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


Hello,
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)
128x128miglos
"All competently-designed DACs will sound alike"".

DACS come in many sonic flavors. . . some may not hear the differences,
though. 

I don't think you can hear a difference...I think they more or less all sound the same....but true Audiophiles will tell me ,I know nothing....stop listening with ur mind....listen with your ears and enjoy...
If there ha been progress in DAC technology in the last few years, it hs been in the quality of clocking and the implementation of I2s or USB ports. The basic chips or ladder designs are maature. That said, significant progress in these 2 areas has material benefits. A well designed asynchronous USB port with high quality clocking (whether OCXO or Rubidium) through the slaving of the server/player is clearly superior to synchronous implementations of yore.