PSU dropping resistor question

[iknowjohnny]

So last nite i got the new amp up and running, but there are a few tweaks i need to do because tho it's a clone of my last amp, this one has a PT with more voltage. So one of those tweaks is adjusting the preamp voltage. I'm ok with it as is, but the V1 voltages are possibly higher than i like. But i'm not sure and need to try adjusting that and listening over time. Problem is, unlike my last amp this one has all the preamp caps in a single multi can mounted under the board, so changing the resistors would be a major task. I could leave length on the wires, but i don't want a lot of extra B+ wire running next to sensitive areas, so i want them short which makes pulling the can impossible w/o removing the board. So heres the question....is there any reason i can't add a resistor AFTER the node at the plate resistors? In other words it would go cap and resistor>second resistor>plate. So the cap would be separated from the plates by a second resistor if i add one to drop the voltage. I'm not sure if it matters as long as the cap is there before the plates, but unlike normal it will be separated from the plates by that second dropping resistor. I can do this because the wire going from the last node to the plates is accessible because it comes up thru the boars and soldered to the turret above the board. So i can add the resistor there. Is that clear? If not i could edit a schematic and upload it.

[Phil_S]

Not sure I follow...if the extra R is after the cap, it is in series with the plate load resistor. It is then added to the plate load and is not a dropping resistor. It will form a voltage divider and could affect the signal you take from the plate to the next stage's coupling cap.

When you increase the value of the plate load resistor, you are re-biasing the tube. There are some practical limits here and the higher you go, the more noise you will introduce. Since plate load resistors are typically 100K, your extra 10K (just guessing for conversational ease) isn't a significant change and a 1K is really nothing at all.

Why not just change out the plate load resistor? Make it anything up to about 220K and see what happens. You may also want to increase the cathode resistor when you do this. See the attached chart for guidance.

[iknowjohnny]

Doh, you're right. I should have looked at a schematic when envisioning this and it would have been apparent. Thanks for pointing our my, as Homer once said, "moronicy'.