Candy Apple Fuzz: Code Red

[Chuck D. Bones]

This is reportedly Bjorn Juhl's first commercial fuzz pedal. Intended to produce all of the nasty, ripping early fuzz tones, it makes raspy, velcro, gating, farting chainsaw sounds, with a little octave thrown in. I built it 95% per the drawing, altering the TREBLE control so that it actually does something and adding one resistor. There are two versions of the schematic floating around on the 'net. The difference is the inclusion of a 1K resistor in series with C7. Without it, the gain makes a huge jump when NATURE is dimed. You can see that resistor top center in the picture below, standing vertical next to the 22uF tantalum cap. I threw in one (mil-spec) carbon comp resistor just for the Hell of it. It's far enough down the signal chain that it won't be a noise contributor.

Unlike the advertising claims, the octave behavior is very fussy and nearly impossible to find on the NATURE control. I've tried different germanium transistors. The two in the photo are Russian MП38A's. I have since gone back to the 2N1308s called out on the BOM. I'm still exploring the NATURE control, which functions as a both a balance & bias control for the octave section. I don't expect the octave to ever be as smooth as a Green Ringer. The FUZZ control has a good range of gains and the pedal is capable of outputting over 1Vp-p. Not huge, but enough to make some serious boost. the VOL control is set for unity in the pic. The BOM called out a linear taper pot, but I'll probably end up changing it to audio taper.

I have not yet bonded with this pedal. Some of you may like it; I'm still on the fence.

That monster LED is actually red, the camera wants to see it as orange. Predrilled box from Tayda. I should have stripped off some of the internal powder-coat under the pots and jacks. So far, no grounding problems.

 

[jjjimi84]

I love it but i have to ask what you did to make the treble control actually work. This is in my to do pile and wouldn't exploring some mods. I owned an original and never bonded with it, was hoping to make some changes this time around.

 

[Chuck D. Bones]

I changed C11 to 10nF and R18 to 5.1K (4.7K is close enough if you don't have 5.1K).
I also changed the VOLUME pot from B50K to B100K to reduce the volume change when turning the TREBLE control. That change does not affect the tone. If you decide to change the VOLUME pot, I'd recommend A100K.

I tried some resistor mods in an effort to make the NATURE control more user-friendly, but that's still in work so I won't report on it just yet.

 

[Mourguitars]

Purdy work CDB ! Looks awesome....

Mike

 

[PapaBear]

Nice!

 

[Mir9]

Chuck, your tone mod makes the control actually do something, thanks. Was the stock setting just at too high a frequency? I noticed no change before.

Have you tried any silicon transistors for the octave part? I've had good results with both lower and very high gain ones, but went back to the 2n1308. He had another project, the Folk Fuzz, that told you to try either 2n1306 germ. or 2n2219 for silicon.

There are also some versions with internal (trim, later made external) gate pots that looks to be placed between R15 (5.6k) and the 9v. I tried some small value ones and they work well, but the nature control gates enough for me.

 

[Chuck D. Bones]

Hmmm... Interesting.

The stock TREBLE control has a few problems. The 100pF cap is so small that it's tuned above human hearing. The 51K resistor in series with that cap is so large that the range of adjustment where the cap does work is only a few dB. The VOLUME control loads the tone control network, making the TREBLE control alter the volume.

I've been staring at the Candy Apple schematic for a while, looking for something to change to get it to do something I like. I could find one or two spots on the NATURE control that worked for me. The way the NATURE control works, the signal either flows thru Q3 or Q4. That extremely narrow range where they're both on produces some octave-up, but the gain and signal level drop way down. Eventually I came to the realization that the Pink Purple Fuzz evolved from the Candy Apple. ? Look at the two schematics side-by-side and you'll see what I mean. My next move is to delete Q4 and move a few things around, nothing too drastic. What I have in mind is something akin to the Pink Purple, but with more attitude. I've abandoned the prospect of getting this thing to do octave-up. But gating and high-gain are definitely in the picture. This project is on the back burner for the moment while I catch up on some other pedal builds & mods. Once I have something I like, I'll post it in the Modifications forum.

 

[music6000]

Nice Build Chuck!
When I see an Enclosure with this much Paint, I immediately look for ground wires on Input & Output jacks.
Too many times I see Builds with no ground wire on the output jack & I just nod my head, the Terminal is put there for a reason.
You will not see it missing in any of my Builds.
My 2 cents !

 

[Chuck D. Bones]

Thanks!
I may be accused of putting in too many grounds, but never too few. People talk about single-point grounds and ground loops. I consider the entire box a single-point ground. I'll use every ground pad and terminal provided. For a ground loop to pick up hum or noise, it has to enclose a sizeable area and that's not possible in box this size. This box really should have had some of the paint removed on the inside. Next time it's apart, I'll do that. Tooth washers don't always bite thru the paint.