Previously working amp, with an intermittent hum. I wiggle the left tube and it goes away.
I tightened some loose screws on the tube bases, trying to fix the issue. Now the hum is loud and constant, wiggling the tube does nothing. Amp is not usable.
I assume I have a bad solder in there somewhere? I've heard of it, but could you describe the chopstick trick you guys do to find bad connections?