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.  



jbhiller
Post removed 
Those are sage words Elizabeth!

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

Steve N. Thank you!!!!  That makes sense.  I really appreciate the technical explanation.
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.
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
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
I reread your OP again...I had thought that it was going to be a repeat of your earlier complaint.  So are you in a good spot now, or are you still evaluating?
Nothing like the sound of a diamond tracing a spiral groove in a rotating plastic disk! Those minute undulations are present in the groove walls and are "read" at the molecular level by the stylus! So resolution is theoretically greater than any digital system!
You're (not 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??

That is what I'm saying. The 10K input impedance is just a resistor.  Has everything  to do with the dynamic response of the active input device, a tube in this case. This is where more drive current is needed.  It's the input impedance of the tube circuit that is important here, not the resistor.  Dynamic response is a different animal than steady-state, which is your .36V sensitivity spec.

Steve N.

Empirical Audio

@mahler123, Yes, my objective was to push my digital front end up a bit (better it so I could listen longer).  The reason I want to do that is I really like exploring the catalog on Tidal before I buy vinyl, which I'm not yet familiar.  Some have said I should just stick with vinyl but that misses the objective--I cannot just buy records to no end.  I have to lay out the cash and just as important I have to store them.  I don't want a 10,000 album collection.  I like to listen to each album in my collection. 

So I think the situation is much much better with the Freya feeding the Primaluna with my DAC feed than the DAC direct to the Primaluna.  But, and it's a big BUT, this sounds better, not ideal.  I can live with it.  

I spent hours last night comparing the best recordings I could find digitally that are also in my vinyl collection, with the criteria that they had to be favorites or recordings I really like and knew very well.  Vinyl won out. 

Tonight I'm listening to digital because I'm exhausted and don't have much time.  I had my kid all day and the wife is doing bed time, so I wanted to keep it simple and just listen and not have to get up much to deal with records.  Well, digital is fine, just not as engaging. 

The holographic picture I get with vinyl and my cart/preamp is just intoxicating when things are right.  

That is what I'm saying. The 10K input impedance is just a resistor. Has everything  to do with the dynamic response of the active input device, a tube in this case. This is where more drive current is needed. It's the input impedance of the tube circuit that is important here, not the resistor. Dynamic response is a different animal than steady-state, which is your .36V sensitivity spec.

Steve N.

Empirical Audio

You have not address my questions just briefly skirted around one of them.

This is what you said was the reason the Schiit was better than going direct, and I called you on it. As none are at any disadvantage impedance wise going into the 100kohm input impedance of the Prima Luna.
 
 " The Shiit preamp has lower output impedance than the NAD DAC going directly to your Prima Luna integrated."
This is not correct!

And as for the interconnect capacitance you quoted, way out there in voodoo land I'm afraid as I proved with the math.

Cheers George