Are "vintage" DAC's worthwhile, or is this a tech that does not age well

@minorl You can always put a USB to SPDIF converter between your Aurender and DAC. That’s what I do after my computer. My DAC only has BNC input.

@minorl 

you make a very important point: the analogue section of a dac is actually a preamp. In most cases a simple attenuator will suffice to regulate volume to the power amp. Ideally therefore, the manufacturer of the dac should include analogue rather than digital lossy attenuation. 

This might lead one to conclude that rather than endlessly speculate on delta-sigma vs R2R technologies as well as the merits of various DAC chips, more focus should go to the quality of the analogue stage. 

It would be very interesting to analyse DACs with a digital out via a reference preamp vs their own analogue stage. While one would still have to speculate about the implementation quality of the digital out- and inputs as well as the cable, it would become a very worthwhile route to better focus on the analogue stage, which after all is the source of most RFI/EMI as well as ground level distortions in dacs.

@tomic601, Hi Tom, may I assume you own or have owned the 'Pandora' and if so what did you upgrade from and have you ever heard the Mojo Mystique kit. The superseded V3 interests me at about 50% the cost of pandora. 

i would think any over priced DAC Would still sound better than a  under
$1 K.  DAC  of today , 4/2021         NO!

Classic Statement , 
  In controlled A/B tests nobody can distinguish a $100 DAC from a $1000+ one. Try a PeachTree DAC It.  to a  low priced Schite Audio DAC   many examples Borris,  listen to a Audio Quest Dragon Dac to a  Small Beater 
And a Good day to you Sir