Gerhard Zintel <gerhard.zintel@xxxxxx> writes: > Does anyone of you know if the original swell pedal of the B3 is > changing the volume in a linear or logarithmic way? Here's a quick recording from the output of my C3 (same internals as the B3 in a different case), with the drawbars at 88 8888 888, holding down Cs across four octaves and moving the swell pedal as smoothly as I can between the endstops: http://offog.org/stuff/c3-swell.flac This looks more or less linear to me by eye. Note it doesn't go all the way down to silence. However, in terms of the preamp circuit it's not quite that simple -- the swell pedal isn't a variable resistor, it's an unusual variable capacitor with two fixed plates and a moving one, in between two valve buffer stages. One fixed plate is fed directly from the previous buffer, and the other is fed through a filter circuit -- so effectively the pedal is crossfading between the full signal and a filtered and attenuated version of it (simulating a real organ's swell box with the shutters closed, I guess), which means that there's some variation in the frequency response as well. This also disregards any nonlinearity in what you're playing the organ into -- if you're doing the traditional overdriven Leslie thing, then there'll come a point where it gets crunchier rather than louder... Cheers, -- Adam Sampson <ats@xxxxxxxxx> <http://offog.org/> _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx https://lists.linuxaudio.org/listinfo/linux-audio-user
