ALM S.B.G (2017–)
A Eurorack gateway to your pedalboard. Small footprint, a lot of signal handling, and a CV safety net most people forget they need.
Overview
Plug a guitar pedal into a modular rig without frying it, and you've already dodged half the battle. The ALM S.B.G has no flashing lights and no algorithmic effects. It makes sure your vintage analog delay doesn't get vaporized by a rogue CV spike. At 4 HP, it's barely wider than a patch cable, yet it handles level matching, wet/dry blending, and CV conditioning, the jobs that turn a chaotic pedal loop into something musical. You don't buy the S.B.G because it sounds magical. You buy it because you're tired of guessing whether your modular's 10V output will murder your Electro-Harmonix. Install it and forget it, until you realize you haven't had a single clipping incident in six months.
Designed and made in the UK by ALM's Busy Circuits, the S.B.G showed up when more and more users were bridging modular systems with external gear. Pedals offered textures no VST or module could replicate - spring reverbs, gritty overdrives, lo-fi bit crushers - and yet integrating them was a mess of impedance mismatches, level guesswork, and CV incompatibility. The S.B.G attenuates outgoing modular signals down to instrument level for safe pedal input, then amplifies the return signal back up to modular levels, with up to 34 dB of gain. A manual crossfade knob blends dry and wet signals on the fly, so live tweaking doesn't need a patched-in mixer. The real sleeper feature is the regulated CV output for expression control. Most pedal expression inputs expect a 0-5V sweep across a specific resistance, and feeding them raw modular CV can cause erratic behavior or damage. The S.B.G conditions that signal and includes a "floating ring" TRS cable to isolate ground loops.
It's not perfect. The S.B.G supports only a single signal chain, so stereo processing means doubling up or stepping up to the larger S.B.G-PRO. The front panel is sparse - just the crossfade knob and a red LED for clipping on the return path - so you're flying blind on send level unless you meter it externally. It handles instrument-level inputs fine, but it's not a mic preamp or line-level shifter, so don't bring a condenser mic to it. Owners report using it daily, because it's reliable.
Specifications
| Manufacturer | ALM (Busy Circuits) |
| Production Years | 2017– |
| Original Price | £100 GBP |
| Width | 4 HP |
| Depth | 32 mm |
| Power Supply | ±12V |
| Current Draw | +12V: 30mA, -12V: 30mA |
| Signal Path | Mono send/return |
| Send Attenuation | Modular to instrument level |
| Return Gain | Approx. 3 dB to 34 dB |
| Wet/Dry Control | Manual crossfade knob |
| Clipping Indication | Red LED on return path |
| CV Output | Regulated expression output with floating ring support |
| Connectors | 3.5mm jacks (audio), 3.5mm TRS (CV) |
| Accessories | Floating ring cable included |
| Construction | PCB-mounted jacks, aluminum front panel |
| Country of Origin | United Kingdom |
| Model Number | ALM006 |
Key Features
Signal Level Translation That Just Works
The S.B.G's core job is matching levels between Eurorack and pedals. Eurorack audio peaks around 10V, while guitar pedals expect instrument-level signals closer to 1V. Without attenuation, that mismatch causes distortion at best, oscillator locking or circuit stress at worst. The send path knocks the signal down cleanly, preserving dynamics without coloration. On the return, it amplifies the pedal's output back to modular levels, with a gain range that covers everything from whisper-quiet fuzz returns to line-hot stereo processors. The clipping LED only monitors the return path, so if it lights up, the incoming signal is too hot and needs more attenuation at the pedal or earlier in the chain. There's no auto-gain or feedback loop. The amplification is plain and predictable.
Wet/Dry Blending Without a Mixer
Most pedal integration setups require at least two VCAs and a mixer to blend dry and wet signals. The S.B.G puts that into a single knob. The crossfade is "equal power" in design, meaning the perceived volume stays consistent as you sweep from fully dry to fully wet, with no sudden dips or swells. It's manual only, so there's no CV control over mix (that's the S.B.G-PRO's domain), but for live use that's often a feature. There's no lag, no quantization, no menu diving - just a smooth, continuous taper that responds instantly to your hand. For pedals used as time-based effects (delays, reverbs), it feels like a built-in blend control on a vintage rack reverb.
CV Safety for Expression Control
The S.B.G protects both your pedals and your sanity. Expression inputs on pedals aren't designed for modular CV. A raw 0-10V LFO might make a pedal's sweep erratic, or worse, overload its internal circuitry. The S.B.G regulates the CV output to a safe, pedal-friendly range and includes a floating ring TRS cable that breaks ground loops, which are common culprits of hum when interconnecting gear. Service technicians observe that pedals with fried expression jacks often trace back to unregulated modular CV sources. The S.B.G acts as a buffer, so the control voltage behaves predictably and safely. It won't let you modulate the mix knob (again, that's the PRO model), but it will keep your $300 reverb pedal from becoming a paperweight.
Historical Context
The S.B.G arrived in 2017, just as Eurorack was shifting from boutique curiosity to mainstream staple. Modular users were no longer just synth purists. They were guitarists, field recordists, and hybrid producers looking to add analog grit to digital workflows. Pedals, with their decades of refinement and unique sonic character, were an obvious target for integration. But the tools to do it cleanly were scattered: DIY builds, mismatched attenuators, and risky trial-and-error patching. While other companies focused on flashy sound generators, ALM doubled down on utility modules that solved real-world problems with minimal fuss. The S.B.G wasn't the first pedal interface, but it was the first to package level matching, blending, and CV safety into a skiff-friendly 4 HP module at a sub-£100 price. Competitors like the ADDAC200PI offered dual channels but lacked CV conditioning, and others required external power or bulky breakout boxes. ALM later expanded the concept into the S.B.G-PRO, a 10 HP unit with balanced I/O and CV-controllable mix.
Collectibility & Value
The S.B.G isn't a collector's item in the traditional sense. There are no rare runs, no "first edition" quirks, and no aftermarket markup. New units still sell for around £100 GBP from authorized dealers, and used examples regularly appear on Reverb and eBay between £60 and £85, depending on condition. It has no moving parts beyond the potentiometer and LEDs, so failure rates are low. The most common issue reported is a loose input jack, usually from repeated plugging and unplugging of 3.5mm cables, a known weak point in PCB-mounted jacks under mechanical stress. Some users reinforce the connection with strain relief or avoid wiggling cables during live sets. The floating ring cable, while included, is occasionally lost or damaged. Replacements (ALM-UT003) are available for £8, but third-party TRS cables can work if properly wired. When buying, check the clipping LED: power up the module and verify it responds to a hot return signal. Also inspect the crossfade knob for scratchiness. Pot issues are rare, but the pot is the most likely wear point. Test it with a known pedal loop before relying on it in performance.
Market Value
┌──────────────────────────────────────────────────────────────────────────┐ │ ALM S.B.G Apr 2026 │ ├──────────────────────────────────────────────────────────────────────────┤ │ High $212 Latest $98 │ │ Median $120 Trend ▼ Down │ │ Low $98 Volume ~2/mo │ ├──────────────────────────────────────────────────────────────────────────┤ │ $300 ┤ │ │ │ │ │ │ │ │ $193 ┤. │ │ │ │ │ │ │ │ │ . .│ │ $50 ┤ │ │ ├─────────────────────────────────────────────────────────────────│ │ vol │█ █ █│ │ └─────────────────────────────────────────────────────────────────│ │ 2026-01 2026-02 2026-03│ └──────────────────────────────────────────────────────────────────────────┘
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