1976 Twin Reverb customer's amp specs: - Non-pull boost - Has Master Volume - Not Ultra Linear - Has Heater Hum Balance - Bias Balance circuit - No Power Tube Hum Balance - Chassis SN B60387 Thought I would start a thread for those interested in following along. A local young musician bought this amp 5 or so years ago. It had been heavily modified by someone before him. Some type of pull boost fuzz. Vibrato circuit was all ripped out. An FX loop added. A line out added. I was asked to bring it back to stock. I started with the original layout and schematic and traced everything in the amp. I used 2 colour hi-lighters. Everything stock was coloured in yellow, everything that was missing or modded was coloured pink. I put together a parts list and ordered everything I think I need from Doug Hoffman. Then I got to solder sucking and yanking all the mods out. Everything on the bench here in front of the chassis was what I pulled out. I have no idea what the heck the mini added power transformer was for. Customer said amp seemed to play ok but was a little lifeless. I discovered original B+ caps, bias and cathode caps still in the amp. Today my order from Doug arrived. This may be a little out of my comfort zone. We'll see. I may need some help from some of you kind folks. Here we go, time to get to work. I'll start by measuring all resistor values and label them for quick access.