[Solved-ish] Slewing velocity in Just Friends and Teletype for a harmonic oscillator patch

I’m trying to build a flexible harmonic oscillator patch using Just Friends, Teletype and TXi (mainly to avoid GAS associated with watching too many Verbos Harmonic Oscillator videos!). I’m planning to use JF.VTR to set the volume of the individual partials on Just Friends (and have these set either programmatically or via inputs from TXi), but I was hoping to be able to fade them in and out rapidly to avoid clicks (basically a wee ramp to the new level each time). I know we can add slew to CV outputs but I guess this isn’t possible with i2c instructions? Anyone have any smart ideas of how to do this? Even if it’s sending a bunch of JF.VTR commands one after another, I’m kind of blanking on what’s the best way of coding this on Teletype in a space efficient way. Thanks!

It’s not possible to slew i2c instructions/messages - they are discrete events. You might be able to send them fast enough that it isn’t noticeable or minimize the number of messages sent, but you will be constrained by the limitations of the bus. It might be fine though.

PLUME may also be useful for this; at least it’ll be easier on your i2c bus.

1 Like

oh - good call! I forgot about PLUME (those pesky run modes!). I wish there was a way to control spectral tilt on JF, but I can sacrifice some mixer channels… Thanks!

EDIT: a little more investigation, should anyone come upon this thread. If you use PLUME in combination with JF.VTR it doesn’t do what I would have expected. As soon as you set the velocity as anything other than zero, all the partials sound constantly at that velocity, and JF ignores the trigger inputs (sadly). So, it’s not possible to set up some kind of curve over the harmonics and then trigger ones individually (which is what I was really hoping to do in my quest to figure out how Caterina Barbieri makes such polyphonic magic out of a single oscillator!). On the other hand, I’ve found that using JF.VTR over i2c is surprisingly smooth and click free, so I have a hunch that there’s some kind of ramp already in the JF code.