I have an odd problem. (hah hah) When I connect a Fostex HP-A4 and look at the Audirvana preferences, it indicates that the DAC is capable of 352.8 kHz operation:
However, it isn't - it's capable of 192 kHz max (PCM). (Audio MIDI Setup shows the same set of sample rates, I use the A+ screen because it also shows DSD.)
The response I received from Fostex Tech Support is: "Regarding the 352khz setting, this sample rate indication is reserved in the HP-A4 for when the device receives 5.6MHz DSD data sent using DoP (DSD over PCM) protocol. So the appearance of this sample rate is as designed."
So, would anyone happen to know enough of the details of how the DAC conveys sample rate capabilities to the computer to confirm what Fostex says - that a DAC that is capable of DSD128
has to also indicate that it's capable of 352.8 kHz PCM? (I think that's what Fostex is saying anyway.)
With A+, there's a couple of workarounds. One is to use a custom upsampling setting, another is to limit the max sample rate in the "bridge device" setting. However, with Amarra 3, which converts DSD to a high-rate PCM, DSD128 doesn't work properly. While DSD64 comes out at 176kHz, DSD128 comes out at 88.2k, and plays slow - I think one-quarter of the proper speed. So now I'm even more mystified and hoping that someone might be able to shed some light
