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

whether it’s worth looking into old dac such as
Spectral SDR 2000,
Mark Levinson No.35 (36)
or so Sonic Frontiers Sfd-2 Mk2 DAC.

Digital audio is the fasted moving, now improving category out there
Because to this day they have no usb connection or other options.
But is it necessary?
Or is it better to still focus on a truly time-tested sound?

(sorry for my English)
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 

What dac you have that uses the 1543 chip?
I wish I never threw away my casette tapes😃

What dac you have that uses the 1543 chip?
A french dac  with an internal battery,a NOS one, designed by Christophe Mariac, bought on EBAY... Starting point systems dac....

Look for one used anything below 200 bucks will be the right price...