The Beaglebone Black comes out of the box with a completely functional Debian installation. I used apt-get to install ecasound and some ladspa plugins and I was off and running.
I found that with a delay ladspa plug-in I could run with a buffer size of 128, here’s the ecasound command line:
ecasound -b:128 -i alsahw,1,0 -o alsahw,1,0 -el:tap_stereo_echo,300,70,0,0,0,0,0
That’s a 300 ms delay with a lot of feedback. I measured the round trip latency at 15.4 milliseconds, which is pretty good, and CPU utilization was about 20%
When I got froggy and added a reverb plugin CPU utilization went to 70%.
So for my original intended purpose, which was to give me a digital delay capability without having to lug a lot of hardware, this would be adequate. Future posts will detail my scheme for parameter control and experimentation with other SBCs and Audio Interfaces.