In fact the only reason we have developed a TAS bridge for HQPlayer is because we have a group of customers owning a Chord Dave.
For this we are "extreme"-ly grateful!
Every DAC, especially at the high-end, has a very specific architecture, so achieving the best SQ comes down to optimizing the stream that the Extreme sends to it. This is one of the great strengths of TAS, as Emile & co. have sweated the details of determining exactly the right parameters required — buffer size, packet size, bit depth, etc — for each DAC their customers use.
With the DAVE in particular, and recent Chord DACs in general, enough is known about the internal architecture pipeline, thanks to Rob Watts' generous sharing of knowledge on other forums and seminars, to understand that the entire first stage of the pipeline (called WTA1) can be bypassed by supplying a 16FS sample rate (705.6/768) at the input. This is exactly what the external upsampler, the M-Scaler, does. Alternately, one can use a real-time software upsampler like HQPlayer to achieve almost, but not quite, the same SQ.
As
@romaz alluded to in his review of the TAS Alpha (see below), some of us are playing with an alternate method of pre-upsampling to 32/16FS, and this is where we are hearing the best results, especially with the DAVE. PM me or
@romaz for questions.
These pre-upsampled 32/705.6 or 32/768 files just need to be played bit-perfectly, and this is where we discovered that the combo of HQP and NAA (tuned by Emile with appropriate CPU and storage affinity) has outstanding SQ even when HQP is being used just as a player — i.e. without any of its filtering and noise shaping options (both set to None).
However, this again puts us in a Roon-like situation, where we are dependent on a 3rd party tool and a developer who doesn't share our priorities with regard to sound quality. For example, the recent HQP 4.90 release delivered a nice SQ boost, which then degraded again due to functional fixes in 4.92. Sound familiar to the Roon saga?!
This is where we DAVE alpha participants are actively helping Emile and team with feedback, as our goal is to get TAS+XD to outperform the HQP/NAA solution. This will put control of the software in their hands, and we trust them to address our SQ and functional needs far better than any 3rd party.
We are getting close, and I have full confidence in the team to get us there!
my method of local file playback is unique and consequently, Qobuz streaming will never quite equal local file playback. The following is a screen capture of playback of one of my reference files through Qobuz. Notice the playback streaming bit rate of 750kb/s of this Redbook file at the bottom.
View attachment 71815
Here is playback of that same track on TAS from the Extreme's local storage but note the massively increased bit rate:
View attachment 71816
The gap in bit rates is like comparing hi-res to mp3 and it sounds like it, too. Obviously, this file has been manipulated but plays back bit-perfect on TAS and sounds simply STUNNING on the Chord DAVE. This has absolutely nothing to do with HQP btw and unfortunately, seems to benefit mainly Chord DACs. If you have a Chord DAVE and an Extreme, feel free to PM me and I can share with you a file that you can listen to on TAS with your Extreme and your DAVE. This is just crazy good. If you have a Chord DAVE and don't have an Extreme, you really need to get an Extreme.