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Can you help pinpoint why I am now satisfied with my digital setup?

Why ask why?  Bud dry. Right?  Why ask if you are satisfied? Just be. Here goes....

I put out a thread recently how I couldn't get my digital to sound good enough to listen for hours on end.  It sounded great, but nowhere close to my analog front end. Many users recommended I might try an R2R DAC.  While researching those and other solutions, I did the following: 

Instead of feeding my Primaluna integrated with the NAD M51 DAC, I ran the NAD M51 analog out in XLR/balanced to a Schitt Freya, then I ran single ended RCA out from the Schitt to the Primaluna.  I turned the Schitt preamp volume attenuator to its maximum.  Voila!  Well, maybe not equal to my vinyl front end, but I can now listen for way longer periods. 

The NAD M51 is not what you'd call an overbearing DAC sound.  I'd say it's neutral to the warm side of neutral.  

I thought the short answer was the improvement is because I'm adding a tube buffer, vis-à-vis the Schitt Freya, to the DAC output signal.  But, wasn't I buffering the signal before when I fed the NAD DAC to the Primaluna?  Is the improvement due to tubes on tubes (Freya on Primaluna)?  

I also note that in the summer when I ran the NAD M51 into the Freya driving an NAD M22 amp I felt nearly the same as I did running the NAD into the Primaluna.  Is this just tubes on tubes?  I see no other explanation.  

I'm a bit fussy so I've been hesitant to say this solved the problem without extensive listening.  But now that I'm a week in to this setup, I find it works and think that will remain my long term view.  



128x128jbhiller
audioengr
3,282 posts
 

The Shiit preamp has lower output impedance than the NAD DAC going directly to your Prima Luna integrated.  It is like having a buffer, either SS or tube to get more current drive to your integrated.  The NAD alone runs out of gas as far as the Prima Luna is concerned.

This is not uncommon.  Most DAC's have 50-100 ohms output impedance.

If you use a really low capacitance interconnects, like the ones that I used to make (3.9pF/foot), then this is less of a problem, however some amps just need more current to sound good.

Steve N.

Empirical Audio

jbhiller's avatar
jbhiller OP
1,445 posts
 
Steve N. Thank you!!!!  That makes sense.  I really appreciate the technical explanation.
roxy54's avatar
roxy54
8,104 posts
 
It sounds like you made things better, but I think that yiu won't know what you're missing until you try an r2r. Tube buffers are just a band aid.
georgehifi's avatar
georgehifi
10,312 posts
 
The Shiit preamp has lower output impedance than the NAD DAC going directly to your Prima Luna integrated.
Your saying the: 
Nad M51 with (4.7v xlr) (2.4v se) output at 180ohm output impedance, is not a great match into the PL integrated at 100kohm input impedance that only needs only 0.36v input for full wattage output??

And as far as the cable capacitance goes, even if they were 100pF per ft at 2mts 600pF this with the 180ohm output of the M51 is still only -3dB at 147khz!! hardly what I call rolling off the highs!! Stop selling your cables!

Please give your electronic math reasoning behind both of these?? I’m very intrigued!

Cheers George
mahler123
3,446 posts
 
OP
  I think that you need to ask yourself what the goal is.  In your last thread I got the feeling that  what I would consider a digital sound is not your cup of tea, and that you preferred something that reminded you more of your analog system.  To me it seems that a tube based system and perhaps an older type of DAC sound might be the key.  I would consider a Border Patrol DAC, which uses an ancient DAC chip with a newer implementation, and whatever tubed electronics that work well with your speakers
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