20-07-2020, 03:45 PM
Agreed
A slightly leaky cap from ECC83 anode to EL84 grid? But nothing to do with the hum. I might be wrong, but I'd take out the EL84s and ONLY have in the phase splitter. Then I'd look at all the DC voltages on the ECC83 and the hum, if any, on the anodes via scope.
Note, the ECC83 (and some others) are designed for 6V or 12V operation, so pins 4 & 5 are shorted and pin 9, the centre tap, is the other 6.3V supply pin.
The Anodes are pin 1 and pin 6.
Wikipedia
Radiomuseum: https://www.radiomuseum.org/tubes/tube_ecc83.html
A slightly leaky cap from ECC83 anode to EL84 grid? But nothing to do with the hum. I might be wrong, but I'd take out the EL84s and ONLY have in the phase splitter. Then I'd look at all the DC voltages on the ECC83 and the hum, if any, on the anodes via scope.
Note, the ECC83 (and some others) are designed for 6V or 12V operation, so pins 4 & 5 are shorted and pin 9, the centre tap, is the other 6.3V supply pin.
The Anodes are pin 1 and pin 6.
Wikipedia
Radiomuseum: https://www.radiomuseum.org/tubes/tube_ecc83.html