Monday, January 2, 2012
Vox AC30CC2 Normal Channel Shutdown Hissy Fit
I've got a Vox AC30CC2 named Sophia Loren that is presently up for sale. This may be a cautionary tale about Resistentialism-which is the philosophical notion that things are out to get us. It also supports the notion that things have feelings and ways of punishing us.
I mean, you have to know that this amp has never been abused or scorned-it has never left my non smoking house either. It has, in a word, been spoiled rotten.
So a guy came to look at the amp and the normal channel quit working right in the middle of my sales pitch. Of course he more or less figured out at that point he was a Fender guy at heart, and so am I, which is why Sophia Loren was up for sale anyway. She was acting more like Roseann Barr at that point.
I got a little time today to dig into things and schlepped the chassis out and down to the laboratory. I started checking voltages and the preamp voltages seemed OK. Then a little grid disturbance testing led me to the first preamp tube's normal channel grid which produced no noise. Then, as if by magic the normal channel sprung to life. So, I tightened up the tube socket pins and retested and things were still on again, off again.
Looking through the holes in the vertical preamp chassis I could see that not only was pin seven-the one at issue-on the first preamp tube a lousy solder job, but pin seven on the second preamp tube was equally dodgy. I was able to reach through the holes and resolder the connections, and things are back to normal.
I know now that it's not right to threaten eviction when a needy and dependent lover is on the receiving end.