November 13, 2025
The Roland TR‑808 and TR‑909 drum machines hold a notable place in the history of electronic music. These instruments introduced new ways of creating rhythm, combining analog circuitry and programmable sequences. While originally released decades ago, their sound continues to be studied, sampled, and adapted into modern electronic music. At Jake’s Custom Shop, a series of Eurorack modules replicate the sonic characteristics of these machines, allowing musicians to explore 808- and 909-style drum sounds in a modular context. This article explores both the historical significance of the original machines and the details of these modules.
The Roland TR‑808 Rhythm Composer, released in 1980, was one of the first programmable drum machines that relied entirely on analog synthesis. Unlike earlier drum machines that used prerecorded samples or limited preset patterns, the TR‑808 allowed users to create sequences of any length, adjust individual drum sounds, and experiment with unique rhythmic structures. Its drum sounds, such as the low-frequency kick, the snappy snare, and the metallic hi-hats, have been widely sampled and used in various musical genres. While the original 808 was initially considered too synthetic for mainstream music, its affordability and flexibility allowed it to reach underground producers and emerging electronic musicians. Over time, these synthetic textures became iconic, influencing the sound of early hip-hop, electro, and dance music worldwide.
Following the TR‑808, Roland introduced the TR‑909 in 1983. The 909 combined analog synthesis for its drum voices with digital sample playback for cymbals, providing a hybrid approach that expanded the palette of sounds available to producers. It also offered a MIDI interface, allowing precise synchronization with other instruments, which was an innovation at the time. The TR‑909 was particularly valued for its tight, punchy kick drum and snappy snare, qualities that shaped the sound of early techno, house, and acid tracks. The combination of analog warmth and digital precision gave the 909 a distinctive character. Understanding these characteristics is essential when translating them into Eurorack modules, as the tonal balance, envelope shaping, and accent behavior define the recognizability of the original sound.
Jake’s Custom Shop has developed several Eurorack modules designed to replicate specific elements of the TR‑808 and TR‑909. The goal is not only to recreate the original drum sounds but also to provide modular users with CV control for shaping the sounds in real time. Modules allow for decay, pitch and accent via CV, making them flexible tools for adding dynamics to percussive melodies. These modules are designed with attention to the original circuitry while accommodating the constraints and standards of modern Eurorack systems. They provide a bridge between the classic analog designs of Roland and the flexibility of modular synthesis, giving users the ability to create intricate, customizable drum patterns with the recognizable tonal characteristics of the 808 and 909.
The JCS Snare Drum and HiHat Pro CV module replicates the sounds of the TR‑808. Using analog circuitry similar to the original machine, it offers CV inputs to control the decay of both drum voices. This allows musicians to adjust the tonal qualities and dynamics of the snares and hi-hats in a modular setup, producing a range of textures from tight, percussive hits to longer, more resonant tones. The module is suitable for integrating into complex sequences or layering with other drum voices. By providing precise control over the original 808-inspired sounds, it makes these classic textures accessible within a modern Eurorack workflow.
See JCS Snare Drum and HiHat Pro CV
Our Kick Drum Pro CV module is modeled after both the 808 and 909 kick drums. It incorporates dual voices, allowing users to select between the 808-style deep analog kick and the punchier 909 variant. CV inputs for decay, pitch, and accent enable dynamic shaping, while a sidechain envelope output can be used to modulate other modules within the system. An adjustable distortion switch adds the possibility of subtle or pronounced saturation, giving flexibility in the tonal character. The module’s compact 6HP size and low power consumption (+12V: 9 mA, −12V: 8 mA) make it easy to integrate into larger systems without compromising space or power availability. These features collectively make the module versatile for both rhythmic precision and experimental sound design.
The JCS Cowbell Advanced Pro CV Module reproduces the distinctive metallic tone of the TR‑808 cowbell. Users can manipulate the pitch and accent via CV, allowing for nuanced rhythmic articulation. The analog design ensures that the harmonic content remains close to the original, with the ability to adjust decay and accent to fit different musical contexts. The module can be used independently or layered with other percussive sounds for more complex textures. By integrating CV control, the module provides modular users with more precise performance options than the original fixed-parameter 808 cowbell, while still maintaining its recognizable tonal identity.
See JCS Cowbell Advanced Pro CV Module
This module emulates the TR‑808 handclap. The analog circuitry is designed to capture the transient characteristics of the original clap sound, including its percussive attack and decay envelope. Within a modular system, this module can be combined with other percussive voices or effects to create complex rhythms. Its design focuses on reproducing the 808 sound faithfully while allowing flexible manipulation in a Eurorack setup.
See JCS 808 Clapster Eurorack Module
These modules can be connected via CV to sequencers, envelopes, and other control sources in a Eurorack system. This allows for real-time modulation of parameters such as decay, pitch, and accent, enabling more expressive performances. By combining multiple modules, users can sequence patterns that emulate the classic 808 and 909 rhythms or explore new textures. The modular approach also allows experimentation with layering, routing, and signal processing that was not possible in the original drum machines.