unwanted granular sample distortion when USB connected?

so i’m running the OP-1 with an ableton patch, just sending it midi notes for a drum pattern over the usb and occasionally playing additional patterns over that on the finger sequencer. trouble is, I inevitably start getting this distortion that sounds like a granular sample distortion or bitcrush of some kind. I eliminated everything else in the signal path, and it occurs evenly no matter where the volume knob is, both with the headphone jack and internal speaker. once it starts it even keeps occurring if I unplug the usb and just play it on it’s own. restarting seems to reset the problem, but it always returns.

anyone have any insight on this? does the device not play well when it is receiving midi and also being played via the keyboard maybe? is there a workaround?

new to the forum, any help would be greatly appreciated.

The fact that it continues even after unplugging is unusual, but one thing to try anyway is to shut off USB powering. Shift+COM+T4 I think, then one of the knobs to disable the connection. It can be a cause of noise, ground loops and such, but not normally what you’re describing. Might as well try it out though.

Could there be any stray messages coming through that might cause unexpected action? CC’s, program changes, stuff like that. (not that it should make an issue)

You say “inevitably start getting distortion,” is it something that doesn’t happen instantly when you start playing it? Or only after a little while of sending MIDI notes and such?
Thanks for the heads up on the charging, I'll definitely do that but I can't imagine it's the cause.

No stray cc's that I can find, but would velocity changes be an issue?

And I haven't found a tried-and-true way of getting the problem to start yet, but it tends to start if I switch between the drum preset keys. So yes, as far as I can tell right now, it's only after a short while of sending midi notes.

That’s really weird. Could you make a video or an audio recording of it?

Nearly all of the noise issues I have encountered with the OP-1 have been down to two things.

1: Power management when connected to USB. It chirps, grunts and chitters away. Disconnect power from USB and the noise goes. This is present on headphone and speaker.

2: Accidentally leaving the audio input active on microphone.

Is it also possible that it’s trying to play too many notes?

ever find a solution? im having this same problem. i seem to have isolated it to when sequencers are being used and usb is connected to computer (with usb charging turned off). Im able to get a pretty silent noise floor from the audio out, but when i turn on some of the sequencers, that same granular feedback your describing starts coming through non stop. if i unplug the usb it stops immediately, but starts again when plugged back in. powering the op1 off and back on and then reconnecting usb seems to reset the noise but then turn a sequencer on and its back…