Plate voltage low, how to raise it?

[sonofmickel]

Newbe question.....
This is for the second stage 100k plate and cathode 820r/25uf.
In the AB763 fender schematic there is B+ of 410 and plate voltage at the tube 270v and 2.1v at the cathode.
My amp stock: B+370v
Plate "r" 100k, 207v at the plate and 1.3v at the cathode.

Plate "r" 50k, 260v plate and cathode 1.6v.

The notes seem "snappier" with the 50k/higher plate voltage, while the notes are smoother with the 100k/lower plate voltage.

Would this be bad for the tube?
The solution is probably math

[Roe]

reduce the values of the power resistors in the dropping string, and increase the value of the filter caps to keep the same amount of filtering

[Stevem]

Is this in a Fender amp , or in a build?

Fender uses that 820 resistor due to it powering two cathosde triode sections, if you are only powering one section than for proper tube bias that 100k plate load resistor needs to be dropped to 50k!

The rule of thumb is a 25% range with platel load or cathode resistors, so in light of this I would not go any lower than some 75k with that 820 ohm cathode resistor.

[Littlewyan]

820R on the Cathode with 100K plate resistor isnt a problem, Marshall use this on two stages in their 1987 Amps. You could try raising the cathode resistor to 1.5K or even 2.7K for snappier notes. Probably the easiest thing to try.

[sonofmickel]

I ended up going with 100k Plate, 1.8k/25uf cathode. 248 plate, 2.08v cathode. Sounds good and clean. Thanks for the help.