Then there was this idea. A friend gave me an old carrilon (church bell) amp that he got cold feet on when a capacitor blew up on him. I thought it might make a pretty good guitar amp. I gutted it and rebuilt it as a simple, single-channel guitar amp. It uses two EL34 tubes, and has a fairly unique sound…
I wanted to build an amp using EL34 tubes…
This amp seemed like a good candidate: fairly chunky iron, a solid-state rectifier, 2x 6CA7 (the American designation for what the British call an EL34). I had to gut much of the interior, removing three other channels, plus a smaller 7-pin preamp tube that I wasn’t going to use. I had to convert the existing 12.6v SERIES filament wiring scheme to 6.3v PARALLEL filament wiring. I borrowed the B+ wiring circuit from an old HiWatt schematic I had. One feature of the amp that I KEPT was a dual concentric pot wired up for bias adjustment of EACH power tube, plus the RCA jack test points to monitor the bias — a pretty cool feature for the 1950’s? 1960’s?…
How’s it sound? It sounds really good! It has a lot of oomph, but with a very distinguishable midrange bump characteristic of these output tubes…
