This Silverface Deluxe Reverb is the version with 5U4 rectifier and push-pull Boost on Channel 2. In this video we will do a complete service and test. We'll clean all pots, grounds, jacks, and tube sockets. We'll replace a couple preamp tubes with RCA 7025, replace the 5U4 with a GZ34 for less sag and less current draw on the transformers 5V winding. Finally, we'll undo a modification to the output circuit wherein a previous tech had added cathode bias resistors and caps from grids 1 to cathodes on 6V6, then we'll re-bias the amp and test.