USB Sound Card issues


I have got Virtualhere running on RaspberyPi and have been successful it getting a number of different RS232 comms port devices working. However, when I try a USB sound card I have different levels of failure.
I have tried out two different devices (a) Sound Blaster Live 24 and (b) C-Media.
The client is running on a Windows 8 VM which is running on VM Fusion.
With the Sound Blaster the device appears to connect and shows up in the audio properties, I can see both the input and output along with the other sound devices. No sound appears to get through, even after checking to ensure nothing is muted. With the C-Media the client starts to initialise and the device starts to appear in the sound properties but Windows 8 then stops responding and after a period I get the equivalent of the windows blue screen of death and a short message saying that there was a Bad Pool Header. The sound cards do work with the Raspberry PI as I have tested them with an audio application on the PI.

I also have two radios with USB inputs, and when theses are plugged in to the RaspberryPI they do not even register with Virtualhere. Am I expecting to much? Are there limits as to what devices can work with Virtualhere?



Hi ian, at the moment isochronous (sound) on raspberry pi via USB is flakey. I think you need to wait for updates to the kernel. For example in the old kernel from feb my test setup with a logitech speakers was working fine, now with the latest kernel it is broken. Since Virtualhere relies on the kernel to perform usb functions if the usb is broken in the kernel then virtualhere cannot work. The best thing to do is wait until this bug is fixed in the raspbian kernel.

RS232 etc all work because they use Control/Bulk/Interrupt transfers which are pretty reliable in Raspberry pi now.

What is the model of the radio's and i will take a look at their specs in the internet?


Thanks for the update. Since my original post, I thought I would try setting up a Ububtu VM and try that.
So I have a Ubuntu VM running the server and a Windows 8 VM running the client.
Serial comms work OK. The sound cards now appear to connect and show up in the sound properties and there is no instability but no sound.
the Ubuntu VM is version 12.04.3. So is it likely that the Ubuntu desktop may have a similar issue?

I tried running the MAC client and the little window shows the device has connected but I cannot see it in OSX.
When I check system information under USB I can see a Virtual Root Hub but no devices connected.

The Radio are an ICOM 9100, ICOM PCR2500 and a FLEX1500.

I will be trying out connecting USB disk drives later.




Does your pi have an external ip i can connect to at my office. Send me an email at mail [at] and i will login and see whats happening with the radios. I checked their configuration and it should work fine with virtualhere because they are just a com port.

Actually i think there is a bug in the soundcards stuff... i will check on this and let you know if/when a new build is available


I thought it best to re-trace my footsteps regarding the radios. I can confirm that they do connect to the PI and I can then connect via the client and control the radios. In addition to the serial functionality there is, you probable have guest it "sound". The sound drives do load on the client but no sound. So I now know I can control the radios remotely over IP, which is a big step forward.
You comment about a bug in the soundcards stuff is noted.

Thanks for responding so quickly.


I have bought a lecroy mercury t2 hardware analyzer for hardware level tracing and im currently using it to trace the audio issues with my usb speakers. ...will let you know if i have any updates


I have tried the Raspberry Pi 3 and Beagle Bone Black rev C to get the Icom PCR2500 connect through VH, but so far without any luck. The Pi 3 is crashing as soon the PCR2500 USB connector is plugged in and with the BBB in use the serial connection drops as soon the audio port is opened... The client is Windows 10. Both boards are running Debian Jessie fully updated with full license of VH. Michael, do you have any suggestions?


Dear Michael, thank you once again for the active support we have received. The application with the Icom PCR2500 receiver is running smooth and stable now on the BeagleBone Black. Updating all software to the latest version was the solution. As mentioned is the audio connection not as stable due to possible latency in the network link, we have to see how this behaves in the real world and if needed we might implement an audio broadcast stream from the analog output of the radio. Herewith our setup and driver versions that worked:

  • Kernel: Linux beaglebone-vh 4.4.9-ti-r25 armv7l GNU/Linux
  • Virtual Here server linux: vhusbdarmbb v3.1.0
  • Client PC running Windows 10 64bit
  • Virtual Here client Windows 64bit: v3.8.2
  • Icom PCR2500 Firmware data (Ver.2.10) 2013/10/01
  • Icom PCR2500 Control software (Ver.2.201) 2013/10/01
  • SiLabs CP210x USB to UART Driver version 2016/03/28 (this driver wasn't distributed by Microsoft and had to be installed manually)

Maybe good to share for other users, the PCR2500 didn't work when we used a Raspberry Pi 3 (Raspbian) or OS X 10.11 as VH server.


Thanks for that, virtualhere has quite a few ham radio users so thats helpful!