Settings for abusing filter standalone, no MIDI notes

This is for Andre’s stereo shruthi, firmware .97: I have to kick open the filter with a MIDI note even when the ‘not’ to ‘cut’ amount is set to -63 in the modulation matrix…is there a way to make it so all control (all the way open / closed) is via the knobs?
I am sending an audio signal into the shruthi and want to use it strictly as a filter and noise source.

maybe you can use the cv ins and make a momentary button or knob and dedicate an assignment to that cut amount in the mod matrix?

edit: OOOOH i got that request wrong :slight_smile:

Are you talking about the fact the signal is being gated without a keypress? If so, you just need to open the VCA in the matrix… In fact isn’t that what you get when you disable to default env->vca routing?

I’m not sure exactly what is happening but without sending a higher range MIDI note, the filter doesn’t open all the way. e.g. when I power up, then go to the patch and turn cutoff to 127 it sounds like it is only halfway open. When I plug in my controller and hit a MIDI note then the filter opens all the way. After that inital note I can unplug the controller, change patch and come back to the first patch and the knob can still open the filter all the way. After powering down it reverts to needing that initial MIDI note.

I am not familiar with the stereo filter, but aren’t there trim pots on the board for adjusting the main position and key-tracking of the cutoff to calibrate it to 1V/Oct?

If there are, make sure you use TubeOhm’s filter calibration tool, and get those set properly.

The low cutoff aside, the Shruthi has a default routing that lets the filter track the keys, and that is why you can adjust the filter with a high midi value.

Ah, I think I know what’s happening… When the Shruthi first boots, I think it acts as if the last note played was MIDI note 0 and the filter tracking is following this and therefore pulling the cutoff really low (the cutoff value in the shruthi is in semitones when the filter is properly calibrated (AFAIK), so 127 will always be however many semitones above whatever the centre point is calibrated as (as in the cutoff value that resonates at the fundamental of whatever note you’re playing).

I fixed that in later firmware versions.

Hi yes but the problem in later firmware versions is that you don’t have the free proged pots .
This is the reason why i use the older 0.97 version special for ‘tffshtt’.Normally i deliver the 1.02 Version .

Well, you can fix the 0.97 version with the change from the 1.02 version…

ok, thanks for the idea…