Something is modulating my filter on T3

I experienced an unexpected sound modulation during a jam session yesterday, seemingly coming from track 3 on my Analog Four (and only track 3), despite having set the first filter of T3 to the lowest frequency. It resembled a (synchronized) LFO modulating the cutoff. I checked and then deactivated both LFOs, removed envelope modulation, and verified the performance knobs were set to 0, but the sound persisted.

Setup Context

  • Sequencing the A4 with the Oxi, which also sends out the clock.
  • Audio from A4 routes to Octatrack and MIDI goes to Analog Rytm before reaching the Octa.

Debugging Findings

  • Starting the sequence from the Oxi triggers the modulation on track 3’s filter.
  • Rebooting the A4 and playing a sequence internally eliminates the modulation.
  • Restarting from the Oxi then stopping, and playing something internally on the A4 without rebooting brings back the modulation.

After rebooting all devices today, the modulation issue disappeared without changing any kits or patterns on any of the machines, including the Oxi, leaving me puzzled.

Seeking Advice
Although the issue has resolved itself for now, I’d appreciate any insights on what might have caused it, especially to prevent potential problems during a live performance. Does anyone have suggestions on where to start looking should this occur again?

Thank you almighty oracle.

does the oxi maybe have a modwheel event sending in the sequence, and the A4 is set up to map modwheel to LFO depth?

1 Like

Well, I thought about that too but that wouldn’t explain why the modulation would still happen when I’m only playing the A4. So I pressed play and then stop on the Oxi. Then afterwards only playing the A4 and I would still hear the modulation.

If I would reboot the A4 then the modulation is gone when playing only on the A4 without touching the Oxi.

modwheel values would stay until a new value comes in to clear it. look in the part settings to see if modwheel is set to anything, and disable it, and see if it still happens. same with aftertouch

3 Likes

Wow. Well, if it happens again I’ll definitely check this. Never knew these signals persisted. I already ruled out anything on the Oxi because it wasn’t sequencing the A4 anymore.

Appreciate your effort th0mas. Thanks!

You might also want to check if this is a (already known) bug.

1 Like

Could also be a Performance macro maybe.
Does it happen whatever the Kit, especially a blank one?

Good find. This looks relevant. Guess it’s a minor issue though. Didn’t encounter it anymore but also saved many iterations over that sound and kit.

No performance macro set. I’m certain everything on A4 had no depth set to any modulation knob.

1 Like