Parasit Studio

Parasit Studio is a one-man DIY pedal business: Fredrik Lyxzén designs the circuits himself, and the manuals are written in his own voice, describing each build goal directly, such as the 8-Bitar's aim "to achieve a square wave octave down with as few components as possible"⁵.

How the PCBs and kits work

Parasit Studio's products are mostly circuit boards, not finished pedals. You buy the PCB, source the components from the bill of materials in the build document, and wire it into an enclosure yourself with offboard parts such as a 3PDT footswitch, jacks and a bypass LED. Build documents list the BOM, PCB dimensions and enclosure recommendations; the 8-Bitar document, for example, gives a 28mm x 37.5mm board that fits a 1590B enclosure¹. Some designs also have stripboard (vero) layouts published as an alternative to the PCB, including the Sentient Machine and both versions of the Sidescroller⁸⁹.

Complete kits, with components included, come from third parties: Das Musikding sells kits for many designs¹⁰¹¹¹², and the U-235 kit is also stocked by Smallbear Electronics and Synthcube⁶. The Multiwave Mega PCB and its Musikding kit ship with a pre-programmed Attiny84 chip, so no chip programming is needed for that build¹³.

Octave fuzz and ring modulation

This is the heart of the catalog: CMOS-based fuzzes that square up the guitar signal and push it through logic chips.

The Corruptor turns the guitar signal into a square wave and modulates it against an internal oscillator; the ring modulated sound can be blended with square wave fuzz that is either straight or one octave up. The current 3.0 PCB adds a blend pot, an octave switch and a CV input for modulating the carrier frequency, none of which the 1.0 version had¹⁰. The Xor'cist covers similar ground plus a stutter function: its mix knob selects stuttering fuzz, stuttering ringmod, or alternating between the two, and the 2.0 stutter switch can be configured latching or momentary with a DIP switch on the PCB¹⁴. Its VOLUME pot is A100K¹⁷.

The Eagle Claw is a one-knob, one-chip design built around the CD4069, using a full wave rectifier for a strong octave up. Its single control is a B1M volume pot, with 1N5817 and 1N4148 diodes handling the clipping¹⁵¹⁸. The Sidescroller began as a personal challenge to build something similar to the Arcadiator in a smaller format using only CD4069 inverter chips; the MK2 dropped that constraint and was redesigned from scratch⁸. The Salad Days ring modulator modulates both the amplitude and the phase of the signal through two signal paths for a more pronounced effect, with FM mode for normal ring modulation and AM mode for a choppy tremolo; Parasit Studio describes its timbre as very bell-like¹⁶¹⁹.

Octave down

Two designs cover clean and glitchy octave down. The U-235 Suboctave Generator is an analog, monophonic octave down pedal built around a CD4046 phase locked loop chip for octave dividing. The clean signal comes through at all times, there is a Detuned Mode sitting between one and two octaves down, and a CV input can control the octave setting. Its BOM includes TL072, TL074 and CD4046BE chips, a C100K LEVEL pot, and 1M SENS and 20K DETUNE trimmers²⁰⁶.

The 8-Bitar goes the other way: a minimalistic octave down pedal whose design goal was a square wave octave down with as few components as possible, using one CD4069 chip and one transistor. It has a glitchy, gated sound reminiscent of the 8-bit era of videogaming, a single LEVEL knob, and Parasit Studio calls it a perfect build for a beginner or fans of small simple circuits. The 1.0 PCB is red and the 2.0 PCB is white⁵¹.

Guitar synths

Parasit Studio's synth designs range from analog PLL circuits to microcontroller-based digital pedals.

• Multiwave Guitar Synth: a guitar controlled oscillator with saw, triangle and square waveshapes, a 3-way octave control and a special ringmod setting. A PLL multiplies the input frequency by 128, then a switched capacitor creates the stepped triangle and sawtooth outputs. It was the designer's first pedal with waveshapes other than square waves²¹.
• 1985 Guitar Synth: the first digital guitar synth from Parasit Studio, based on two self-programmed Attiny85 microcontrollers. Its octave up oscillator uses a frequency counter that Parasit Studio says sounds "super glitchy, like a malfunctioning R2-D2." Both chips must run at 8MHz instead of the default 1MHz, set by running the bootloader¹¹.
• Liberation Frequency Fuzz: a CMOS-based fuzz with a square wave oscillator blended in with the fuzz. The oscillator tracks the guitar signal while staying freely tunable to any harmonic, from about one octave down to one octave up. It is the barebones version of the Ladder to the Moon guitar synth, which adds other features but lacks the warp feature and raw fuzz¹².
• Into the Unknown: a phase locked loop based guitar synth with fuzz, octave down and octave up, flanger-ish modulation, a resonant lowpass filter, and track and warp knobs for sound shaping²².
• Phase Locked Fuzz: built around a "discrete" phase locked loop using transistors and op amps instead of a dedicated CD4046 PLL IC, with a sawtooth oscillator in place of the typical square wave. It was designed as a personal challenge to learn more about phase locked loops²³.
• 0415 Guitar Synth: a square wave synth that can mix one or two octaves up against one or two octaves down, with OctDown and OctUp toggles, a MIX knob and an optional CV input that lets an external LFO modulate the upper octave or trigger the synth without a guitar connected. Version 2.5 simplified the circuit while keeping the same functionality²⁴.

Filter

The Sentient Machine is a resonant lowpass filter modulated by an LFO. It has a couple of voice settings, a standard wah sound and a unique "jah" vowel sound. At slow LFO speeds Parasit Studio describes a spacey sweeping sound reminiscent of a phaser, and at minimum depth and medium speed something almost like a tremolo. The PCB is available in the shop, and a stripboard layout PDF exists but is unverified⁸.

Console 84: sold assembled, not as a kit

The Console 84 is a monophonic guitar synth and fuzz pedal inspired by the consoles and computers of the 8-bit era, and it is the one Parasit Studio product sold fully assembled rather than as a DIY project⁴. It carries the maker's own sound engine and an original design, with two oscillators (P1 and P2) that each have individual settings, five save slots for presets, and Lumberg jacks²⁵³. Development started in the second half of 2019 and went through repeated revisions using various microcontrollers, analog circuits and user interfaces; Lyxzén says the design took five years to complete²⁵⁴.

Support and where to buy kits

Bare PCBs for many designs are sold through the Parasit Studio shop, including the Corruptor, Eagle Claw Octave Fuzz, 8-Bitar, Multiwave Guitar Synth, Liberation Frequency Fuzz, Sentient Machine, Subspace Transmission, Thundering Mantis, Into the Unknown, Xor'cist and Salad Days^{1015852021129142223}. Complete DIY kits come from Das Musikding for the Corruptor, Eagle Claw Octave Fuzz, RC Box and Green Currant Tremolo^10151112. For any Musikding kit with a faulty, incorrect or missing component, Parasit Studio directs buyers to contact musikding directly, and Smallbear Electronics kit buyers to contact Smallbear Electronics²⁶.

For build trouble, the build documents point to the madbean forum's Parasit Studio subforum for troubleshooting help²⁷⁶, and general offboard wiring is covered by a PDF on the Parasit Studio website⁶. Contact is via parasitstudio@gmail.com²⁸.

Beyond the effects above, the range includes the Green Currant Tremolo, based on the TDA7052A amplifier chip with what the maker calls a very percussive attack and a slightly phasey, vibey sound²⁹; the Thundering Mantis, a CD4007 based pedal doing octave up and down aimed at weird glitchy lead sounds³⁰; the Bat Ear Fuzz, a one-knob CD4007 fuzz that starves one of the mosfets inside the chip for asymmetrical wavefolding, producing a mean octave up sound that cleans up with the guitar volume (the waveform looks like Batman's ears, hence the name)³¹; the Raygun Youth Chaos Fuzz, unchanged since its original release²⁹³⁰³¹; and the Subspace Transmission, aimed at playing along to riffs and pitching loops down for drone sounds²⁹³⁰³¹.

Questions