this is something I’d like to do over the last year - and now I had some time to build my small DSO (a Bitscope-Micro with a 7" HDMI touch and a RPi2):
I created a simple test-adapter for MIDI and audio…
… and tested MIDI->audio latency of the standard Zynthian:
Here are the results. First I used the normal setup for the audio interface: 44.1kHz and 256 bytes of buffer. I tried several engines:
Linuxsampler with Synth/PadSynth:
MOD-UI with Dexed/FM-Piano
Pianoteq and MOD-UI have a latency of 16ms. Linuxsampler has a little bit more, about 24ms.
Now I restarted with a setup of 44.1kHz and a buffer size of 128:
Hmmm… different picture: Pianoteq about 15ms, Linuxsampler 12ms, MOD-UI 11ms…
I think I will try again the next days and see if I can find out if there were measurement problems or if this result is reproducable.
Just for comparision: The follwing measurements are made with my 30 years old Roland-D110. Remark: the time-base is changed from 5ms to 1ms, so the latency is about 4ms!!!