Olivier has replied here:
Hi,
First of all, on Windows, you must choose the good host (asio, wasapi (default as of 0.8.7), mme, etc.) and, if needed the good device ( Server.setOutputDevice(device_index) ). There is a script in the pyo documentation to test the audio setup on your system:
http://ajaxsoundstudio.com/pyodoc/winaudioinspect.html
Then, if you’re using wasapi, be sure there is both an output AND an input configured on your system (it’s not always the case on Windows). Otherwise, you boot the Server in output only by setting the duplex argument to 0. Sampling rate of pyo must also match the sampling rate of the system (System’s sr is often 48000 while pyo’s default is 44100).
Now, in your code, you should always call Server.stop() when you’re done so that pyo can properly release the audio driver. Maybe that’s the problem described in that post. If a process didn’t release the driver, subsequent attempts will probably fail.