Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Preouts and the WM8740 D/A chip questions
#1
Hello,

I had a question about the preouts of the Devialet pro models. 

I understand the magic of the Devialet is experienced best through the speaker outs, as the entire chain from dac to amp is integrated and optimised for this.

In that case, it sounds like one might be making some sacrifices by using the preouts. Also in the preout specs for the Devialet pro 130, it mentions a "WM8740 D/A convertor operating at 24 bits/192 kHz" which is confusing because the main system already uses a much more superior PCM1792 dac chip.

So my questions are:

1) In technical terms, exactly what sound quality compromises are being made when using the pre-outs? Is it just not having access to SAM? Or are there more things that we give up?
2) What exactly is this WM8740 D/A convertor supposed to be doing with respect to the preouts?
3) When using preouts with digital inputs, is my digital audio signal being converted to analog by the superior PCM1792 or the more inferior WM8740?
4) Has anyone done any actual testing and have any quantitative or qualitative comparisons of the differences between speaker out and preout?

Thanks!
Reply
#2
There is a big degradation in the sound quality when using the Devialet 200 Pre-Out. It would be better to just use a separate £400 DAC instead, which would sound much better. I don't understand why Devialet even provides the facility for a fixed stereo pre-out, as it sounds awful. This is a real limitation of the hardware and in my opinion Devialet should provide a decent DAC for the pre-out which should be equivalent to the sound quality when compared with the speaker terminal out.
Reply
#3
I have not heard the pre outs to be fair but I always felt the true "devialet" sound was in large part related to the the ADH amplification stage . . Perhaps the 1792 chip can only be used with the ADH stage and another dac is needed for the preouts - the dsp magic including Sam I'm sure plays an big part as well  . . But it's the ADH stage that always seemed the most unique part of the devialet package to me

Just my 2c
Roon/mac mini > hqplayer > sms-200 ultra and MC-3+ USB both clocked via Mutec Ref 10 > MIT Oracle MA-X AES/EBU > D440 > Dynaudio C1 MkII via MIT Matrix HD-60
Reply
#4
Is this any different in the Pro series?   I just started using the Preouts of my 440 Pro to my Senn 650 headphones and, to be honest, have been a bit underwhelmed by SQ or lack thereof.    I wonder if the new OS/streaming board will come into play at all.
Devialet 440 Pro (two 220s)- Oracle CD transport - Kuzma Stabi S/Stogi S turntable - Von Schweikert VR-35 speakers - JPS SC3 SCs - PI Audio power conditioning -
Triode Wire Labs ICs and PCs - Roon on NUC 8i7beh running ROCK
Durham, NC USA
Reply
#5
It might be worth bearing in mind that the pre-out is probably not intended to drive headphones - it might have too high an output impedance to do justice to that job, depending on your headphones.
Roon (Mac Mini), Wilson Benesch Full Circle, Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)