I bought a slightly used Classic 30 yesterday. Everything was working fine at the seller's house, when I got home, one of the preamp tubes had died (probably shaken to death during the 1 and a half hour drive), so today I went to guitar center and bought a new preamp tube to replace it. The weird thing is, the amp will play for about 5 minutes, start cracking up, and then stop making any sound. If I tilt the amp forward a little, it starts playing again, but if I set it back down, it stops. Any reason why and how can I possibly fix this?
the tube you bought is ****ed up?
It seems like it's a dodgy amp, contact the seller?
Take it to a tech man