Tweed Deluxe preamp voltage problem

[Curbdog]

I have an issue where the plate voltages on the input tube of my Tweed Deluxe project are higher than on the subsequent pre-amp stage and phase inverter. They are at about 297v with a B+ of 300v. On the subsequent pre-amp stage and PI they are at about 200v and 160v, also with a B+ of 300v because in the Tweed Deluxe, all preamp voltages are fed from one node of the power supply. Why would they be higher on the input stage? My instinct is to just rebuild the first stage and replace the socket, rewire the input jacks, and replace all the pots and wiring to the second stage, but I thought I'd make an inquiry here before I did all that. What might be causing this? Thank you

[jelle]

My guess is that the first tube is not drawing current. Is the cathode grounded?

What is the voltage drop across the plate resistor of the first stage?

Jelle

[David Root]

Check your ground connection on that stage, probably a bad/no solder joint. The plate is at or near B+ because the tube's cathode is not referenced to ground, therefore no current can flow.

[Curbdog]

Thank you - the culprit was a 820K cathode resistor where an 820 ohm resistor was called for. The amp now works !

[jelle]