Can’t believe I haven’t noticed this until now. Playing middle C (that’s C4 on my keyboard) actually plays one octave deeper in OLGA. All oscillator pitch faders are on 0.
Why is this?
Hi Evildragon,
Check Options->Preferences->Media->MIDI->“MIDI octave name display offset” in Reaper and make sure it’s set to ‘0’. Then the key designated C4 on your keyboard should actually play C4/261.626Hz.
It is on 0 
When I play C4, OLGA plays C3. And I’m not guiding by Reaper’s octave markers, but my synth’s middle C. I play the basic piano sound on the synth, and any OLGA patch with oscillators coarse detune parameter on 0, and it’s octave below!
There are different opinions about what the “middle C” actually is, in the DAW and MIDI world C3 is often used as middle C with note#60 and so does Reaper and most synth VSTi, but not all plugins. The traditional notation refers to C4 as middle C (as it is the middle C on an 88key piano keyboard) and probably most piano VSTi follow the traditional definition (all I have do that), plus keyboards may follow the one or the other tradition and some send MIDI note# 60 on the key designated C3 (like my Keystation, I thought it sends C4=60, hence the confusion) and others on C4. AFAIK C4=60 is even defined by MIDI standard but apparently the bigger part of the industry decided not to follow for the past 25+ years. Lots of room for confusion but noone is actually “wrong”.
Isn’t that the most confusing thing ever 