“These two photos show my testing jig for Centaur boards, with one of my experimental boards on it,” Bill Finnegan shares. “The experimental boards have sockets for every component in the circuit, which enables me to listen to any particular component and then swap it out for a substitute while keep everything else the same. This experimental board is the one I used for developing the KTR. Unlike the Centaur which had through-hole components with leads, I wanted to use surface-mount components for the KTR, which meant that my assistant, John Perotti, and I had to spend an enormous amount of time soldering through-hole leads onto hundreds of very small surface-mount components so that we could evaluate them and choose the ones that would make the KTR sound the same as the Centaur did.” Photo by Nolan Yee.

“I was going to have to kill it before it could kill me,” Finnegan recalls. In 2008, he began working on a ground-up redesign that had to meet the following criteria: It had to be straightforward to build, so that any good contract manufacturing firm would be able to do the job easily and well. It had to be rugged and reliable. It had to be a design with no hookup wires whatsoever, and with a modular footswitch assembly so that faulty footswitches could be replaced in a few minutes. It had to be considerably smaller than the Centaur. Except for the all-important clipping diodes, it had to have surface-mount components, which take up less space on a board than traditional through-hole components. Finnegan also wanted to prove—to himself and to those who said it couldn’t be done—that, with careful component selection and smart board layout, he could design a successor that would sound exactly the same as the Centaur.

“This turned out to be quite a challenge,” Finnegan says. “My assistant, John Perotti, and I spent almost two years listening to different surface-mount capacitors in various places in the circuit before I felt this had been achieved.” Lastly, he wanted the new unit to be visually unique—a tall order, given that the unit would be housed in a standard enclosure.

I don’t have any overall preference for single-coil guitars or humbucker guitars myself. I like pretty much everything under the sun in the way of electric guitars, and over the years I’ve owned a bunch of very different ones.

The one new feature Finnegan wanted to incorporate was a switch that enabled the player to choose the buffered output of the original Centaur or a true-bypass output. “Without the buffer there is a very noticeable degradation of the signal due to the capacitance inherent in guitar cables,” says Finnegan, “but some people prefer it, so I wanted to provide that option in the new unit.” He quickly adds, “My good friend Paul Cochrane—of Tim and Timmy [pedals] fame—was the guy who designed the switching circuitry, so a tip of the hat to Paul.”

It took a long, long time to finish the KTR. And though Finnegan says it was much more difficult than he expected, he feels it has achieved all of his design objectives. “It sounds the same as the Centaur, takes up considerably less space on a pedalboard, is less expensive, and it’s distinctive aesthetically—it’s got the Klon thing going on.” He laughs, “Whatever the Klon thing is.”

You obviously have high expectations from your designs, though you’re also perplexed by the reactions it inspires. What do you want people to see in Klon?
What I want people to expect from me and from Klon are designs that are exceptional in the literal sense of the term—designs that are conceptually sound and well executed. Designs that are unique and not to be expected from any other designer, no matter how talented.

When you were designing the Centaur, did you begin with any assumptions about players who’d be interested in it?
I was working from the assumption that there were a lot of guitar players with really good guitars and really good amps who were looking for an overdrive pedal that—whether it was adding dirt or not itself—wouldn’t mess up what they already had and liked. Given the popularity of the Centaur and now the KTR, I would say that this has been borne out.

Top 5 Klon Myths

Gear forums are regularly aglow with all sorts of comments about Klon. Here are the most common misconceptions.

Myth No.1: The Centaur is a slightly tweaked [insert name of extant pedal here] circuit. According to Klon’s Bill Finnegan, “it’s a much more complex circuit than the typical overdrive/boost circuit. These claims stopped almost immediately after it was reverse-engineered in 2007 and a schematic was posted online.”

Myth No.2: Certain Centaurs sound better than others. Finnegan says he’s heard this claim about earlier units, later ones, gold ones, and silver ones. “The fact is, under the hood they’re all basically the same. In 1995 I made three small changes: I added a resistor to give the circuit some protection against a static charge delivered to its input—a change that has no sonic effect. I also had the circuit board redesigned with a ground plane for better grounding—again, no sonic effect except the potential for a little less hum. And I added a resistor to give the circuit a very small amount of additional low-mid response—I wanted it to have a little more roundness when used with, say, a Strat into a Super Reverb. I made no other changes.”

Myth No.3: The KTR doesn’t/can’t sound as good as the Centaur. Finnegan says this claim arises because the KTR uses surface-mount parts while the Centaur (and most other pedals) use through-hole parts. “For two years my assistant, John Perotti, and I listened to hundreds of different surface-mount parts throughout the circuit,” Finnegan explains. “While it wasn’t an easy or pleasant process, we both feel—and now a lot of other people feel, as well—that I achieved my design goal: With careful component selection, the KTR sounds the same as the Centaur.”

Myth No.4: You have to play really loud for the Centaur or KTR to sound good. “You need to have the output knob high enough that the signal hits the front end of your amp harder than your bypassed signal would,” says Finnegan. “In other words, you need to use the unit as an overdrive in the literal sense of the term.” The assumption here is that users are pairing the Centaur or KTR with an all-tube amp. “It’s always a good thing if your amp is turned up enough to get the harmonic response and distortion that are engendered by tubes clipping and output transformers saturating. This is true whether you’re playing through a 4-watt or a 100-watt amp.”

Myth No.5: Certain clones sound “exactly the same” as a Klon. Finnegan’s contention is that, given several factors—especially the rarity of the Centaur’s germanium clipping diodes—it would be extremely difficult to create an identical-sounding overdrive/boost.

In your opinion, do the pedals work better with single-coils or humbuckers?
Neither. I don’t have any overall preference for single-coil guitars or humbucker guitars myself. I like pretty much everything under the sun in the way of electric guitars, and over the years I’ve owned a bunch of very different ones. Each of them has its own particular thing going on, and when I was working on the design of the circuit I was always thinking about how it could be more effective in preserving and accentuating the essence of whatever instrument it was receiving the signal of.

What can you tell us about Centaur units that occasionally turn up on eBay with the claim that they are “new, with full warranty”—are they fakes?
I have a very close friend who is a single mom and whose job doesn’t pay all that well. Every now and then she needs a little help, financially. I’m aware of what the used units are selling for, so at some point after I discontinued the Centaur it occurred to me that—if and when she needed me to—I could build a Centaur and give it to her to sell on eBay and use the proceeds to keep going. This has worked really nicely, and I’ll continue to do it for as long as my old Centaur parts last. Since I discontinued the Centaur, a lot of people have asked me whether I’d consider building one for them—sometimes offering me pretty substantial amounts of money—but I’m not going to do that. The only Centaurs I build anymore are the ones I build for her, and I don't make or collect a single cent from them.