I checked my cabling and couldn’t find a fault there.
The p5 input is feed from an balanced source, here i use a unbalanced cable ( where pin 3 is connected to pin 1 on the xlr ) which connects to the balanced out of the sending device.
The p5 out is connected to the balanced input of the receiving device via standard balanced cable.
It seems that levels match better when In and Out Gains are set to very different values like very low input and high output or vice versa.
Around the zero position settings – which I use most – levels tend to match less.
Would it be worth a try to clean the pots with something like DeoxIT?
Thanks for offering the opportunity to sent the p5 to you, but I would rather not prefer to because I’m located onshore ( vienna ) and I am afraid of possible troubles due poor treatment during transport over to the royal island.