Fascinating banding in the original unit.
Hear the clips: note the difference in tone and the occasional clicks.
My Presonus Revelator io24 started sounding ‘muggy’ on me recently. With Don Baarns’ kind help we isolated the problem – swap out mics, cables, use a field recorder with original mic and cable, blah, blah… until we had it down to the interface itself. Called Sweetwater and they very helpfully overnighted a replacement. Yay for the team! Here is the audio – raw except for a high pass filter I left on with the new one – you’ll see the clean low end on the last part of the display. Interesting – and, thankfully, rare problem.