Amp 2: AX84 November
I built my second amp shortly after my first. This amp was the November from the AX84 project. It sounded really good, and gave me a variety of tones as I could now switch between the two amps.
This amp had a few problems. Due to a mistake early on, I built the circuit card backwards. I build the circuit card for right to left controls (like a Marshall) but I installed the controls left to right. As a result, some wires were longer than they should have been, and the bright channel had a huge noise problem. I had to keep the volume on the bright channel dialed down to zero in order to play at all.
Disaster struck one day when I turned it on, heard a faint fizzle from inside the amp, and the light turned off. The fuse had blown. I later diagnosed the problem as a shorted rectifier, but I was unhappy with the amp’s noise level so I scavenged the parts for my third amplifier.
Lessons Learned
- Diodes can short.
- Circuit layout is important. Keep noise sources, such as rectifiers, away from inputs.