I've heard a few TDA1543-based NOS DACs, not sure if any were 47Labs clones. Once I got used to the lack of false detail with them I came to appreciate their timbral accuracy vs other DACs I had at the time which were delta-sigma types. However they did lack air and the bass was a bit soggy.
Or in plain English: awful bass and no highs. 🙂 Tbh i did not enjoy the lack of detail, false or otherwise, either. Nor the prominent upper mid.
Ancient memories from before when digital became listenable. As most other misunderstandings in audio this one also received a cult following.
The whole thing. It doesn't stand comparison with some of the more thought out designs.
The more complicated a dac is, the more they can screw up! The dac in question satisfies all of my basic engineering goals.
That may've been your impression, mine differs. The HF is rolled off by virtue of NOS droop but the lack of air wasn't down to that. Bass can be improved with a few external transistors acting as CCSs I found incidentally.
Prominent upper mid in my experience is down to lack of filtering of images, this applies to any and all NOS DACs (including 1387) without a following anti-imaging filter.
I'll re-phrase my earlier remark then - the apparent lack of significant attenuation of the first and second set of images - those between 22.05k and 88k2.