low pass filter/ effect loop/ anti-fizz question

[freakshow__]

hey all

SO...here's my dilemma and idea...sorry but this is 1/2 amp related and 1/2 effect related

I just bought a mesa dual rec. and like the amp BUT...the red/orange channels just have WAY too much fizz for my taste. I have heard some people mod amps and add "anti-fizz" switches to them to fix amps like this etc...

My idea is this: To make a low-pass filter and throw it in the effects loop of the amp to attenuate the horrible presence the amp is projecting...it's actually quite deafening after a while. (fyi the amp has a parrallel effects loop)

Anybody here know what values are good to start with for this expieriment? I only want to get the really high frequency stuff out here. Any help is very greatly apprechiated! Thank You!

[freakshow__]

for anyone interested....

I succesfully tamed the treble with a very simple lowpass R-C network

Used a 50k pot for the resistor part and a .0027 uf for the cap  and it gives me more than enough range to zero-in on the sweet spot. Enjoy!