How old is too old for a Dac?

I believe that for redbook CD playback via transport or as uncompressed files from computer or server, use of an older DAC with an excellent power supply and analog output stage at a fraction of original cost seems appealing to me. Of course, with the computer use of a USB/SPDIF converter would be required.  I am about to try a used Bel Canto DAC2 in my secondary system.  Currently use a Bryston BDA-1 in my primary. 

As Bigkidz stated, considering DSD digital is different. 

I set a budget and look for a DAC that is used, however 3-5 years old. I believe I can purchase a better built DAC that way. Better power supply and analog output stage being a priority. I am a fan of external USB/SPDIF conversion so USB implementation is not an issue.

I have put to use a couple older DACs purchased in the last week:

A Audio Alchemy DAC-in-the-Box (~1994 model, $75) which I am using in the living room low budget system to augment audio from inexpensive BR players for Video. Works fine considering its age and am sure it helped smooth the sonics coming from many of the early model DACs sold in the 80s.

A Bel Canto DAC2 ( ~2004 model, $275) which I compared to a Schiit Bifrost Uber (2013 model, $225) in my second system consisting of a NAD236BEE driving B&W 685s via Audioquest cables. The Schiit won out for me in that system, having a less analytical sound probably due to greater 'digital bloom' from the DAC2 on some aggressive rock CDs. I did like the DAC2 when driving my Schiit Vahalla tube headphone amp. Seems to make for a more lively presentation. However, in truth I haven't spent enough time to fully appreciate the differences between these DACs.

 

Great find redmosessc!  A lot of great older used DAcs available for one playing redbook cd files and owning a good USB/SPDIF converter. I currently own four non USB DACs and two converters.