RangeMaster input cap

[pigyboy]

What value of cap would give a full boost to the range master? I would like three choices, treble, mid and full.
Would .05u or .1 be enough or something bigger?

[madbean]

.05 would be plenty. Higher than that and you might get unwanted subs and stuff.

[pigyboy]

Thanks Brian,
This might be a lame question but how is it on some of the fuzz face schematics there are 2.2uf input caps? I am referring to the fulltone '69.(I think, I know I have seen it somewhere)

[madbean]

Well, that's an important question, because the stock fuzz face is definitely very bassy. You certainly do not have to use such a high value: one common mod is to lower it to 1uF. But, you could go even further down if you want. However, the flubbiness of the FF is part of the charm, I think, so it really comes down to personal preference. I don't care for the tone you get with a very small cap...it just becomes kinda sterile, IMO.

In the case of the Rangemaster, I indicated 50n for a full range boost because the input impedance is set by that 68k resistor at the front of the circuit. Using the formula f=1/(2*pi*R*C) you find that with a 50n cap and 68k resistor you get a high pass filter that starts at about 40hZ and decreases by 6db per octave thereafter (going towards 0hZ). 40Hz is actually even a little low for guitar (I think the low E string is around 62Hz), but high enough that you will not have any flubbiness or unwanted subs coming out.

Remember, though that the formulas only tell you part of the story. Your ear should always be the final judge. I found this out when I first started designing overdrives. I spent a lot of time calculating frequency roll-offs and tried to take a very precise approach. But, after actually hearing the results, I was never satisfied....there's always some tweaking