I have been trying to implement George's powerdrive on my 6sn7/300b amp. I finally got everything wired up last night. I did one channel - gave a listen - and then did the other channel.
Fired everything back up and now neither 300b is idling. There is maybe a volt across the 880ohm cathode resistors.
After reviewing the Tubelab site - I am basically working off the TubelabSE schematic - I notice that there is no cathode resistor for the power tubes. Is this correct?
I am using values exactly specified on the TubelabSE schematic. For the negative rail I am getting -230V and b+ was 390 before this.
The only difference is the MOSFETs I used...I went with IRFBF30PBF.
I double checked everything and not sure where I went wrong. I may put it back to non powerdrive just to make sure I didnt fry the tubes...
Fired everything back up and now neither 300b is idling. There is maybe a volt across the 880ohm cathode resistors.
After reviewing the Tubelab site - I am basically working off the TubelabSE schematic - I notice that there is no cathode resistor for the power tubes. Is this correct?
I am using values exactly specified on the TubelabSE schematic. For the negative rail I am getting -230V and b+ was 390 before this.
The only difference is the MOSFETs I used...I went with IRFBF30PBF.
I double checked everything and not sure where I went wrong. I may put it back to non powerdrive just to make sure I didnt fry the tubes...