pitchbend conversion

michelez's icon

I am experiencing less than accurate pitch conversions when I use midi fractional values to create pitchbend CC values. For example if my midi 72.34 and I use [scale 0. 1. 0 127] to scale transform the 0.34 into a pitchbend I get wrong results.

Can somebody help me get the right conversion?

Source Audio's icon

is pitch bend not depending on pb range set in synth?
it could be +- 12 semi tones, but could also be anything else.
pb 0 - 127 covers the whole +- range.
your offset from C#5 is 34 cents or 0.34 semitones.
divide 128 with pb range to get value for 1 semitone, and multiply it by 0.34

128 / pb range * 0.34 + 64

michelez's icon

That's what I was looking for, thanks!!! I am sending it to Reaper and Surge (VST synth). I am not sure about the transformation I have to make to get it right there but I can try, or just look at the Surge manual...

michelez's icon

I was just introduced to the @hires attribute that allows for the pb to be expressed as a -1<>1, with more float precision, do I still need to look into the Surge's pb specs?

Source Audio's icon

you can simply test it - send pbend 1. and listen to transposition...
1. / 12. (pb range) *.034

Max Patch
Copy patch and select New From Clipboard in Max.


P.S. in that patch it is calculated for 1/2 pb range

michelez's icon

great, thanks!