Fuzz Face Tone Control?

[phillip]

I ran across one of Analog Man's 4-knob Sun Face pedals on eBay, so I went over to his site to get the scoop since I noticed that it had a tone control:

The forth knob is a TONE knob but with a twist. There is a mini-toggle switch below the TONE knob. In the UP position, it acts like the TONE knob on your guitar. But if the fuzz is up high, your TONE knob does not do much. So we added the DOWN position which puts the tone circuit AFTER the fuzz for a more pronounced roll off of high end. But since simple is better and sometimes you don't need to roll off the tone, we also have a MIDDLE position which totally bypasses the tone control.

After mulling over that for a while, I came up with something that might work similarly to Analog Mike's:



Does anyone have any insight on how well that would work?  The two capacitors in red might need to be adjusted to get the tone control to function properly.

Any thoughts?
Phillip

[brett]

Hi
I think that the schematic and values look good for the output control, but I don't know about the input side.  It will depend on the high output impedance of the pickup.  

FWIW, I think it's the output side you want to control, anyway.

[brett]

Oops!! Didn't look closely enough.  The output tone control has to connected BEFORE the level control (otherwise the extra, variable output impedance will move the pole frequency when you change the level)

[phillip]

EDIT:  I made a smaller schematic, corrected the connection to the Volume pot, and I also rearranged the tone control setup so that the capacitors on the input and output can be altered independently.  I made the input tone control capacitor 0.047uF and the ouput tone control capacitor is still 0.01uF.

This tone control setup is like the one used on the Les Paul, with the capacitor before the tone pot, connected to the wiper, and lug 1 of the pot grounded.  I set it up so that the switch opens the side of the capacitor that won't cause unpleasent pops...at least I don't think it would pop wired like that.

Phillip

[AL]

Phillip, Oskar Bruil has an input cap blend schem floating around the web somewhere. It involves a pot and a few caps on the input. It works OK (I think a switch may yield better results). I have one on a FF that I built. It does take some of the growl out of the FF which, while disspointing in some respects, works really well (for me) as a lead boost. With the one I built I think it is very necessary to be concious of what amp/guitar combo you are using and definitely socket the caps.

AL

[phillip]

I tried the input cap blend setup a while back on the Fuzz Face circuit, but I wasn't very fond of it because of the fact that it did change the sound of the circuit somewhat.

I thought I'd get some ideas on this setup since I got the idea from reading the Fuzz Face page at Analog Mike's page.

Any other ideas anyone?
Phillip

[Hal]

doesn't the easy face use something like this - an input cap blender, as a tone control?

[phillip]

Yep several of Joe G's circuits have the input cap blend tone control.  That's the one that I tried before, but I didn't like it too much.  The tone control in my schematic above is a simple lowpass filter, like the kind that are used for guitar tone controls.

Phillip

[lightningfingers]

Phillip, Oskar Bruil has an input cap blend schem floating around the web somewhere

I have that one on my ff, I do like it (the stock setup has too much bass for me) but it decreases the drive quite a lot as it trims off the bass.

One other thing, the mod on Oskar Bruils page calls for a 100K pot-this is too big. I ended up using 25K before it started to feel linear.....

EDIT: don't mean to hijack the thread, but did anyone try the blend pot on the output?