Hello everyone,
I just finished wiring up the engineer's amp board with the recommended Edcor outputs. While trying to make the bias and balance adjustments I discovered an issue. I had checked the b+ before trying to adjust and it was okay. I could not get the left channel current test points to rise above around .355mv. I swapped the tubes around but the problem stayed in the same place. I'm getting 328v b+. On the left channel I get 298v on PLT1 but PLT2 reads negative 300mv. The plate of both 6cb6 tubes is around 155v. I'm using 6GV5 tubes and have the chimney caps connecting the plate voltage.
My own crude knowledge made me think that I got a bad output transformer. They were newly bought. I was hoping that someone may have an idea of what might cause the symptom of one side of a pp output to basically have no voltage that could arise from the circuitry, if they could point it out to me. My next step in crude troubleshooting would be to swap the outputs and see if it follows. Or, please let me know if there is a better way to test the output transformers.
I have attached the schematic.
Thanks for any thoughts on this.
I just finished wiring up the engineer's amp board with the recommended Edcor outputs. While trying to make the bias and balance adjustments I discovered an issue. I had checked the b+ before trying to adjust and it was okay. I could not get the left channel current test points to rise above around .355mv. I swapped the tubes around but the problem stayed in the same place. I'm getting 328v b+. On the left channel I get 298v on PLT1 but PLT2 reads negative 300mv. The plate of both 6cb6 tubes is around 155v. I'm using 6GV5 tubes and have the chimney caps connecting the plate voltage.
My own crude knowledge made me think that I got a bad output transformer. They were newly bought. I was hoping that someone may have an idea of what might cause the symptom of one side of a pp output to basically have no voltage that could arise from the circuitry, if they could point it out to me. My next step in crude troubleshooting would be to swap the outputs and see if it follows. Or, please let me know if there is a better way to test the output transformers.
I have attached the schematic.
Thanks for any thoughts on this.