tweaking a Foxx Tone Machine clone.

[Keysershades]

Hey folks! I just got this Foxx Tone Machine Clone and it's really brutal and cewl!
Not as good as the original but i think it will be good when i get some NOS BC109 in it!
But the tone knob is just useless, it's either to muddy and "bassy" or way to sharp and unpleasant.
I'm not that good with modifying pedals i usually just repair but shouldn't it just be changing the tone caps with some propper ones ?
And if, can anybody point out to me which ones that forms the tone ? And which to change ?

Sorry if my grammar is way of, I'm from Denmark... The capital of Sweden.

Simon

[Keysershades]

http://www.geofex.com/FX_images/foxxfuzz.gif

Thats the schematic i wanted to post but forgot

Simon

[theehman]

Why BC109?  The original had 2N3565 in it.

[bumblebee]

I found it sounds better with BC109C's in it myself, that's whats in mine. I didn't like the 3565;s as much.

[trjones1]

The Tone Machine uses a Big Muff style tone control, so you could try AMZ's presence mod:
http://www.muzique.com/lab/tone3.htm

[Mark Hammer]

Actually, the TM tone control is a little different than the BMP.

The simplest route to getting a different treble/bass balance is to increase the value of that .03uf cap shown in the tone circuit to a slightly higher value.

[Keysershades]

But the tone cap in my clone isn't a 0.03uF but a 332M. That's kind a waird then ?`Or am i being a totally newbie ?
About that AMZ tone control, i just swop the tone cap with that circuit ?
And for the change of transistors i only bought two BC109, did not realize that there is 4 transistors in the Tone Machine. All four of them creates the fuzz ? Or are two of them for the octave ?
Stupid me, Simon.

[Keysershades]

And another thing, is it possible to just bypass/cut out the tone control and get a more pure fuzz face like fuzz ?

[Mark Hammer]

But the tone cap in my clone isn't a 0.03uF but a 332M. That's kind a waird then ?`Or am i being a totally newbie ?
About that AMZ tone control, i just swap the tone cap with that circuit ?
And for the change of transistors i only bought two BC109, did not realize that there is 4 transistors in the Tone Machine. All four of them creates the fuzz ? Or are two of them for the octave ?
Stupid me, Simon.

You're correct actually.  I was looking at a crudely drawn schematic and should have consulted others.  Of course the capacitor is 3300pf (AKA 332, .0033uf, 3n3, etc).  My spidey senses should have tingled when I typed out .03uf, which is way too high to do the job.

Consider swapping in a 4700pf (472, .0047uf, 4.7nf, 4n7) for the 3300pf unit to get a little more upper mids in the treble tone.  The simplest thing to do is to temporarily tack on an additional 1000pf (.001uf) or 2200pf cap in parallel with the existing cap, rather than removing the one you have in there.  You can temporarily solder the leads of the additional cap on to the copper side, give it a listen and decide if it does what you need or not.

For the bass side of the tone circuit, it gets a little trickier since we can't lower values by adding something in parallel.  With that complication in consideration, if you were to replace the .05 (.047, probably) cap on the bass side of the tone circuit with a smaller value, like .033, or .022uf, you move the rolloff point up a bit and include a little more lower mids and vocal tone in with the signal when the tone control is rotated fully bass-wise.

[Keysershades]

Great! Thank you! But can you answar any of the other questions ? About the transistors or the bypassing of the tone ?

Simon