Schlappi Engineering - 100 Grit

by Ellison Wolf

Schlappi Engineering 100 Grit

I’ve been a fan of circuit bending ever since I figured out that if you do it on a machine powered by batteries, and not plugged into a wall, you [mostly] don’t have to worry about bodily injury or breakage to the machine due to frying yourself or the components. Really, circuit bending is some of the most deviant behavior to be had with consumer electronics, as there’s always the hope that you’ll coax demonic noises out of some garage sale castoff that’s plastered with pictures of barnyard animals all over it, or that you’ll hit circuit bending pay dirt and hear someone trying to contact you from another dimension through a machine built by a team of Fisher Price electrical engineers. You just never know.


With this in mind, and due to the potential inherent dangers of AC-powered [i.e., NOT BATTERY POWERED] more adult-ish toys I totally enjoy the fact that Schlappi Engineering has a feature on their new 100 Grit that is a direct implementation of circuit bending, and that we don’t have to risk life, limb, and module to do it ourselves. Namely, I’m talking about the 8 brass knobs situated at the top of 100 Grit, which are resistive patch points connected between various parts of the circuit, and a hell of a lot of fun. Aside from looking interesting, having something different in a tactile sense—something out of the Eurorack norm—100 Grit is a beautiful, interesting looking/playing offering, and makes perfect evolutionary sense as the third release from designer Eric Schlappi.

Setting aside its most obvious feature for just a minute, at its [triangle] core, 100 Grit is a 24dB low pass ladder style filter with an OTA style VCA and a distortion circuit. The layout of 100 Grit is pretty easy to decipher: you’ve got two audio inputs [In 1, In 2], inputs for voltage control over frequency, resonance, and gain, a three position gain switch, separate outputs for the VCA and distortion, and various feedback paths. There’s also a jumper on the back of the module which will let you compensate for pushing the resonance higher by adding bass and volume. Having that on the front plate as a toggle switch might have been nice, but in my testing of the module I didn’t think too much about it.


I’ve seen Eric Schlappi perform a couple of times, and it’s obvious how much he thinks about the playability and live performance aspect of his modules. I mention this because one of my favorite features [aside from those brass touchers, of course!] is the three-way toggle switch. It has a center [off] position, a x100 distortion position to the left [which multiplies the distortion by 100], and a momentary switch on the right side that also increases the distortion by 100, but only for as long as you hold the switch in that position. In conjunction with the filter cutoff knob, which is directly to the left of the toggle, it means that you can change the distortion parameter and cutoff frequency with your right hand while your left is working the brass touch points, making for a really interactive experience. When this method is employed, pairing the touch points with a ladder filter circuit really starts to seem like a genius move.


100 Grit has a lot of tricks up its scratchy sleeve, and while there is little that is “normal” about this module, there is a lot of normalization happening under its faceplate [which is, by the way, available in black or silver]. Four of the six function knobs [sans the large frequency knob] have alternate functions labelled on the front and are activated merely by leaving its input unpatched. Basically, the less you patch, the more the normalization takes effect and more distortion [via the normalization] is added to the circuit. This brings about a sort of Catch-22 to the 100 Grit. Do I patch it all up and modulate the hell out of this thing? Or do I leave it unpatched and destroy some shit? It took me some serious soul searching to answer that question.

I really like the sound of the filter [though that’s not why you’re buying this], and the VCA is perfectly serviceable [again, not why you’re buying this], and the distortion spans a wide range and can bark with the best of them, but, eh...never mind, let’s talk about those brass touch points!


The touch points—these conduits into the inner workings of the module, and by relation, your entire rig—really connect you in a way that turning a knob, flipping a switch, hitting a plastic pad, or pushing a red-capped momentary button just can’t do. There’s so much thought and knowledge needed to really get the most out of synthesis and the tools involved, that sometimes it’s nice to just be able to touch something, create some sonic destruction, and let go for a minute or two and forget yourself. I had so much fun with these, that it wasn’t until I pulled myself away for a few minutes and had a look at the quickstart manual that I realized that while I was randomly messing with the brass knobs Schlappi has laid out and described exactly in what part of the circuit each of the eight touch points is connected to: Distortion, Filter frequency, Gain CV. . . there’s more control than what first meets the eye. 100 Grit, with its associated brass touch points, are the modular synth version of bashing a drum kit after a crap day on the job, and having it in my rig has been a very welcome and therapeutic solution to the internal combustion that can—and does—easily form during a long work week. This one’s a hit for sure.


14 HP +12V 55mA -12V 70mA

Price: $260


schlappiengineering.com