@tomic601 I have an extra Model 4 I bought used, initially. It has a faint hum but sounds great otherwise. Rather than mess around with repairing I just bought a new one after speaking with the owner who said 100% the hum is a fault somewhere, probably just a loose ground. I was planning on sending it to Japan to get fixed and then resell it, but shipping is $175 so I’m reluctant to do that.

