Volume jumps around erratically at some levels. Is this a potentiometer issue? Do I just need to get some contact cleaner somewhere in there? Unit is four years old.
To see if it is the master volume knob: turn the master volume knob; when the output menu comes up, disable the output you are using. Now the master volume knob should not affect output at all.
Before spraying contact cleaner, I’d isolate whether it is the Quad Cortex’s master control or the output path. Try the master knob with each physical output and USB output disabled in turn, then see whether the level jumps at the same knob position. Also test a different cable and monitor/headphone input. If the problem follows the master knob across outputs, save a backup and contact Neural support rather than opening it—contact cleaner can get into the wrong parts and may not help a worn encoder or potentiometer.
Probably will need Neural to repair the QC. This is a common issue with these. At least from all the posts on here and Reddit