USB sound card no audio

Hello!

First of all, congratulations on excellent service and this really good concept.

Right, what I`m trying to do, is connect my ham radio to my Raspberry Pi 2 and access remotely from my shed. (The radio is in a cupboard in a house)

A few details if you will indulge me...

Rig: Icom IC-7100 - Has own built-in USB sound card (as a Silicon Labs CP virtual COM port and virtual USB audio device...
Raspberry Pi: Latest Raspbian Jessie / VNC
Connection: Cat 7 u/ftp cabling

Problem: No audio through Virtualhere server. Everything else working fine.

I am aware that the Pi has had issues in the past with isochronous transfers, and I have gathered from searching the Googleweb that this was fixed in the 3.12 kernel but I am getting no audio at all. I can control the radio etc as expected, just the audio is silent.

I know it isn`t the app configuration on the server side, as 1) It controls the radio flawlessly (and the audio comes through the same virtual COM port) and if I plug the radio directly in to the x86 client I am using, it is working straight away. (I don`t even need to modify COM port numbers).

Latency isn`t a problem, there is ZERO audio at all. Tried on my Pi zero (with Wifi obviously), Pi B, Pi 2 with same results.

Wondered if anyone had any thoughts?

Many thanks

Matt