[Voyage-linux] AUDIO_GD DI V3 - Digital synchronization issue

[michele pasciuti]

I have the following audio setup:
 
Alix 3D2 with Voyage MPD 0.9.rc2
USB converter Audio-gd DI V3
DAC (spdif to anolog converter): Wyred 4S DAC 1
 
The USB converter is a quite new product and employs VIA Envy VT1731 which is claimed as 2-channel 32-bit/384KHz capability and USB 2.0 high speed device compliant.
It can be powered from USB port of from an external supply (there is a switch with 3 position: OFF – USB – EXTERNAL).
This converter is factory shipped in async operation mode but the manufacturer includes also a spare chip (I think this is the chip which manages the USB input) which, when installed, switches the mode to adaptive one. 
 
The USB converter is detected by MPD but If I run alsamixer I have no controls available (message is “this device has no controls”).
 
In addition to this I am experiencing some strange issue during the async operation (no issues instead in the adaptive one).
After powering-on the USB, as soon as a song is played the stream stays locked at 192khz (I see the sample rate on the display of the DAC) even if I am playing a 44 or 96khz tune. The sound that I hear has lots of distortion. If I stop and then re-play the same song the sound becomes ok with the right frequency shown on the display. 
The same happen if I switch between two songs with different sample rates: it seems that the signal keeps locked at the previous rate and I have always to stop and re-play in order to operate at he right one.
I have tried also with external supply but no change.
 
Any suggestions ?
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