At the time of this post, original Klon Centaur pedals are selling for thousands of dollars on sites like eBay and Reverb. I’m not about to go buy one of them, but I’ve wanted to try building a replica for a while now.
What is the Klon Centaur? Where did it come from? Why is it interesting? Since there are many good explanations out there on the innertubes, I’ll avoid spouting off about it here. Try this one:
As for replicating a Centaur, sufficient information is available on the innertubes. Here are two resources I referred to for this project:
Note: the schematic on the Electrosmash site doesn’t show the polarity of the electrolytic capacitors, or the proper orientation for the potentiometers. I got tripped up by that during my first build – I didn’t think about the orientation and I wound up with the Gain and Treble pots wired backwards.
Here is an action-packed video of the Klair de Klune:
The video demonstrates the Klair de Klune driving 1) the input stage of an overdriven guitar amp, and 2) driving a distortion pedal which is connected to an amp set to clean. As you’ll hear, it can fry really hard when asked to. That’s me playing guitar – please keep in mind that I am not exactly a virtuoso.
In the video, the distortion pedal is something I make under the auspices of my side business TH Audio. Shameless self-promotion? Who, me? Surely you jest! I figured it was better to do that than have someone else’s product there. Maybe it doesn’t matter, I dunno.
There are quite a few clones and variations of the Klon Centaur. Type ‘Klon clone’ into a search engine and you can keep yourself busy for hours. I own two of them: the J. Rockett Archer, which I like, and the RYRA Klone, which I also like, and which I guess is ‘officially’ named The Klone. Does that mean I should call it “the RYRA The Klone”? Mysteries abound.
ANYWAY, my first properly-built Klair de Klune (above) sounds pretty much like the RYRA The Klone and the J. Rockett Archer, which, predictably enough, sound like each other. Does that mean that all three pedals sound like an original Klon Centaur? Honestly, I have no idea, because I don’t own an original unit.
The photo above shows my first Klair de Klune attempt. As you can see, it had some issues.
Schematic for the Klair de Klune pedal:
Note: there are several variants of the Max1044 charge-pump chip (IC1 in the schematic above). I know that the CPA variant works because I put one in the Klair de Klune (I have some that I got for an an older project). I don’t know about the EPA or CSA variants or others. Someone else might have more insight into that.
Another note: I found some 1N34A Germanium diodes for this project (D2 and D3 in the schematic) but I don’t know what sort of variation there is among existing stock. A pair from a different batch might sound different – I can’t say. Using Silicon diodes for D2 and D3 would could change the sound noticeably, but I haven’t tried that yet.
Layout for the Klair de Klune (suitable for printing):
Note: You might notice that the layout above is different than the layout in the photos. That’s because I made a couple of corrections after I built the pedal in the photos. The boards available from OSH Park use the layout you see in the PDF above.
Another note: the Gain pot is dual-gang. On the schematic, it is marked accordingly.
BOM (Bill of Materials) for the Klair de Klune:
This is the first time I’ve published a BOM. If you see any errors, please email me at email@example.com.
The BOM is a CSV file. I’ve been able to view it in Excel, OpenOffice, NeoOffice, and Numbers.
PCB for the Klair de Klune:
The link above will take you to a project page on the OSH Park website where you can order Klair de Klune PCBs if you want to.
Building the Klair de Klune
I had some Gorva aluminum enclosures that have more or less the same width and length as a Hammond 1590BB, and a little more depth (photos #1 and #2). By the way, a 1590BB-sized enclosure should work just fine. I marked up one of them with my trusty red Sharpie, drilled it with my trusty Craftsman drill press (equipped with a trusty multibit), smoothed the drills with my trusty demurring tool, and got rid of the remaining marks off with “regular” and “extra strength” rubbing alcohol (photo #3).
I used the hardware shown in photo #4. Clockwise from left: oxblood knobs vaguely like the ones on the original unit, DC power jack, LED mount and 3mm red LED, footswitch, Switchcraft 1/4″ jacks. Photos #5 and #6 show the enclosure drilled with hardware in position.
When I completed the Klair de Klune PCB in EagleCAD, I submitted the .brd file to OSH Park and ordered 3 copies of the PCB (they do everything in threes, like the Ramans). Photos #1 and #2 show what they sent me, in all its resolute purple-ness. Photos #3 and #4 show the components I soldered to one of the boards.
Photo #5 shows something I usually do with diodes and transistors: I use heatsinks when I solder them. It’s not always absolutely necessary but I like to err on the side of caution. In this case, I used heatsinks on the leads of the two 1N34A Germanium diodes (see schematic). Photo #6 shows the 1N34A’s (center right at the corner).
I used potentiometers that connect straight to the board (photo #1), instead of pots with solder lugs. I usually use double-stick foam tape on larger pots in general, to prevent the metal housing from shorting any solder points on the underside of the PCB. Note: for this pedal, the pots are oriented “up”, in other words, toward the side of the pedal where the jacks are. Photos #2 and #3 show the PCB with the wiring done.
The photo above shows the Klair de Klune all wired up and ready to plug in. Note the footswitch (lower left): it’s 3PDT but one of the channels is unused. That’s because this pedal was built according to the bypass layout of the original Klon Centaur, which is not “true bypass” and is often referred to as “buffered” bypass. Take a look at the schematic, particularly C2, R3, and R4. That’s where the audio signal is routed when the effect is disengaged. C2 and R4 are in series with the signal, and R3 runs between the signal and ground. I thought about tweaking the Klair de Klune to do true bypass, but I decided to stick to the original. It certainly simplifies the wiring – I didn’t have to route wires between the audio jacks and the switch. Referring the photo above, the three white wires are for switching between the effect path and the “buffered” output, and the two blue wires are for the LED.
If you look at the layout, you’ll see a lonely little hole for the ground wire of the LED, marked LGS, way out at the lower right-hand side of the PCB. I ran the wire under the board all the way back to the switch. In the photo above, you can see it running out from under the board to the switch (middle lug). The other LED ground wire runs from the switch to the hole marked LG. The switch opens and shorts the current path through the LED.
One more thing: there is plenty of room for a battery but I haven’t put one in yet. I’ll put up an action-packed photo of it if/when I do.
Finally, I etched some lettering… because I could. The photo above shows my advanced etching skills. Yeah.
I was going to try to draw a little stick-figure horsie-guy on the enclosure but I decided that the nice people reading this post shouldn’t have to suffer like that.
I have one more thing to say at this point: I wasn’t terribly precise about measuring the positions of the drill holes. I just put the PCB on top of the enclosure, roughly centered in both the X and Y axis (see photo above). For Y (height), I figured that an equal amount of space on the ‘top’ and ‘bottom’ (looking down on it from above) would allow room for the switch and the audio jacks. For the position of the potentiometer drills, I measured the distance between the PCB pins of a post and the center of the shaft, and then marked the positions on the enclosure relative to the holes for the PCB pins. Then I estimated the position of the LED so it would sit roughly underneath the two-hole footprint on the PCB (see layout). I’ll try to put up a drilling layout sooner or later.
That’s it for now. I will add information and correct things here as needed. Thank you for reading.