Recently I obtained an old chassis and after restoration it gave a pleasant, lifely 4-5W. Here's the schematic:
The cathode connection struck me as odd because both posive and negative feedback is applied. I don't get it.
Furthermore bass is not very deep, I'd guess below 50Hz is non existant. Raising the value of C1 (and C2 while lowering R7) didn't bring happiness. I wonder if someone can model the stage preceding T2 for bandwidth. The OPT is heavy but it's quite ancient, I have no specs for it. Another suspect there 😉
An externally hosted image should be here but it was not working when we last tested it.
The cathode connection struck me as odd because both posive and negative feedback is applied. I don't get it.
Furthermore bass is not very deep, I'd guess below 50Hz is non existant. Raising the value of C1 (and C2 while lowering R7) didn't bring happiness. I wonder if someone can model the stage preceding T2 for bandwidth. The OPT is heavy but it's quite ancient, I have no specs for it. Another suspect there 😉