After Bennet/Dtmer Hk's comment on this previous post, I thought it might be interesting to revisit my longtime friend, the TEAC UD-501 DAC that I bought new when it came out in 2013. My preview and measurements (Part 2 PCM, Part 3 DSD) are still online of course.
I still remember doing those measurements in my previous home - it feels so long ago! ;-)
These days with the E1DA Cosmos ADC and RME ADI-2 Pro FS available for measurements, let's take a trip down memory lane at what has been over the years a reference DAC for me. I think the TEAC UD-501 is a special device that ushered in for many audiophiles a cost-effective, high resolution, well-built, reliable, low jitter, asynchronous USB audio interface which I suspect has influenced the design and performance of other DACs over the years.
Spec-wise, it was one of the first to catch my interest with the ability to handle PCM 384kHz and DSD128. The high quality metal case looks serious. It's based on a dual-mono TI/Burr-Brown PCM1795 configuration with dual toroidal linear power supplies. There are a number of PCM and DSD filters including the ability to turn off the 8x oversampling and allow "NOS" (Non-OverSampling) mode. The quad JRC MUSES8920 opamps they used were also another "feature" talking point back then. (Quite a complete specs page here for the TEAC.)