I am building a power amplifier with 6CZ5 and 6GH8 tubes. I am using a Knight KA-55, Stereo 40 amplifier that probably never worked because it was wired wrong. I purchased two St-70 boards from ebay. They came from tubes.rs and look real good. My output transformers are 6.6k and were checked by injecting 6.36 volts into the 8 ohm taps. Nothing smoked and I observed 185v and 184v between the plate windings and 2.18v from each center tap. My problem is simple I am sure but not for me. My voltage on the left channel is way off and after the 820k resistor I get only 18v. On the right channel I get 48v. should be around 40v and I will take care of that after I figure the left channel problem out. I went ahead and built the second board and switched them out to no avail, it did the same thing. I am going back over the boards tonight. There is a short somewhere.
I am not allowed to post a link for the schematics used to build the PC3 board and the amplifier. Maybe an admin can give me permission to post the link. It is an RCA high fidelity design for 7199 and 6973 tubes. If any of you have any thoughts, ideas or comments please share them.
Thanks, Tom
I am not allowed to post a link for the schematics used to build the PC3 board and the amplifier. Maybe an admin can give me permission to post the link. It is an RCA high fidelity design for 7199 and 6973 tubes. If any of you have any thoughts, ideas or comments please share them.
Thanks, Tom