markbul
09-04-2006, 01:40 AM
I stuck a 6SJ7 in the first stage of what is basically Mark Huss' Plexi 6V6 design.
6SJ7 -> vol. pot -> 12AX7 DC into cathode follower -> MV -> PI
There's a sharp buzz that gets louder as I turn up the first vol. pot. As it gets louder, a low hum shows up under the buzz, and also gets louder.
The heaters are grounded thru 2 100 ohm resistors, referenced to about 36V.
The input jack, first vol. pot and preamp cathodes and filter caps are grounded to a star near the isolated input jack.
Question: since both noises get louder with the first pot, can I assume that the problem is getting in the circuit between the input and the pot?
6SJ7 -> vol. pot -> 12AX7 DC into cathode follower -> MV -> PI
There's a sharp buzz that gets louder as I turn up the first vol. pot. As it gets louder, a low hum shows up under the buzz, and also gets louder.
The heaters are grounded thru 2 100 ohm resistors, referenced to about 36V.
The input jack, first vol. pot and preamp cathodes and filter caps are grounded to a star near the isolated input jack.
Question: since both noises get louder with the first pot, can I assume that the problem is getting in the circuit between the input and the pot?