
Okay, here’s an old weirdo I’ve been meaning to write about for ages. The Systech Harmonic Energizer is an ultra-rare filter/distortion effect from the ’70s that takes the fuzz-wah formula in some interesting directions. Its signature is edgy, ultra-resonant filter sounds. You’re most likely to have heard it generating Frank Zappa’s nasal midrange squawk, but it does lots of other abrasive tricks too. I used this one on Tom Waits’s “All Stripped Down,” and on “Jets” by Action Plus.
The S.H.E. doesn’t do pretty. Most of its sounds are so strongly flavored, they’re hard to use as a primary tones. But it’s great for things like clanky percussive accents, or walloping low-frequency assaults.
But let’s talk later. First the video:
This is one of the few pedals accorded “Hen’s Tooth” status in Analog Man’s Guide to Vintage Effects, a cool reference book that seems to be getting as hard to find as — well, Systech Harmonic Energizers. Author Tom “Analog Man” Hughes tracked down Greg Hochman, who was the president of Systech back in the ’70s. Hochman said:
We did a custom preamp for a guitar that Greg Lake had. We were in Kalamazoo, where Gibson was….Ritchie Walborn had designed it; others asked us to build one for them. It eventually became what we called the Harmonic Energizer. It was a variable-state filter, which was kind of high-tech at the time, and it got a pretty good following from Joe Walsh to Jan Hammer….It allowed you to dial in up the Q of the filter, and by changing the frequency of the filter, you actually had the ability to choose what key you were going to have sustain and feed back. The thing actually had 55dB of gain when you got it up to a high-Q filter, so it didn’t allow you to be subtle onstage. It was dangerous, but it had a unique sound to it.
“Q” is another word for bandwidth, and the ability to dial in narrow bandwidths at high gain is what makes the S.H.E. so “dangerous” and interesting. But I have to admit I’ve never gotten close to choosing feedback frequencies by key as Hochman describes. That makes it sound like a refined musical instrument. But it’s really a nasty and unpredictable squawk machine. (Not that that’s a bad thing.)
A couple of years ago we dissected my S.H.E. over at freestompboxes.org, my fave stompbox group, which generated this long and interesting thread. (You might have to register to read it, but you should anyway — F.S.O. is a great little community.) I wound up with a clone that sounds a little better than the original, though it would probably be an even match if I weren’t too lazy to clean out all dirty pots and loose jack on the original.

The S.H.E. has a deceiptively simple set of three controls: gain, filter cutoff frequency, and filter bandwidth. At moderate settings, it yields an assortment of stationary wah sounds. But you can also dial in ultra-narrow, ultra-resonant filtering beyond the range of most wahs. And these edgy filters burst into overdrive in weird, unpredictable ways. User beware.
It’s easy to build or buy a clone. Madbean, one of the participants in that original freestompoxes thread, sells a clone PCB called the Karate Shop, with a project PDF here. (I love the fact that Madbean includes schematics and parts lists for all his project — the info’s there even if you don’t purchase any of his PCBS.) A completed Karate Shop will sound pretty much the same as the pedal in my video. Several other boutique builders offer pre-built clones, including Godlyke’s Triskelion, which Dweezil Zappa endorses. (The website says it’s out of production, but that they’re doing a 2013 update.
But I’m less interested in clones than improving/updating the circuit. I’d like to tweak the filter response, and I’d like to try it with a more inspiring distortion stage, maybe something germanium-based. Though I’m not sure whether it would be cooler to offer more filter options (filter types other than low-pass, for example), or adhere to the minimalist three-knob format.
Hmm — could it be time for a group collaboration?
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