[MrFixr55]

Hi Joe,

Thanks for posting the schematic. Interesting set, looks like they were trying to build a console set on a budget. That an 8" or 6" speaker? The dial came out sweet.

The 6AC5 tube is an interesting beast. It's a high MU triode usually used in Class B Push Pull output stages, as it puts out quite a bit of power albeit with the higher distortion that class B is known for. In single end and in some push pull stages, it is paired with a triode connected as a "cathode follower, directly connected to the 6AC5 grid. The tube operates with positive bias in this mode, with high wattage and very high distortion (10-16% for single end per the RCA Receiving Tube manual). Class B was popular with RCA in the early 1930s and probably in car radios, but the only set I ever saw 6AC5s in was a 1941-42 Crosley 02-CA console. 10 tubes, Audio stage had 6 tubes:
1 6SQ7 Detector / 1st Audio
1 6J5 as a cathodyne phase converter
2 6j5s as cathode follower drivers for the output tubes
2 6AC5s as Class B output.

Distortion was higher at low output but the person I restored the chassis for likes to play Jazz guitar. I had put an external "Radio / Aux" switch and jack in the set. He plugs his guitar in and it actually makes a rather sweet guitar amp for jazz guitar through the 12" speaker. No overdrive, as one would expect, given not enough preamp stages, nice sound, in the way electric guitar was first played before the high distortion overdriven "metallic" sound.