Grid and screen resisters ?

[catnine]

I have read some people put them on amps that never had them like stating that on  princeton with the 1k dropper if the screen fails on the 6V6 then the 1k dropper with save the amp and that grid resisters 1.5K are only for RF interference.

 I put the 470 ohm screen resisters on both my builds the SF champ build and the P-P 6G2/5E3 and also put the 1.5k grid resisters on both. any harm in doing this? Both fender stock amps and the 5E3 had the 1.5k grid stoppers but none had the 470ohm screen resisters The SF champ had neither.

[phsyconoodler]

No harm but it may suck the volume from the amp. Most 5E3's don't have enough voltage to hurt the screens anyway,so it's pretty much not needed there.
 The Siverface Champ screens are fed after the dropping resistor(1k) so again,not needed there either.

Some people put them on Princeton and Princeton reverb push-pull amps and again,they have screen resistors on the board already.
  There is also no need for grid stopper resistors if the amp doesn't oscillate.They are a band-aid fix for an unstable amp.The 5E3 can get that way,so they may very well be needed on that circuit.
  I don't use grid stoppers unless they are needed,then I start with 1.5k.
Gris stopper reistors on the output tubes are NOT for RF,they are to stabilize high end oscillations.The input grid resistors are to stop RF.

[catnine]

I only put the grid stoppers and screen resisters on my 6G2 /5E3 build because I used both 6V6's or 6L6's in the out put section and the voltages on this build are much higher than a 5E3 and since the layout is like the 5E3 . Both the 6G2 and 5E3 had the 1.5k grid stoppers so I though they were there for a reason.

 On the SF champ homebrew I added the screen resister hoping to get the screen lower than the plate voltage. I added the 1.5k grid stopper just as a matter of course. On the SF champ it's board is layed out just like a SF champ yet it is a tweed narrow panel chassis . Never noticed any high end oscillations. I never noticed any loss in volume after I put them in.

[HotBluePlates]

HBP has left the building.