This project came about because I got a reel to reel that used a 12AB5 power tube (which I'd never tried before) and the PT had a 12volt filament winding instead of the normal 6 volt. First, I hacked and tacked a circuit together to see what it would kinda sound like. The PT hummed and vibrated like mad, but did put out the juice I needed. So before I did anything else, I wire brushed the outside of it, took off the end bells, and gave it a good heavy coat of paint. Then, trusting in God and luck, I went ahead and built the amp.



I put the OT and RT inside the chassis (output and reverb transformers). I wondered about inducing hum into the circuit. There's nothing. I assume the full metal enclosure on the transformers helps with that quite a lot. Nearly everything inside, except for those trannies, was stuff I already had from this & that and here & there.







It never made it into a cabinet yet. One day I'll get a round tuit.





The sand and paint job worked on the PT, the whole amp is dead quiet till it hits about 3/4 on the volume knob. It breaks up early. Here's the as-built schematic.

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