Do It Yourself

Born on the Bayou: Build Your Own Kustom Harmonic Clipper

  • By Nicholas Kula @tonereport
  • November 30, 2016
  • 9 Comments

The mysteries of tone have largely been solved. The gear played by many famous guitarists is well-documented and thanks to curious tinkerers, readily available. Hendrix played Fuzz Faces, Roger Mayer Octavios and Uni-Vibes, and now there are hundreds—if not thousands—of variants on each available. When looking to solve these mysteries, the brain needn’t work hard; just look at the floor and the backline. Failing that, just use your ears. If someone is getting paid to step on an artist’s pedals for them, listen for the effect and try to parse it later. By now, most, if not all cases are cracked. However, some of these put legions of tone detectives on overtime hours, deciphering these mysteries one at a time. One such mystery was the tone of Creedence Clearwater Revival’s John Fogerty.

Coming at a time when it’s entirely possible that Mr. Fogerty employed someone to turn his pedals on and off behind the scenes, Fogerty’s fuzz tone was a mystery that stretched well into the internet age. And with so many devoted fans, the public was eager to find out.

As it turns out, Fogerty’s tone was even simpler than any of us could have imagined. Fogerty’s amp—the Kustom K200B—contained not only the swampy tremolo we came to expect from CCR, but the fuzz circuit as well. The fact that Kustoms have been notoriously viewed as “bottom-tier” amps for their entire existence only added to the denouncement of Fogerty’s fuzz tone coming from them. Muddying the waters was the fact that this particular model is extremely rare, and the only Kustom amp to feature a fuzz circuit, which Kustom called the “Harmonic Clipper.”

In all reality, the Harmonic Clipper circuit is an extremely close approximation of another extremely rare fuzz—the Sam Ash Fuzz Stainer. The one difference is the transistors. While the original Fuzz Stainer used 2n5173 transistors, the Harmonic Clipper changed directions entirely and used MOSFETs—a radical departure from anything of its time period. Today, you will create your own radical departure by building one of these rare beasts. But first, you should read this:

Disclaimer: Neither I, nor Tone Report Weekly bears any responsibility for any kind of personal or property damage that may occur as a result of the instructions provided herein. Legal mumbo-jumbo aside, we ask that readers be familiar with a soldering iron and its accompanying safety procedures before trying anything listed here. Furthermore, if you fire the pedal up and it does not work, it will need troubleshooting. Assuming the components are not damaged, the pedal will work. I built this very unit according to these instructions and it fired up, first shot, so I know the instructions are correct.

A couple notes before we launch into this badboy: I used 2n7000 MOSFETs, but these are some of the lowest-gain devices around. 2n7000s deliver a satisfying crunch with a hint of fuzz, which is how I always heard Fogerty’s tone. For more fuzz, try using something like BS170 instead. You can also socket the transistors to swap them at your leisure.

Also, the output volume of the original is low—lower than your dry guitar signal, even when turned up all the way. To combat this, I placed an excellent Escobedo Duende boost at the end. The Clipper’s original volume potentiometer was turned into a trimpot. You can then use the trimpot to adjust the volume of the Clipper before it hits the boost, which essentially adjusts the range of the volume knob.

Now let’s build that circuit board! You’ll need:

Resistors:

1x 100 ohm

1x 1k

1x 2.2k

1x 5.1k

1x 47k

1x 100k

1x 640k

2x 1m

1x 2.2m

1x LED resistor, the value of which controls the brightness. If you’re working with a clear LED, I like to make this 15–22k, and 2.2k for a diffused LED.

Capacitors:

1x 10pF (ceramic)

1x 47pF (ceramic)

1x 51pF (ceramic)

1x 100pF (ceramic)

1x 39nF (0.039uF, film)

1x 47nF (0.047uF, film)

1x 100nF (0.1uF, film)

2x 220nF (0.22uF, film)

1x 100uF electrolytic

Semiconductors:

2x 2n7000 (see notes above) transistors

1x J201 transistor

1x 1n4001 diode

2x germanium diodes, I used these cool Raytheon ones from Smallbear

Potentiometers:

1x 50kB

1x 100kB

1x 1mB

1x 100k trimpot

Miscellaneous:

1x piece of Veroboard (stripboard) cut and prepared to spec

2x three-pin transistor sockets (you can buy SIP sockets and cut them to fit)

Wire

Alright, let’s wire it up!

Step 1: Since the resistors and diodes are the same height, I’ve included them all in the same step. Bend the leads downward, insert them into the board, bend them outward, solder them and clip the leads. Save these leads.

Step 2: Using these leads, form the jumper wires. Bend them outward, solder and clip.

Step 3: At this time, insert the transistor sockets and trimpot. Place something flat over the top such as a CD case or coaster, and flip the board over to hold them in place. Solder them. Don’t worry about dialing in the trimpot yet.

Step 4: Insert the capacitors. Bend the leads outward, solder, then clip.

Step 5: Cut the transistor legs to fit, then place them in the sockets.

Step 6: Cut the wires, strip them and insert them, connecting them to the potentiometers.

That’s all! Now let’s build that enclosure!

You’ll need:

1x enclosure, drilled to accept three pots, one LED, input and output jacks, footswitch and DC jack

1x LED

1x LED bezel (same size as LED)

2x ¼” mono input and output jacks

1x DC jack

1x 3PDT latching footswitch (non-momentary)

3x knobs

Alright, let’s do it!

Step 1: Mount the footswitch, DC jacks, input and output jacks and LED in bezel.

Step 2: Run a saved lead between lugs 4 and 9 on the switch and solder lug 4. Feed the LED’s negative leg into lug 1. If the LED can’t reach, use a wire.

Step 3: This is where we ground the enclosure. Run a wire from lugs 2 and 6 to the negative lug on the DC jack. Solder the switch lugs. Then, run a wire from the negative lug on the DC jack to the sleeve lug on either the input or output jack. Solder the DC negative lug. Then run a wire from the sleeve lug to the other sleeve lug, and solder the first sleeve lug, leaving the last one unsoldered.

Step 4: The pots have a tiny metal tab on the sides that keep them from being mounted. Break these off with pliers and mount the pots and board.

Step 5: Connect all the wires to their appropriate places. The ground wire from the board goes into the as-of-yet unsoldered sleeve lug.

Step 6: Wire the tip lugs of the input and output jacks to the switch. One of these goes into the as-of-yet unsoldered lug 9. When you fire it up, use a screwdriver to adjust the trimpot. This lets you set the fuzz output before it’s boosted, which essentially lets you decide the range of the volume knob on the surface of the pedal.

Step 7: That’s a wrap! Bask in your glory!

So, what does it sound like?

I found that the 2n7000s give quite a Fogerty-esque sound, as his fuzz tone to me was about subtlety and articulation. The circuit is sensitive to pickup type, so those with single-coil axes might want to put the BS170s in there for a little more girth. It sounds light, crunchy and fuzzy when you play hard, which sums up Mr. Fogerty quite nicely. Get a load of Andy playing this beauty through his Deluxe Reverb reissue:

 

Until next time, up the irons!

 

 

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9 Comments

  1. Colin

    What value are the germanium diodes?

  2. Johnny Balmer

    Just to confirm: lug 3 of the gain pot connects to lug 5 of the footswitch? That isn’t clear in the instructions.

  3. Johnny Balmer

    Also, the photo in step 6 appears to show a B10K gain pot - even though the instructions indicate a B100K.

  4. Joe K.

    Hi, thanks for the article.  I would like to try to build this.  I have a couple of questions:

    1.Do I need more than just the parts list above to order the correct parts, or is that enough?

    2. Is the best approach to go to small bear electronics or some other supplier and buy the individual parts? 

    3. Per the other commenter, do I use a B10K gain pot or B100K? 

    4. Can I replace the trim pot with the same value pot that I mount on the outside of the enclosure?

    Thanks for the article and your time and effort.  I know I am asking a lot of questions but I want to do as well as you did in building this nice sounding pedal.  Joe K.

  5. Nicholas

    Hi guys, sorry to leave you hanging.

    1) You can use any germanium diodes. The ones I used are random parts.

    2) Yes, that’s correct. The Gain control basically acts as a gate to let more of your guitar’s signal into the circuit. I admit that adding that is an oversight, but at least it was in the schematic.

    3) I used a 10k pot originally (for the photos) but after I wired it up, 10k had very little effect. I changed it to 50k in the instructions for a more dramatic effect, so you wouldn’t make the same mistake I did.

    4a) Everything you need is listed.

    4b) Yes, that’s pretty much the only way to do it.

    4c) The Gain pot is always 100kB. It’s the Bias pot I changed, to 50kB.

    4d) The trimpot only determines the range of the Volume control, so making it external is kind of a waste. If you want to omit it entirely, put a jumper between rows G and H on column N.

  6. Billy James McKnight

    This looks very much like pink jimi photons work! nice that you do a DIY project not so nice you don’t credit the man that actually came up with it originally on Aron Nelsons DIY stompboxes forum!  The man does a whole lot for us DIY guys for free so jimi should be credited I think at the very least

  7. Felipe Ballarin

    Hi Nicholas,

    Just pointing out that is not the Sam Ash Fuzz Stainer, the schematic above is a Mosfet take on the Sam Ash Fuzzz Boxx, that is similar to the Astrotone Fuzz. The Fuzz Stainer is a diferent Beast, there is no diodes to ground cliping, there is a feedback path from Q2 to Q1 like the fuzz face, diferent tone control, etc.
    I’m not trying to be an ass here, just correcting the reference name.
    And thanks for the article =]
    This kind stuff keep us DIYers going on!

  8. François

    Thanks for this awesome schematic !
    I’m currently ordering parts to build this great effect and it appears that 51pf capacitors are not easy to find here. I guess this is not a current value :(
    Do you thing it can be replaced with a 47pf or even 56pf one ?

  9. pink jimi photon

    yep. my circuit. right down to the values and shit.
    my circuit started off based on the harmonic clipper of the kustom 200 guitar amp.
    what you’re building here as “nick’s” project is actually mine outside of him screwing up one connection (you can get the proper thing on tagboardeffects.blogspot.com) right down to the cap values and kinda of fets used.
    its not the kustom schematic. not even close. but it is indeed very much identical to mine, which i gave to the DIY community to use, with no commercial use allowed.
    i contacted tonereport about this, as did dino tsiptsis who helped me cobble the thing together initially. they were asked to give proper credit, but never did.
    they did offer an “ad” in their publication, but i am not a commercial builder and asked instead that they run a free ad for aron nelson’s diystompboxes.com, where the circuit was taken from by nick (google the actual schematic, and compare the original circuit to mine, then look at what nick appropriated.)

    not very cool. you guys should be better to us guys who do all the fucking work, without us and our labors, you wouldn’t have shit to pimp in the first place, and people wouldn’t have anywhere near the tonal options that they do.

    an apology is one thing. carrying on the charade that this is nick’s work is another. it’s not.

    no love at all
    pink jimi photon