Low pass filter help

[telewacker]

I want to put a simple low pass filter in a box with a pot, cap, and in and out jacks. How should I wire it?

[donnyjaguar]

Need more information here. Need to know the frequencies you want to pass first, and how sharp of a filter you'll need. Passive circuits are always at the mercy of the incoming and outgoing impedances so more detail will help here. Maybe describe the reason you need this device as there may be a better solution. No point re-inventing the wheel I always say.

[telewacker]

Need more information here. Need to know the frequencies you want to pass first, and how sharp of a filter you'll need. Passive circuits are always at the mercy of the incoming and outgoing impedances so more detail will help here. Maybe describe the reason you need this device as there may be a better solution. No point re-inventing the wheel I always say.

OK this is an unusual situation. I have an old Marshall 8x10 cab that is extremely bright. I have it paired with an Ampeg VL1002 head and even with the treble control all the way down it's still too bright. I put a graphic EQ in the FX loop and was able to calm down the highs sufficiently but I thought a simple low pass filter, like a guitar tone control, would be an easier fix (also placed in the FX loop). Basically I need to roll off frequencies starting around 3k judging from the graphic. I'm not sure of the input-output impedances of the loop?