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
DAC chips age well, in fact many of the best DACs made today employ old chips. My personal favorite is the CAD 1543 MK ii which uses 16 of the old Philips 1543 chips. 
Advances in understanding of power supply isolation, usb integration, and EMI/RFI, mean that new DACs using the old chips is often the sweet spot. 
I have also heard dacs sound different from each other. I even had an old dac upgraded and it became much better.

Regarding the question I would guess that something like a ML dac that was very advanced for its time still sounds good. Maybe not as good as the latest equally advanced and expensive dacs. If you can get it for a good price it may be worth it.

On the other hands there are now dacs for $1k - $2k that are said to sound great. You would probably have to compare the old and the new next to each other to hear which is best and which one you like the best.

Here is an example of a somewhat affordable dac:
https://www.stereophile.com/content/okto-dac8-stereo-da-processor

If you for some reason don't trust Stereophile it also got a great review at ASR
https://www.audiosciencereview.com/forum/index.php?threads/okto-dac8-stereo-dac-review.14705/
Apart from ageing parts i do not see any reason for not sounding excellent in redbook. I bet a SFD2 can show a clean pair of heels and then some to modern dacs. And yes there is a big difference between a 5k to a 0,5k value dac.

G
Firmware Updates to CD/SACD/Blu-Ray players.

I typically update my camera's firmware, but for audio use of these?

I just bought a 2009 Oppo BDP-83SE (special edition, improved audio).

https://hometheaterreview.com/oppo-digital-bdp-83-universal-player-reviewed-1/

It has Firmware Updates, I suspect only for minor video issues. 

If all the initial reviews said very good audio, never found an audio 'problem' mentioned, why do/risk it?

Any recommendations?

thanks, Elliott
Why would it not age well? If you bought a cd player 10 years ago of good quality, it also contains a dac inside. If it still works, then what is the issue? Honestly, the only dac you need is the musical fidelity v90 dac. $299 and worth every penny. Sounds just as good as a $1000 dac. Small form factor, well designed, plenty of connection options, a burr brown chip, and it’s a stereophile class A component. To spend much much more on a dac is ridiculous. I've owned my v90 dac for 2 years now, it sounds wonderful. I use it in conjunction with both a Marantz hd cd1 cd player/transport, as well as with the audiolab cdt6000. I also have my grace digital internet radio connected to it, as well as my topping bc3 bluetooth module. Great versatility.