I am not a DSD user. But when my new Topping DX Pro+ desktop dac and headphone amplifier arrived a few days ago, I wanted to give it a try. With USB-in the DX3 supports DSD64-DSD512 (Native) and DSD64-DSD256 (DoP). As I am a Mac user, I had to learn that macOS obviously does not stream DSD naitive, but if the DAC supports a PCM rate capable of carrying the DSD, it will work. So for DSD 256 to work with DoP, the DAC must be PCM 768 capable. That is the case with the DX3 Pro+.
But what a disappointment! When playing my first DSD file everything looked fine, Audirvana displayed the correct sample rate, but the dac showed still PCM and worst of all, nothing was to hear! As with the Colibri app playing of DSD worked fine, I tried several settings in Audirvana, but nothing helped. Nothing before I found out, that volume in Audirvana Studio has to be set to maximum! (If you try, be careful with the volume setting of your dac!) When maximum (-0 db) was reached, the DX3 pro+ suddenly showed the exact sampling rate and played fine. At that moment software volume control was disabled, but it is the same with volume control enabled. And it is the same behavior with Audirvana 3.5.
So: To play a DSD file with Audirvana via DX3 Pro+ in DoP-mode, volume in the app obviously has be set to maximum, otherwise the file is not recognized as DSD by the Topping and there is no sound output.
My anyone kindly explain this to me? Is it specific to DSD, Audirvana or the Topping DX3 Pro+?