Any Eversolo Amp F10 owners out there ?

The dealer offered a replacement but FW is the problem.  So basically no fix.   A new one will have the more recent FW that did not fix the problem.  

Eversolo did nothing for me .   

Only version 1.2.50 FW and below work correctly.  New unit will not resolve the problem.   

@oddiofyl That is unfortunate for sure. I’m aware that the McIntosh DAC1 module present in the 8950 and many of the preamps have their own USB connectivity issues or their own, so perhaps the issue is more complicated than it seems, especially if the unit can connect to other DACs with no problems. This wouldn’t be the first time a firmware has botched something that was working previously, and sometimes, a firmware rewrites core functionality that is not easily reversible, which is why it is not always easy to roll back (I used to be a coder so I have some experience on this).

That said, there is no excuse for the lack of response you received on the Eversolo team on this. There should have at least been some communication to validate the issue and have either a clear path for issue logging, investigation, and resolution, or at least communication to show why they may not be able to offer a repair. Were you getting responses from them in the beginning? If not, I have to wonder if messages were going into a junk mail folder, but I’m guessing you checked there.

Knowing you, I’m 99% certain you looked into this but have to ask the obvious question - have you updated the firmware on the MA8950? I know that one of the later builds addresses some of the USB quirks the DAC1 units were known to possess.

It’s a DA2. Card. No further FW. It worked great. I believe it is as simple as them not having the right USB VID/PID. Vendor ID and Product ID tells the computer/ streamer what USB device is used. It used to display on the A6 before v 1.2.98. It would say "McIntosh 8950" Since 1.2.98 the USB icon is greyed out and you can't select. They obviously have a corrupt VID/PID in recent FW.