Multiple high-gain circuits in one enclosure - precautions?

[80k]

I'm about to box up 3 of my favorite distortion/fuzz circuits into a single enclosure (crossover distortion, ProCo Rat, and Muff).

I will be grounding the inputs to each effect on bypass. Additionally, though I currently have them all sharing the same power line, I think I will go through the effort of decoupling the power (adding a series 47 ohm resistor and a 100uF electro after it to ground) for each of the 3 effects. If I do this, should i still add a 100uF electrolytic at the 9V DC jack?

Are there any other precautions or steps I should take to reduce the chance of any problems that might result from this project? I have tested the board already, but have not boxed it up yet.

[ninjaaron]

won't series resistance decrease the voltage

[80k]

won't series resistance decrease the voltage

yea this is one of the drawbacks of this method of decoupling.

[JKowalski]

If you have them on separate boards, maybe you can develop a way to shield them from each other? Maybe metal dividers between the boards?

[80k]

If you have them on separate boards, maybe you can develop a way to shield them from each other? Maybe metal dividers between the boards?

Unfortunately I have them on the same board, and the way I have components on there, it is nearly impossible for me to split it up now. Otherwise, it's probably worth doing.

[Sir H C]

This is where shielded wires can be useful, especially if you can have the signals boosted all in a row.  Also look at a 1nF or so cap in parallel with teh big electrolytic, keep that impedance low at high levels.  Star grounding would be good, look at each ground separate to the jack, even if cutting ground traces is required to do this.  Also putting said ground wire on the output side of the ground trace.  Keep the 100uF on the input jack, then you have another filter pole from effect to effect.

[80k]

Great ideas there, thanks. I don't have shielded wires at the moment, but will be easy enough to add later if I decide it is needed. I should be able to star ground this by simply cutting a couple traces and adding a couple wires.

I think the Rat circuit already has a small cap in parallel with the 100uF electro. I will add a 1nF cap in parallel for the other two circuits.