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Knight School Bit Crush DIY Kit
Knight School Bit Crush DIY Kit

Knight School Bit Crush DIY Kit





Long a studio trick of the trade, sample rate reduction (commonly called “bitcrushing” though the two are different) is a relatively new effect that takes snapshots of your input signal and “approximates” them with less and less accuracy as the effect intensifies. While virtually unknown to most just a decade ago, many modern synthesizers and outboard processing devices now come equipped with this effect. In a nutshell, it makes your guitar or other instrument sound like old-school video games. We’ve leveled up this effect by offering one simple addition: the humble Mix control. With this, you can use our Bitcrusher kit to destroy your signal as much or as little as you want with a simple twist. You can use the Bitcrusher as a processor for your other effects, blending in just a little for some amazing unique textures, or a ton for complete annihilation.

In the epoch of guitar effects, “bitcrushing” and “sample rate reduction” are among the newest. Despite its funky and rare usage, even ring modulators were available in the ‘60s. However, bitcrushing and sample rate reduction are distinct byproducts of digital technology, more specifically they pertain to quantization errors with respect to different axes. 

Be that as it may, the two terms have been conflated for years, but neither of these names appeared organically in the first iterations of these effects. The DigiTech Space Station called their sample rate reduction program “Pixelator”. Another early example—the Alesis Bitrman—calls theirs “Decimator”. 

Even though bitcrushing involves lowering the bit depth of the signal, it is the sample rate reducer that evokes the sounds most associated with ‘80s video games, and so that term became entangled with the concept of bitcrushing, such that many gearheads use the terms interchangeably and call it a day. It’s like in Texas, “Coke” at a restaurant can mean any type of soda. I disagree with both of these but the public has won out.

So, what does all this actually sound like? Well, sample rate reduction takes “snapshots” of the input signal at some high rate, and then drops the frequency at which these snapshots are taken into the audible range such that we can hear them. Each of these snapshots (Riemann sums for you math folks) becomes wider as sample rate is reduced, forming a “stepped approximation” of the input signal. The lower the sample frequency, the more “pixelated” with waveform looks, which is likely why DigiTech chose the program name in the Space Station. Either way, it reminds me of Atari games.

Our Bitcrusher kit is taken from the engine of one of our old-school pedals, the Heliotrope, which was itself an adaptation of an old DIY project, called (fittingly) “analog bit crusher.” If any effect begs for a mix control, it’s this. And surprisingly, many pedals that do this do not offer one. We do, and it makes for an absolutely killer effect. Run other pedals into it for some otherworldly flavor you just can’t find anywhere else.

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The circuit board has everything labeled as to what part goes where. You'll find the below image very helpful to identify what parts are what. There's also a video below showing you how the process will go.




DEGRADE:  This knob governs the sample rate. Fully down, the sample rate is not in the audio range, and so no effect is heard. Nudging the control up introduces some digital aliasing. Depending on where the knob is set, the “snapshots” are small enough to cause “note errors”, do not try to tune your guitar with this on. When maxed out, the signal is completely destroyed, like getting blown to bits in Asteroids. 

NOTE: The original setup for both the DIY schematic and our Heliotrope features a slight “whine noise” in the background. For this kit, many steps were taken to mitigate this noise and it is certainly lower in volume than the originals. Nevertheless, it is still there, albeit quiet.


MIX: Controls a full wet-dry blend between the input signal and the effect. When the knob is fully down, only the dry signal is heard. When it is fully up, only the effect is heard. Anything in between is an equal mix. Noon is 50/50. When you run other pedals before this device, say a fuzz for example, that becomes the dry signal in the wet-dry configuration, and so setting this knob to noon gives you half fuzz, half downsampled fuzz.


The Knight School Bit Crush accepts a center-negative DC power supply capable of supplying 9 volts. Plugging in anything other than this (center-positive, AC, higher voltage) will damage the pedal, maybe even beyond repair. Check your supply and make sure it says all the right stuff. Plugging in the wrong supply will void the warranty and possibly summon a puff of ozone-tinged smoke. Trust me, you’d hate it.