foxx tone machine mods??

Started by deaconque, April 10, 2008, 08:32:39 PM

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deaconque

i threw together one of these today according to the layout at GGG, except i used 2n5089's in it. my problem is this, the pedal sounds pretty good as is but when i turn on the octave setting the sound gets very bright.  it's so bright that i have to have the tone knob all the way down to be able to tolerate it.  is this the way it's suppposed to be?  i've triple checked everything on the board and all my connections and soldering, everything's kosher there.   

deaconque


bumblebee

ya the octave is pretty intense on the FTM.
i used BC109C transistors in mine.

Pushtone


Yes your pedal is working right, your just not using it right.

The secret tone is achieved by using the neck pickup with the guitars tone control tuned all the way down.
The the FTM octave will produce a nice 60's synth-like tone that way. Try it.

Same thing goes for the Ampeg Scambler.

For kicks follow the FTM with a gainy pedal like the BSIAB or HWY89.
I really like this sound for classic rock solos.

Dave.
It's time to buy a gun. That's what I've been thinking.
Maybe I can afford one, if I do a little less drinking. - Fred Eaglesmith

deaconque

i figured that's the way it was supposed to sound (been reading a lot of forum posts on the FTM).  i was just wondering if there was any way to mod it to where you wouldn't have to switch pickups and roll the tone down to get a better sound. 

alex frias

Well, if you use a high frequency roll off thing at the input of FTM, like a small cap going to ground, you can mimic the tone control turned down on your guitar. It works better for FTM than Octavias.

But even some specific EQ, in my opinion, is not as eficient as using of neck pickup, if the purpose is to get a more proeminent octave up effect. I think great part of the beauty in FTM is how it responds to the guitar controls, pickup switches and playing techniques.
Pagan and happy!

Mark Hammer

Like too many octave-up devices, there is no way to tailor the signal feeding the octave-generation circuit, only for tailoring the output.  That's why you get advice to work with the guitar controls.  On teh other hand, the output-tailoring may be all that you need.

To my mind there are a couple of things you can do.  One of them is to change the tone when you switch to octave mode.  You will note that "octave mode" consists of completing a connection between one of the rectified copies of the signal coming off the phase-splitter (the second transistor into the circuit).  If you are accomplishing that switchover with a toggle, consider using a DPDT (or DPST if you have one) toggle to not only complete that connection, but to simultaneously connect a cap to ground in parallel with the clipping diodes used to produce the fuzz.  You can start with .01uf and work from there (smaller = less treble cut, larger = more).  That should permit you to trim some of the additional fizz that comes with generating frequency doubling.  I don't think it is the exact same thing as starting out with a signal that is "rounder" and has more high end trimmed off, but it accompishes what you currently use the tone control for.

petemoore

  Pre-gain could be used to duplicate guitar volume rolloff, a guitar pickup controls system [with tone control] could even be used, and would mimic the guitar settings you like [if the guitar is connected directly].
  But I would probably leave the tone control as set [1 less knob 8)]or choose two tone settings Via switch.
  Rolling off some of the highs at the input via LP filter cap there seems to help smooth out octave tone also, experimenting with LPF rolloff points along the signal path = various results, and is generally easy to try...use testclip wire from ground to cap, testclip wire from cap to...testclip or wire hook...whatever allows easiest connection to signal path..insterting a LPF on the input signal, at the circuit side of the BP switch is very easy / non intrusive.
Convention creates following, following creates convention.

deaconque

thanks guys.   that's the kind of info i was after.

Stratomaster

If you used a 3PDT for switching the octave, you should have an extra set of lugs.  Use that to bypass the tone potentiometer with a fixed value resistor of your liking.  That's how I'd do it.  It would give me the tone control to be used as normal for the fuzz tone, and a usable octave tone at the same time.

-OMJ