ALM Stem Ripper Thru (2025–)

A tiny, passive gateway to cleaner patching—this unassuming expander quietly solves one of Eurorack’s most annoying cable tangles.

Overview

You know that moment when you're deep in a patch, trying to route your main outputs through a mixer while simultaneously sending them to a recorder, and suddenly you're wrestling with a nest of stacked cables that won’t stay put? The ALM Stem Ripper Thru doesn’t fix your whole rack—but it *does* fix that. It’s a 2HP passive module designed as an add-on to the ALM Stem Ripper, and its entire job is to duplicate the eight input signals to a second row of outputs, unbuffered and direct. No processing, no power, no fuss. Just clean signal pass-through so you can keep your patching flexible without relying on fragile cable stacks that inevitably wiggle loose at the worst possible time.

It’s not flashy, and it doesn’t expand the recording capabilities of the Stem Ripper itself—that’s still handled by the main module. But what it does, it does with elegant simplicity. The Thru module connects via a ribbon cable to the Stem Ripper, and then presents a second row of jacks that mirror the inputs. This means you can patch your sources into the Stem Ripper as normal, record your stems directly to SD card, and then use the Thru’s outputs to send those same signals elsewhere in your system—maybe to a mixer, a compressor, or a second recording chain—without overloading the input jacks or risking dropouts from poor contact in stacked cables.

Owners report that the build quality is consistent with ALM’s usual standards: clean silkscreen, sturdy jacks, and a compact 3U x 2HP footprint that won’t hog valuable space. But it’s worth noting—this is a passive expander, not an active one. There’s no buffering, no gain stage, no protection from impedance mismatches. That keeps it simple and reliable, but it also means you’re trusting the signal integrity to the passive pass-through design. In practice, this works fine in most setups, especially if you’re not driving long cable runs or splitting to multiple destinations beyond what the Thru provides.

Specifications

Key Features

Passive Signal Duplication Without Power Draw

The Thru module’s greatest strength is also its simplest: it requires no power. Because it’s a direct, unbuffered pass-through, it doesn’t consume any current from your power supply. That’s a small but meaningful win in a Eurorack system where every milliamp counts, especially on crowded power rails. It connects to the Stem Ripper via a short ribbon cable, which carries the eight input signals directly to the rear of the Thru module. There’s no active circuitry, no op-amps, no risk of introducing noise or coloration. What goes in comes out—just duplicated.

Eliminates Stacked Cables at Critical Points

Stacking patch cables is one of Eurorack’s necessary evils, but it’s also a common point of failure. Jacks can become unreliable, signals drop out, and the physical strain on the module can lead to long-term wear. The Thru module sidesteps this by giving you a dedicated second set of outputs. Instead of stacking a second cable onto the Stem Ripper’s input jacks, you patch into the Thru’s outputs. This keeps the original inputs free and stable, reduces mechanical stress, and makes your patch more reliable during live use or transport. For touring modular artists or anyone who gigs with their system, this small upgrade can prevent a lot of headaches.

Compact and Skiff-Friendly Design

At just 2HP wide and 32mm deep, the Thru module is about as space-efficient as it gets. It doesn’t require any additional power connectors or external cabling beyond the internal ribbon link to the Stem Ripper. This makes it ideal for skiff builds or compact cases where every millimeter matters. It mounts flush with the Stem Ripper, creating a clean, integrated look. The silver panel matches ALM’s standard aesthetic, so it blends in without drawing attention—exactly what you want from a utility module.

Historical Context

The ALM Stem Ripper Thru arrived in 2025 as a companion to the Stem Ripper, a compact 8-channel recorder that answered a growing demand for in-rack multitrack recording. While standalone recorders like the Zoom L-6 or field recorders with ADAT I/O could handle the job, they required external power, cabling, and often broke the immersive flow of a modular session. The Stem Ripper brought that functionality inside the case, and the Thru module completed the vision by addressing a practical limitation: how to access those recorded signals without compromising the patch.

At the time, competing solutions like the Half Time Modular 8TR offered higher bit depths and sample rates, but they didn’t include a dedicated thru solution out of the box. ALM’s approach was different—modular, incremental, and focused on workflow. The Thru module reflects a broader trend in Eurorack design: the rise of utility expanders that solve specific, niche problems rather than trying to be all-in-one solutions. It’s not a standalone product, and it’s not meant to be. It’s a surgical tool for a very specific workflow bottleneck.

Collectibility & Value

The ALM Stem Ripper Thru isn’t a collectible in the traditional sense—there are no limited editions, no alternate panels, and no aftermarket premium beyond its original MSRP. It sells for $80 new, and used units typically trade for $50–$65 depending on availability. Because it’s passive and has no active components, failure rates are extremely low. There’s almost nothing to break. The most common issue reported is ribbon cable disconnection, usually due to rough handling during module removal, but that’s easily fixed with a reseat or replacement cable.

When buying used, check that the ribbon cable is intact and that all eight output jacks are securely mounted. Since the module relies on direct signal pass-through, any cold solder joints or damaged traces would be immediately apparent as dead channels. However, such failures are rare. The bigger concern is compatibility—this module only works with the ALM Stem Ripper. It won’t function with any other recorder or interface, so don’t expect to repurpose it later. If you own the Stem Ripper and hate stacked cables, the Thru is worth every penny. If you don’t have the main module, it’s completely useless.

For restorers or builders working on vintage systems, the Thru module is a modern addition—nothing to restore, really, but also nothing to worry about. It’s built to last, and ALM continues to support the Stem Ripper ecosystem with firmware updates and spare parts. The included ribbon cable is proprietary but replaceable, and ALM’s documentation is thorough enough to guide repairs if needed.

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