Came across this little amp from a friend of mine that I had done some website work for. Basically it was a “somewhat” functional, meaning the chassis was there along with most of the parts. Since I am not much for a clean or bluesy sounding amp I decided to gut the preamp and phase inverter to do some hotrodding, thus giving the amp a new life.

I started with a basic Marshall 1987 preamp and phase inverter coupled to the original power amp section. The first set of mods that were done were putting in a switch that would cascade the bright channel into the normal channel for a major gain boost, added a switch to change the cathode resistors on the normal channel from stock (820 ohm / .68uf cap) to just a 10k (ala JCM800). This gave the amp plenty of gain on tap. Not bad for a 40+ year amp. It still lacked the modern grind that you hear some people playing. So I had decided to mod the preamp a little more.

During the testing phase of the updated preamp section, one of the filter caps decided it was tired and quit working. So right now it is sitting incomplete until I can get some more can caps.