I believe this normally uses a 5Y3GT rectifier, two 6V6 output tubes, two 6SN7 tubes, and one 6SL7 tube (far left). The three potentiometers in here are 1956 Stackpole 1 meg potentiometers, and are probably audio taper. These are worth a lot by themselves.This has one wire underneath that is not connected, so I did not test this. Also, the AC cord has a bit of damage and should probably be replaced. This should be fully rebuilt in order to work properly. It will be an amazing amp once it's done. Please see my pictures for details. If you have any questions, please ask. I have more amplifiers and other vintage electronics listed--feel free to take a look! This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps".music" and is located in this country: US. This item can be shipped worldwide.