When synchronizing Polyend Synth by sending MIDI Clock via MIDI jack In, the Delay effect becomes kind of unusable. It produces all kinds of artifacts. To be clear, I am synchronizing Polyend Synth via another Groovebox.
Since Syncing via MIDI is never 100% CPU accurate the Delay Effect seems to react unfavorably to the minuscule speed changes. I tried syncing Synth with the following devices: Elektron Syntakt, Digitakt 2 and Polyend Tracker+ all with the same result. If I make the Delay time unsynced, it behaves normally.
I have not tried this with USB Midi.
Hey @eric.n.ahrens, this is a known issue and a fix is being worked on: