Input stage grid stopper install question.

[dragonbat13]

I am working on a two channel, dual input for each channel, stock fender vintage 1966 bassman (AB165).

I want to add some grid stoppers to the input grids on each channel.

My question is how to do it. I've read a lot of stuff about how it works and all, did some searching, but could not find any info on what should actually be done. Should I move one of the 68K resistors from a jack, install a jumper wire in place of it, and install that resistor at the tube grid? Or should I leave them as is and add another resister all together? If the latter, what value? Once I find out what value I plan on reading and learning exactly what changes the added resistor does to the circuit besides reject interference.

I also plan on adding a cap to ground on each channel as I have read in some places.

Thanks for the help.

[martin manning]

A concise explanation of what the grid stopper does is here: http://www.valvewizard.co.uk/gridstopper.html
A properly located stopper (at the tube pin) is incompatible with the Fender Hi-Lo jack setup. You could add a small stopper at the grid pin, keeping the existing arrangement, but I don't see the need. You could just leave the two 68k's on the jacks, and replace the existing wire with a piece of shielded cable, grounding the shield at the input jacks only. That will add a bit of capacitance to ground, and provide some RFI shielding.