat connected via RCA to the A1008 amplifier... Both digital cables are DH labs Silversonic D-750 and D-110. RCA cables are Harmonic Technology Pro Silway II.

Upon comparing both revisions to the A1008 DAC I found the difference between the 1.39 and the A1008 simply staggering. The difference between 1.50 and the A1008 DAC was still there albeit less pronounced and in distinctly different areas. Mind you, even then the difference is big, but for me I preferred the more rounded sound of 1.39 to the more detailed but slightly more clinical 1.50... 1.39 also appeared to have a slightly wider soundstage... So I will hang on to 1.39 for now, until the next release

 
How do you like the M50 player? I have been itching to try one but wonder about the functionality of the BluOS. Do you find it to work well?

 

[dreambass]

Seen this for £899 can anyone give me a comparison to the chord Hugo or Qute, also I'm using the fostex HP-A8 as dac and it's been my best dac, don't need an amp.

 

[WDitters]

How do you like the M50 player? I have been itching to try one but wonder about the functionality of the BluOS. Do you find it to work well?

The M50 is awesome, and by its OS immensely flexible. Of course its quality depends on the DAC it's paired with, but aside from that you can't go wrong with it. Currently supporting Deezer Qobuz Tidal and Spotify it will ultimately also support Apple Music and DSD streaming... For me this currently represents everything I always wanted from a high end streamer

 

[Spark85]

Hello all from Spain.
 
I found this post to seek information related to the DAC M51, that I have very recently.

Specifically I was looking for the firmware 1.39, but Link's I've seen about it, are fallen ¿Would I could help get it?
Currently I have version 1.50 and my NAD M51 have the serial number H48M51XXXX
¿ You believe that I could get into trouble, if I upgrade to such an ancient version with my DAC?
 
Thank you for help.

 

[Sonic Defender]

  Hello all from Spain.
 
I found this post to seek information related to the DAC M51, that I have very recently.

Specifically I was looking for the firmware 1.39, but Link's I've seen about it, are fallen ¿Would I could help get it?
Currently I have version 1.50 and my NAD M51 have the serial number H48M51XXXX
¿ You believe that I could get into trouble, if I upgrade to such an ancient version with my DAC?
 
Thank you for help.

There were a few posts from M51 owners who had a technical issue with their DAC after down-grading the firmware version. I'm not sure I would take the chance myself. Sure, you may hear from 10 people here who have downgraded and it wasn't a problem, but a few did have an issue. I guess it depends how lucky you feel and whether or not you have confidence that the reports of 1.39 sounding substantially better are completely accurate. It is possible that inaccurate audio memory might explain some of the perceived differences and in the absence of controlled, blind listening testing you can't rule that out as an explanation. I am not saying it is a fact, but you should at least consider that it is possible.