New vs. old DACs - opinions?

I think the basic issue is a clock is needed to convert the bits to analog at the right time otherwise the result is jitter and this typically occurs at the other end of the wire from the DAC, back at the source which feeds the DAC. Both clock and connection then come into play in regards to converting the right bits at the right time. If the DAC resamples and reclocks, then the the clocking function and DAC are more tightly integrated within the DAC and there is less to go wrong.

Kijanki, I'm right there with you on opamps being so much improved . . . thinking back to the "bad old days" of slow all-NPN types like the 741 just about makes my stomach churn. And I'm pretty amazed about the quality of diverse types of devices - i.e. high-quality JFETS and complimentary bipolars sharing the same wafer? Something we wouldn't have thought possible a few decades ago.

But an opamp example that would fit the example I gave above (for DACs) are those modern CMOS devices with an onboard DAC for trimming? Yes, their offset specs are impressive, especially so for inexpensive devices . . . but they're irrevelant for perfectionist audio. Ditto for rail-to-rail input and output capability, ultra-low quescient current, and single-supply "precision" operation.

Fortunately, in the world of opamps, it does seem that the bouquet of ultra-high-quality products available is more extensive than ever . . . but the fact that the attributes of most concern to most IC manufacturers (or at least the ones they spill the most ink over) aren't ones that matter most to high-end audio . . . is worth taking notice of.

Kirkus - You said it right. It is very sad that we don't represent any buying power.

Just bought a ARC DAC5 back from 1995. I've had all sorts of newer DACs including a PS Audio nuwave, the NAD M51 and many others. This old ARC absolutely kills the newer ones. So rich sounding and 3D. I'm hearing layers in songs I've never heard before. I had to buy a USB to SPDIF converter to use my Mac Mini with it since the old ARC doesn't have USB. I'm done playing around with newer DACs. 

With so many quality USB/SPDIF converters on the used market, there are many options for taking advantage of older DACs. Many have far better power supplies and analog output staged than many of the newer ones, especially at the lower price points that the older DACs can be had for. Like with newer ones, the older ones sound different from each other so system matching remains important.