What's next for the test bench?? A slight deviation from plan, and I will tell you why. I happened to be perusing Amazon looking at various source components that I find interesting, and I came across the SMSL D300, which uses a Japanese chipset I have not yet heard of.. the ROHM BD34301EKV.
It caught my eye, because it appears to convert DSD via native analog FIR, and ONLY that way. No 'DSD processor' or 'DSD direct' to choose from. The block diagram seems to say it is ONLY DSD Direct. I also like what the data sheet has to say about the DSD FIR filters. It is very straightforward.
It is also a segment DAC. It doesn't say exactly what those segments are, but one of them must be a Delta Sigma segment. Which means the other is some kind of true PCM conversion, most likely. The diagram gives no indication of any but a Delta Sigma modulator for PCM, but since it does say its a segment DAC/filter then I would say its very likely all a thermometer code DAC with PCM'S msb's converted with a number of equally weighted switches that do indeed bypass the DS-modulator. Just a guess, though. If I am correct, then its very much like the Burr-Brown DACs developed in Japan before TI took ownership.
It arrives tomorrow, and testing will begin after after a 48 hour break-in over the weekend.
Can't wait to see how it compares to AKM and ESS based products at this $400 price point!