4ms Stereo Triggered Sampler (2018–)

A dual-channel stereo sampler that plays, records, and mangles sound with surgical precision and modular immediacy.

Overview

Plug in a microSD card, hit play, and two stereo samples burst from the outputs—clean, crisp, and perfectly timed. The 4ms Stereo Triggered Sampler (STS) doesn’t whisper its capabilities; it announces them the moment you patch it in. This isn’t a lo-fi nostalgia box or a granular sound blender—it’s a high-resolution, low-latency workhorse built for slicing, dicing, and reassembling audio with the kind of control that makes other samplers feel like toys. You can load up to 600 stereo samples at once, organized into 60 color-coded banks, and trigger them independently or together, forward or backward, at any pitch from -10 to +4 octaves. It’s like having two high-fidelity samplers in one 20HP module, each with full CV control over pitch, start position, length, and sample selection.

What sets the STS apart isn’t just its capacity or clarity—it’s how it lives in a modular system. Unlike many samplers that feel like guests in a Eurorack setup, the STS acts like a native citizen. Every parameter is CV-addressable: want to sweep the start point of a vocal snippet with an LFO? Done. Need to trigger a reverse cymbal swell via MIDI clock? Easy. The Play, Reverse, and Record functions all have trigger inputs, so you can sequence entire sample manipulations from a sequencer or drum trigger. And because it uses a microSD card that’s hot-swappable (no power-down needed), you can swap entire sound libraries mid-performance—say, from orchestral stabs to field recordings—without breaking stride.

The sound quality is clinical in the best way: 96kHz/32-bit WAV support means your samples retain their full dynamic range, and the module’s internal processing preserves detail even when you’re pitch-shifting or looping aggressively. But don’t mistake precision for sterility—the STS excels at creating organic textures. By adjusting the start and length parameters in real time, you can turn a six-second ambient pad into a stuttering glitch sequence or a granular cloud. Set the length to 8ms, and suddenly you’re doing basic granular scrubbing, slicing audio into tiny fragments that can be pitch-shifted and retriggered like a wavetable oscillator. Load a bank of single-cycle waveforms, and the STS becomes a rudimentary wavetable synth, playable via 1V/oct.

Specifications

Manufacturer	4ms Company
Production Years	2018–
Original Price	$450
Module Size	20HP
Power Consumption	+12V: 145mA, -12V: 41mA, +5V: 0mA
Audio Input Bandwidth	20Hz – 10kHz (+/-0.1dB), -6dB @ 20kHz
Audio Output Bandwidth	0Hz – 22kHz (-1.8dB max deviation)
Maximum Input Level	21V peak-to-peak
Maximum Output Level	+10.5V to -10.5V
Trigger Input Latency	0.7µs typical
Sample Playback Latency	0.7ms (after bank load)
Supported Sample Formats	WAV (up to 96kHz/32-bit/stereo)
Maximum Sample File Size	4GB
Maximum Samples per Bank	10
Maximum Banks	60
Total Maximum Samples	600
Recording Format	48kHz/24-bit stereo WAV
MicroSD Card Support	Hot-swappable, UHS Speed Class 3 recommended
Sample Editing	Non-destructive (start, length, gain, loop points stored separately)
Cue Point Support	Up to 4 per sample (via compatible software like Reaper)

Key Features

Dual Independent Stereo Channels

The STS isn’t just a stereo sampler—it’s two full stereo samplers in one module, each with its own sample selection, pitch, start position, and length controls. You can play two completely different samples simultaneously, pan them independently, or sum them for a unified stereo output. This dual-channel architecture makes it ideal for complex layering: imagine triggering a kick from one channel and a reversed synth tail from the other, all synced to the same clock. Each channel has its own Play, Reverse, and Record triggers, so you can sequence intricate sample interactions without external logic modules.

Non-Destructive Sample Editing

Every edit you make—start point, length, loop, gain—is stored in a separate control file, not baked into the original WAV. This means you can experiment freely: reverse a sample, trim it to 50ms, pitch it up two octaves, and then hit a button to return to the pristine original. The edits are saved only when you explicitly commit them (and must be saved before power-off), which protects against accidental overwrites. This non-destructive workflow is a godsend for live performance, where you might want to jump between different edit states of the same sample without reloading.

Real-Time Recording and Resampling

The STS isn’t just for playback—it’s a full recording module. You can record directly into a bank via the audio inputs, creating new samples on the fly. This turns the STS into a powerful resampling engine: patch the output of a filter or reverb back into the input, trigger a recording, and capture the processed sound as a new sample. Musicians using contact mics on drums or prepared pianos love this feature, as it lets them capture transient-rich material and immediately retrigger it in new rhythmic or melodic contexts. The recording format is 48kHz/24-bit stereo WAV, ensuring high fidelity even after multiple generations of resampling.

Historical Context

When the STS launched in 2018, the Eurorack sampler landscape was crowded but oddly limited. Most modules either focused on granular manipulation (like the Make Noise Morphagene) or lo-fi playback (like the Critter & Guitari Organelle). The STS carved out a new niche: a high-resolution, performance-oriented sampler built for integration, not isolation. It arrived alongside a wave of interest in live sampling and modular-as-instrument, where musicians wanted to trigger real-world sounds—vocals, field recordings, acoustic instruments—with the same immediacy as a drum machine.

4ms had already built a reputation for robust, deeply integrated modules like the Dual Looping Delay (DLD), and the STS continued that philosophy. It wasn’t trying to be a standalone workstation; it was designed to be part of a larger ecosystem. Its direct competitors weren’t other Eurorack samplers so much as external hardware like the Elektron Digitakt or the Akai MPC Live—but the STS offered something those couldn’t: seamless CV control and true modular timing. While the DLD focused on infinite looping and delay textures, the STS was about precision, repeatability, and multi-timbral performance. It filled the gap for players who wanted to trigger complex, high-fidelity samples without leaving the rack.

Collectibility & Value

The STS isn’t a rare bird, but it’s not cheap or common either. New units still sell for around $450, and used prices hover between $350 and $420 depending on condition. Because it’s a relatively modern module (post-2018), most units on the used market are in good working order, but there are a few things to watch for. The microSD card slot is robust but can wear out with frequent swapping—check that cards seat firmly and that the module recognizes them consistently. Some early firmware versions had bugs with cue point snapping, so verify the unit is running firmware v1.0.1 or later. The module ships with a 16GB card loaded with samples from artists like Richard Devine and Moor Mother, but replacements are easy to find.

Maintenance is minimal. There are no moving parts, and the circuitry is solid-state with no known failure-prone components. However, the non-volatile memory that caches banks (for fast 0.7ms access) relies on a small onboard battery. If a unit hasn’t been powered in years, that battery may be dead, requiring a service reset. This isn’t a user-serviceable fix, so if you’re buying NOS (new old stock), ask the seller if the battery has been checked. Otherwise, the STS is about as reliable as modular gear gets—no recalls, no widespread issues, just a well-built tool that does exactly what it promises.