Centaur

Finnegan had engineer friends, including an MIT graduate named Fred Fenning. Together they built prototypes in their spare time, and kept at it for more than four and a half years. That is a long time to spend on three knobs.

Fenning didn’t get to see what it became. He died in a plane crash in the mid-1990s, and Finnegan later gave him much of the credit for the design.

Late in 1994 Finnegan started selling the result. He called it the Centaur. It came in a cast enclosure in bronze, with oxblood lettering and a sword-waving centaur on the front that everybody calls “the horsie.”

Three knobs: Gain, Treble, Output. The interesting part is inside.

First, the Centaur doubles its 9-volt supply to 18 volts, which gives the signal more headroom. Then it splits your guitar three ways. One path goes to the distortion: a TL072 op-amp and a pair of new-old-stock 1N34A germanium diodes. A second path takes the clean low end straight to the output. A third path is clean too, and it fades away as you turn up the Gain.

That’s the trick. At low settings, most of what you hear is still you. As you turn it up, the dirt takes over gradually, and the bass never gets carved out. Most of the grit comes from the op-amp; the germanium only shows itself at the very top of the Gain.

The result is what people came to call a “transparent” overdrive: more gain, not much change in tone. Some ears hear a midrange push and a bit of added thickness in it too. Finnegan meant it to push an amp that was already breaking up, not to be the only dirt on the board. Used his way, you notice the amp, not the pedal.

He also poured epoxy over the circuit board. A circuit like this can’t be patented under U.S. law, so he made it hard to copy instead.

For the whole original run, Finnegan built, tested, and shipped every Centaur himself, from home. Every part was custom: the enclosure, the knobs, the pots. Orders took twelve to fourteen weeks to fill.

It never grew into a factory. The margins were thin and commercial space in Boston was hard to justify, so it stayed one man, at home. In 2008 he stopped, after about 8,000 pedals in fifteen years. Finnegan put it bluntly:

“I was going to have to kill it before it could kill me.”

Along the way it found a strange, wide crowd. Jeff Beck, Joe Perry, Matt Schofield, Ed O’Brien. Nels Cline named it among his usual pedals on Wilco’s 2011 album The Whole Love, with his ’59 Jazzmaster as his go-to guitar and a Deluxe Memory Man on the same board. Finnegan said it drew baby boomers, younger indie-rock players, and experimental musicians alike, which is about as broad as a guitar audience gets.

Finnegan didn’t walk away from the circuit. From 2008 he designed the Klon KTR, a version built for contract manufacturing and easy repair, and it came out in 2014. The one new feature is a switch for buffered or true bypass, designed by Paul Cochrane, who makes the Timmy. Printed on the enclosure is a note from Finnegan:

“Kindly remember: The ridiculous hype that offends so many is not of my making.”

The copies came anyway. The Wampler Tumnus, the Way Huge Conspiracy Theory, the Electro-Harmonix Soul Food, and plenty more. Put them through their paces and they get close, even with silicon diodes in place of germanium, which suggests the sound lives in the circuit’s design more than in any one part. By 2023 a DigiTech Bad Monkey was being shown to be hard to tell from a Centaur by ear. Finnegan, for his part, has argued that klones discourage people from engineering anything new.

He spent four and a half years making a box that would vanish under a player’s hands, and fifteen more building it one at a time. The one thing he never managed to make disappear was the noise around it.