Tube Amp Archive

Like any other screen node dropper or choke it lowers the the screen supply voltage when the average screen current increases - with a bit of delay due to the filter cap. A real screen resistor immediately reacts to screen current peaks by increasing its voltage drop, thus causing NFB and instantan...

Good question. I guess that they wanted to limit the total current thru each side of the OT and those two screen resistors let them do that while still having only one bias setting on pin 5 for all of them. Steve.... But it is odd how the resistors were used. And why not pick a different value and ...

Roe wrote: ↑Sun Oct 12, 2025 9:28 am Look a the big shared screen resistor that reduces voltage and current. Looks like 400R here

Roe: Peavey uses a similar 400 Ohm resistor in many of it's amps. But unfortunately, that does not explain the inconsistent usage of the 100 ohm resistors. Thanks.

Roe wrote: ↑Sun Oct 12, 2025 9:28 am Look a the big shared screen resistor that reduces voltage and current. Looks like 400R here

Roe: Peavey uses a similar 400 Ohm resistor in many of it's amps. But unfortunately, that does not explain the inconsistent usage of the 100 ohm resistors. Thanks.

I just finished recapping a Peavey Mace 320T. I replaced some resistors as well. The amp is working fine. Why-oh-why did Peavey use two 100 ohm screen resistors for three tubes? It's as if one of the tubes is not protected and seeing the full screen voltage. I have seen some videos on Peavey amps, m...