Fuzz Face tone control. Nobody thought of this?

[Morocotopo]

Coool!

Paint is a pain in the a$$



I´m gonna try your version of the Mod marcelo, see how I like it. Report later.

[nek314]

Hey, I stumbled on this thread yesterday while trying to find a novel tone control for my FF. I had the Dunlop JD-F2 reissue version and had heavily modified it over the years, but it still wasn't cutting it at all. It was muddy and had barely more than unity output with everything maxed, so I decided to totally rebuild it using the Axis Face PCB layout from Fuzz Central. I was going to reuse the Ge transistors and, of course, the enclosure, but came to find out that the trannies I had were ridiculously leaky and too high gain to boot (which was probably most of the problem,) so I went with a couple NPN Si I had laying around with gains of about 80 and 140 for Q1 and Q2, respectively. I used Marcelo's tone control with a 1kB pot and 47 nF cap initially, liked it, but felt I needed to be able to roll back more high end (I had also decreased the input cap to 1 uF, the emitter bypass cap to 10 uF, and the volume pot to 100kA, making the whole thing thoroughly more trebly,) so I changed the tone cap to 100 nF and that completely hit the spot. I had been using the SWTC, but it was loading the output far too much for my liking. Marcelo's design (and, of course, Ariel's initial concept,) is ingenious: instead of simply dumping highs after the fact, it adjusts the gain of the higher frequencies, much like a Dallas Rangemaster. It has significantly less impact on the output level. Also, in place of the fuzz control, which I've always found basically useless and just hard-wired on at 1.5k, I used the Fulltone-style "smooth" control, 100kB as a variable resistor on the input. Simply put, it's super useful, when you roll it back you get great backed-off cleanish fuzz that you can set and have available when the effect is switched on, rather than fiddling with the guitar's volume, though that also has a good, wide range of effect on the sound. Add in an outside-accessible bias trim pot and sockets for the trannies and caps and I have the most versatile, sweet-sounding fuzz I've ever played. Not only that, but it has loads more output than most others I've tried. Usually you have to dime the volume and fuzz to get anywhere near enough volume to cut through a mix. All of this just confirms, in my very humble opinion, that the fetish for Ge transistors, despite their leakiness and temperature instability, is more about just knowing they're in there than any inherent sonic superiority. Of course, I do not have "golden ears", so salt that however much you like.
Long story shortened slightly, a big thank you to Ariel, Marcelo, Mike Fuller, Phillip Bryant, and the venerable R.G. Keen for his ever-enlightening Technology of the Fuzz Face article from which I drew most of my inspiration.

[mac]

NOte that this high cut control can be implemented on all collectors/drains, or emiters/sources in buffers.

mac

[nek314]

Yeah, I guess it's been staring me in the face in the Big Muff's base to collector bypass caps, maybe it would be interesting to implement this idea in the Muff and forgo the traditional tonestack which I've never liked.

[mac]

Yeah, I guess it's been staring me in the face in the Big Muff's base to collector bypass caps, maybe it would be interesting to implement this idea in the Muff and forgo the traditional tonestack which I've never liked.

Add the Axis Face bass control at the front.

Or you could try the tonebender 3 tone stack   
Just replace the 15k on any of the first 3 stages with a 18k + 4k7 and add the rest of the tone control parts. If you take a look at the TB3 schem you'll figure it out.

mac

[nek314]

Next on the old breadboard: a muff, possibly just the first three stages, minus the normal tonestack, sustain wired full-on and I'll try these tone control ideas, see how it works out. I've been wanting to make something smaller and simpler than my frankenmuff, good as it is.

[joegagan]

wow,cool,  you are getting very close to our experiment from 2010. we wired the sustain knob full up and got rid of the tone stack and a few other things. it sounded very good to me. i have a few vids and a schematic on this thread: ( didn't mess with the tone at the diode/cap loops tho)

http://www.diystompboxes.com/smfforum/index.php?topic=83920.0

[Morocotopo]

Nek, glad you got some use out of this! I implemented this in a Fuzz Face, and later made another one with the Big Muff tonestack, and this highs filter sounds so much better than the Big Muff one, at least to me.

Mac, I just built a Tonebender MK III. Super cooooool!!!! Now, I´ll add the MK III tonestack to a Fuzz Face, to see how it works.

[mac]

wow,cool,  you are getting very close to our experiment from 2010. we wired the sustain knob full up and got rid of the tone stack and a few other things. it sounded very good to me. i have a few vids and a schematic on this thread: ( didn't mess with the tone at the diode/cap loops tho)

Joe, that's sick!!!   

You could omit the recovery stage to simplify things even more, although gain will decrease a bit.

Mac, I just built a Tonebender MK III. Super cooooool!!!!

TB3, one of my favourite fuzzes.
I'm working again on my simplified silicon version, stay tuned.

Now, I´ll add the MK III tonestack to a Fuzz Face, to see how it works.

jaja buena idea!!!


mac

[joegagan]

Joe, that's sick!!!   icon_eek Cheesy

You could omit the recovery stage to simplify things even more, although gain will decrease a bit.

thank you!
yes, that was suggested by several people back on that thread but i really liked the hot output level. still surprises me how much i like the tone and sustain on those videos even two years later.

[GGBB]

So it goes from "not cutting highs at all" to a variable amount of cut? Is that right? In essence, a tone control with more range?

Yeap. I used a 47nf but can be increased to 100nf to cut even more highs.
Here is the schem (have you ever tried to draw schems using Paint?  )



mac

I was looking at this and also at the Stupidly Wonderful Tone Control 2 being discussed in http://www.diystompboxes.com/smfforum/index.php?topic=97858.0 and I am confused.  How is this (above) a treble-cut control when the SWTC2 is a treble-boost control.  They look like they are doing the same thing to me, but I am not well versed in these things.  Can someone enlighten me?

[mac]

In my schem, when the pot is on the right side (connected to the 8k2 resistor), the 0.047uf cap is a low resistance path for high frequencies to Vcc, and since the battery resistance is very small, to ground. The other path is through the 0.01uf cap, but it has a bigger impedance.
When you set the pot to the left side the cap is shorted, no treble cut at all.

mac

[GGBB]

Thank-you mac.  I didn't know that the + battery connection could function as a low resistance path to ground in this manner.  I've learned something new - yay!  Now it makes sense.  Would using a power supply instead of a battery change things at all (i.e. do typical 9V pedal power supplies have a low internal resistance similar to a 9V battery)?

[liquids]

That axis face schematic needs a serious re-draw.  It's like trying to read english characters written top to bottom.  Borderline not worth the effort.

Anyhow, just to throw another orange at the wall - consider active 2-pole low pass filtering.  It's much different sounding than passive filtering.  You can only get so much attenuation of high frequencies with a passive filter of any kind.  I entered the stompbox building world because I was tired of distortions that had a high end that could not be dialed in properly.   

Active filtering - namely, 2-pole LPF with a variable cutoff frequency rather than variable amount of cut - often seen in it's core essence in 'speaker simulation' but with a static cutoff frequency, maybe some peaking, and cascaded (values should be tweaked, LTspice is worth the time to learn), can be much more subtle in how it shaves the fizzies, or smooths things out, and to boot, it can be configured to have absolutely no effect on the audio range, all variable via a dual gang pot (for example)!!!

[mac]

Would using a power supply instead of a battery change things at all (i.e. do typical 9V pedal power supplies have a low internal resistance similar to a 9V battery)?

A few ohms will not make much difference.

mac

[GGBB]

A few ohms will not make much difference.

Thanks.