Fender grid caps

[J Rindt]

Each 6V6 grid has a 1200pf cap to ground. Can you guys tell me what they do exactly...?
Thank You

http://www.el34world.com/charts/Schematics/files/fender/deluxe_reverb_boost_schem.pdf

[chocopower]

Some kind of cure for oscillations.
Those caps send to ground the high treble frecuencies.
With a clean layout, they are not necesary in that amp.

[LooseChange]

When working on an amp that has these, I usually lift one at a time to see if I can remove them. So far I have not had an amp that had a problem with these removed. (So far.)