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

@runkster, 
Your "humble opinion" is on the mark in my opinion 😊. For some reason the crucial analogue output stage is frequently overlooked and downplayed. Conversely the DAC chips are over credited in determining sound quality.  

I'm not surprised that the older PS Audio Ultealink sounds better than the Schitt Modi, Not at all. I'd bet the  Ultealink very likely has better quality  analogue output stage and power supply. 
Charles 

I wouldn’t disqualify older DAC's, there are some fine DAC's that were made in the past.

However, you need to ask yourself some questions, such as: do you want DSD\MQA or maybe even Ethernet connection?

If your answer is yes to one of the above then you probably find the answer in newer DAC's

The big difference in DAC sound in the analog output, while you can argue that all DAC'S are doing the same (converting digital information) there are several methods for that which will affect the sounding, but the biggest sound different relay in the analog section which in the end is responsible for the signal that gets out of the DAC – and there, not all are created equal.

I worked in the audio industry in the mid 80s and had the opportunity to hear many of the early attempts at audiophile grade CD sound.  The results ranged from miserable to listenable, but in most cases a good FM receiver would have them licked.  It wasn't until the early 90s that CD players started to perform at a level I considered comparable to a good vinyl source. 

Back in the mid 2000s I was listening to a friend's audio system.  He had a pretty nice DAC (can't remember the name for reasons I will soon reveal) that cost several grand being driven by a pretty decent digital source.  I really liked the sound of that DAC and seriously thought about getting one, but there was no way I could afford it at the time.  

He also had a Sony DVP-S9000ES that had the added advantage of playing SACDs, a format that was still relatively new but held great promise.  We decided that I should do a blind test between his DAC and the Sony.  He picked out CDs and SACDs of the same music, being sure each had the same mastering.  When comparing the two using Miles Davis' Kind of Blue, one was clearly more realistic with an improved bass foundation and dynamic range.  I made the assumption that the better sounding unit was the DAC since it was an "audiophile" product made with better components and bla bla bla.  Of course I was wrong and I had actually preferred the Sony player.  From that day I was convinced that red book CD was limited sonically and that higher resolution formats were needed to go to that next level in sound. That lead me to completely forget about the DAC and to purchase a 9000ES along with as many SACDs as I could get my hands on, paying less paying less for the lot than that one DAC would have cost.  It still sounds great with CDs, but really shines with SACD.

Long story short, my advice would be to stick with a DAC built this millennia, but do as another poster suggested and buy a DAC that will allow you to play higher resolution formats.

Hi Telefunkin74

I'd be really curious to know if you did that test again what you'd find.

Another side effect I've found of modern DAC's' is that upsampling isn't that much of a benefit, but older DAC's consistently benefit from upsampling.

Don't get me wrong, there is a difference, but the difference is much more narrow, and in the very top octave. I can explain the benefits today by looking at the frequency response of 44.1/16 vs. 96/24 or higher. There's just a hint more air, sometimes hardness.

In older DAC's everything seemed better with high res signals. Bass, imaging, tonal complexity and the ability to play complex musical passages without becoming mushy.

@charles1dad You are so right about that and the guy I sold my Yamamoto Dac to raved over it so much I almost wanted it back ;) And yes analog output stages and power supplies are probably more important than the Dac chip and its implementation.