Ljunggren Audio

Roll Your Own

Eurorack DIY




The RYO Penta is a compact 4hp 5 step sequencer for eurorack that's easy to build and low cost. It's great for simpler sequencer tasks such as basslines and arpeggios, transposing sequences, filter cutoff or anything where a repeating stepped modulation is wanted for adding movement to the sounds you're making.




The RYO Aperture is a vactrol lowpass filter and VCA module inspired by the much beloved 292 Lopass Gate from the Buchla 200 series modular system of the 1970s. However, rather than being a straight up clone, the Aperture is a newly developed and reworked design for eurorack modular synths.




A 4x4 cycling sequential switch, featuring simultaneous forward/reverse stepping, hold, reset, and an additional voltage controlled mode based on the same design as our VC Sequencer. Also on board are push buttons for each function enabling you to play and perform the switching with a more human input.



Airtenuator I


The RYO Airtenuator I is a floating passive attenuator you connect between two modules in your rack via patch cables, acting as a volume/modulation depth control between the source and destination.



Boolean Logic


The circuitries of the RYO logic gate modules are directly modeled after the very earliest form of digital logic gate designs using resistor-transistor-logic (RTL) pioneered in the 1950s and used in computing equipment throughout the 50s and 60s. The Apollo Guidance Computer for instance used the same type of 3-input NOR gate design now found in the RYO NOR/OR module, although in vastly greater numbers.





A compact, easy to use, easy to build and great sounding distortion module which will also work as a VCA if desired.



VC Sequencer


Compact 8-step sequential voltage source in 10hp with classic forward/backward operation using a clock, and any kind of pattern you like using control voltage levels scaled to each step of the sequencer, allowing the waveform you feed it with to determine the running pattern. All low latency CMOS and Opamp circuitry. No software or micro processors.



Trig Xpander (for VC Sequencer)


This will give your VC Sequencer 8 individual outputs for each step outputting either a trigger or a gate, selectable with a jumper on the pcb, and a 9th output that gives you a trigger for each step progression.





An easy to build precision 4-channel mixer/attenuator with 2.0x gain and 5V offset on each channel in an 8hp module.





A simple and space-efficient voltage controlled amplifier for processing of control voltages as well as audio with high precision and a good clean sound.





Download assembly manual here.


Out of production.





If you have any issues with your Kit or your Assembled RYO module, don't hesitate to drop us a line on info before @ followed by ljunggrenaudio.com and we will do our best to help you.



Regarding our PCB/panel only offerings, please note that these are mainly offered due to popular demand from the experienced DIY community. Hence we are counting on that you know what you are doing and how to source parts. If you feel the least bit uncertain, please consider going for the kit.