yesterday TUNATHOR (with an ES-9) let me play an old “MFOS mini synth” which I used to play only for my awful terror drones…its oscillator is very unstable but its range goes far from what we can hear (and also has VERY nice oscillators and a VERY nice filter), so it worked perfectly…
today I struggled to used it with my behringer K-2 because of the “range” problem. I had to use only vco 2 that reaches 2 feet, and set the “master tune” a little bit lower than normal because TUNATHOR was not able to “catch” the first frequency (around 32Hz).
then I had to offset of 1V the CV (Calibration Volt Out —> + 1V —> ES-9) and started the procedure.
to find out the range I used the “fast octave mode”, and once I figured out that it can tune it from the bottom to the top I restarted it on the “semitone” mode
I thinkg TUNATHOR looks for the range between C1 and C7, so, if the oscillator can’t reach 30-4200Hz it stops working
with this I also say a big THANK YOU to @synthi