What is the average life expectancy of a DAC?

30 years is not too short a life span for a DAC.  There are a couple of thigns to consider though:
1 - DAC's after 2010 got much better, especially with RedBook playback so buy older models with caution.

2 - Streaming services and connectivity changes more rapidly than resolution and bit rates. 

Best,
E

jasonbourne52

Nobody can tell a $100 DAC from a $1000 DAC if they listen blindfolded

That’s an interesting claim. Please tell us about your listening tests that have led you to this conclusion.

Yes DACs should last many many years but technology moves ahead quickly especially like others have stated connectivity. Look for companies that constantly update products. My dac originally didn't have an Ethernet connection (wasn't even a thing many yrs ago) then streaming came out and had my dac updated to accept Ethernet.

Working, for ever, sounding good, for ever, feature wise much shorter. But i suspect they would  devaluate quicker than anything else. Of course there are exceptions for some keeping a good value and having only the very basic features.

G

@jjss49 I just read the stereophile review of the magic brick and they argue it works. I’m sure the tongue implanted in the cheek of the marketer who named this product is still lodged there! I’m not being snarky -- I do believe vibration control is a real thing -- but I have to laugh at your question. Now, combining your question with the one about Dacs, how long will a DAC last if you drop a magic brick on it? 

Oh, and the people named after movie superheroes (JB, e.g.) need to get their hands on a good DAC. I have zero trouble hearing my $1100 R2R Dac’s betterness (a word, right?) over both a $500 Peachtree and the NODE 2i Dac. I mean, come on JB, go snuff some bad guys, ok?