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Jumpy Filter sweeps on SP

Posted: Wed Jan 31, 2018 12:03 am
by gdgross
Hey guys, Im a new owner of a (used) Slim Phatty - love the sounds in that thing, and presets are a good starting place for synth noob like me.

The other day I was using the SP to record audio out, running from MIDI over USB from protools. Manually running the filter with my hand as the song records. The filter response seemed pretty jumpy, or quantized maybe.

When I use the moog external footcontroller pedal, I don'e experience any of this jumpy behaviour. Any ideas? I'd rather use my fingers than my feet for this.

Thanks!
Geoff

Re: Jumpy Filter sweeps on SP

Posted: Wed Jan 31, 2018 8:55 am
by stiiiiiiive
Hey Geoff, welcome to the forum.

I guess it's a matter if MIDI loop. Try setting up ProTools so that it does not send any MIDI data back to the Slim. Or set up the Slim so that is does not receive MIDI through USB.

Re: Jumpy Filter sweeps on SP

Posted: Wed Jan 31, 2018 2:49 pm
by hieronymous
gdgross wrote:The other day I was using the SP to record audio out, running from MIDI over USB from protools. Manually running the filter with my hand as the song records. The filter response seemed pretty jumpy, or quantized maybe.

When I use the moog external footcontroller pedal, I don'e experience any of this jumpy behaviour. Any ideas? I'd rather use my fingers than my feet for this.
Can you check if the jumpy filter comes out of the headphone out? Maybe exercise the pot? (Turn it back and forth throughout the whole range a whole bunch of times) I noticed that kind of thing with my LP Tribute (which is an older instrument) and exercising the pot seems to have helped.

Re: Jumpy Filter sweeps on SP

Posted: Tue Mar 20, 2018 8:04 pm
by gdgross
Hi guys sorry for the slow reply here. new dad, blah blah, synths are secondaty to my gutiar playing, yada yada. Played around with the SP and ended up recording those tracks using the filter sweep through the footwitch so i dodged the issue. have a little time in the next few days so i'll take a closer look.

Anyway, I'll try using normal MIDI instead of USB, but I have to have Protools send the midi data into the SP, that's the whole point haha.

I did try exercising the pot a bunch and it doesn't seem related to that. I also don't hear it when I'm just playing thoguh the SP using my midi controller, which sort of emphasizes the previous point.

Thanks :-)

Re: Jumpy Filter sweeps on SP

Posted: Sat Mar 31, 2018 3:01 pm
by gdgross
K, set up the SP so that it does not send midi out data, and I'm still getting the jumps in the filter. They are subtle, but they are definitely there. Seems if i move the filter now more slowly the jumps are less frequent, but not altogether gone.

I've tried receiving MIDI in both from a USB cable and my Maudio USB to midi converter, same result. I also believe I misspoke earlier - It DOES happen when I'm driving the SP from my keyboard via a single 5 pin MIDI cable, so I'm pretty sure it's the SP.

Could I be hearing the steps of the filter, or is it fully analog? (is it digitally controlled? or is that light up ring just an indicator?)

could it also be that this is just the way the SP works? It doesn't bother except when I'm sweeping the filter slowly across a small range. wide sweeps its not too noticeable.

Re: Jumpy Filter sweeps on SP

Posted: Sun Apr 01, 2018 10:23 am
by stiiiiiiive
The Slim Phatty design is such that potentiometers directly drive the analogue circuit. I'd bet on any MIDI related issue rather than on the SP itself. Not very useful here, sorry...

Re: Jumpy Filter sweeps on SP

Posted: Thu Apr 12, 2018 11:24 pm
by gdgross
Thanks I'm starting to think that too.