Them cryo-frozen valves look interesting... cheers Fran. 😀
Right, I'm not gonna do any more work on it until my new soldering iron arrives in the post, been overdue a new one for ages. Completely replaced the section of the circuit that is the fx loop and, happily, it works again! BUT, it's still really noisy. Having done some reading, the noise is actually a ground loop 'cause of the power supplies my pedals are plugged into, I'm gonna have to get a big proper power supply with isolated connections for each pedal if I want to use the fx loop.
Also, it turns out whatever I did didn't get rid of the apparently inherent noise of the amp, although using an ECC82 in the first gain stage instead of an ECC83 seems to work, but reduces my volume quite substantially...
On the plus, with that Mesa valve in the control valve socket, the amp reacts INCREDIBLY to my overdrive pedal. Will replace the rest of the preamp with Mesas when I've got the money, I think.
