ALM/Busy Circuits AXON-1 ()

Four extra CV inputs in 4 HP—no cables, no fuss, just more control where you need it.

Overview

The AXON-1 isn’t flashy, and it doesn’t make a sound of its own—because it’s not supposed to. It’s the quiet enabler, the utility player in the ALM/Busy Circuits lineup, built for owners who’ve hit the modulation ceiling on their SQUID SALMPLE, MFX, or Pamela’s PRO Workout and need more. Instead of juggling mults or sacrificing patch space, this tiny expander bolts directly onto compatible modules and delivers four additional freely assignable CV inputs. No external power, no extra cables—just plug it in, assign the inputs in firmware, and go. It’s the kind of module you don’t know you need until you’re knee-deep in a complex sequence and realize you’re out of modulation lanes. Then, suddenly, it’s indispensable.

Made in England by ALM/Busy Circuits, the AXON-1 carries the brand’s no-nonsense, engineer-first ethos. It doesn’t try to impress with lights or knobs; it solves a specific problem with surgical precision. At 4 HP and 38 mm deep, it’s skiff-friendly and conserves space—critical in a crowded Eurorack system. And because it draws power directly from the module it’s attached to (40 mA on +12V, nothing on -12V or 5V), there’s no need to fumble with extra power headers or worry about cable strain. It’s the kind of design that feels obvious in hindsight—why didn’t every expander work this way?

It’s worth noting that if you’re pairing it with the SQUID SALMPLE, you’ll need firmware 166 or later. This isn’t a limitation, just a checkpoint—ALM’s firmware updates often unlock new hardware integrations, and the AXON-1 is no exception. For owners of the MFX or Pamela’s PRO Workout, compatibility appears seamless, though the fact sheet doesn’t specify firmware dependencies for those pairings.

Specifications

Manufacturer	ALM/Busy Circuits
Model	AXON-1
Model Number	ALM022-EXP1
Dimensions	4 HP, 38 mm deep
Current Draw	40 mA +12V, 0 mA -12V, 0 mA 5V
Function	Provides 4 additional freely assignable CV inputs
Power	Powered directly from the module, no additional power header required
Firmware Requirement	Requires firmware 166 or later for use with Squid Salmple
Design Feature	Each modulation assignment includes digital attenuation and offset
Form Factor	Skiff friendly
Country of Origin	Made in England
Original Price	$140

Key Features

Four Freely Assignable CV Inputs

The entire reason the AXON-1 exists is right here: four extra CV inputs that can be mapped to any parameter you need. Whether you're modulating step length on the SQUID SALMPLE, tweaking clock divisors on Pamela’s PRO Workout, or adding motion to MFX’s modulation matrix, these inputs remove the bottleneck. And because they're freely assignable, you’re not locked into fixed modulation paths—flexibility is built in from the start.

Digital Attenuation and Offset per Assignment

This is where the AXON-1 moves beyond simple expansion. Each CV input isn’t just a pass-through; it includes digital control over attenuation and offset. That means you can scale incoming CV signals precisely and shift their baseline—no external attenuators or offset generators needed. It’s a small detail that saves panel space and streamlines complex patches, especially when dealing with sources that don’t match the expected voltage range.

Direct Module Power, No Extra Cables

One of the most underrated aspects of the AXON-1 is how cleanly it integrates. It draws all its power directly from the host module via the backplane—no flying bus cables, no risk of dislodging a power connector. This makes installation fast and reliable, and it’s a big win for skiff users or anyone who values a tidy build. The fact that it pulls zero current on the -12V and 5V rails means it won’t burden your power supply unnecessarily.

Compact and Skiff-Friendly Design

At just 4 HP wide and 38 mm deep, the AXON-1 is built for efficiency. It doesn’t dominate your rack; it tucks in quietly. Its low profile and minimal depth make it ideal for skiff cases or systems where every millimeter counts. ALM didn’t waste space on extras—there’s no display, no buttons beyond what’s necessary, no blinking lights. It’s pure function, housed in a utilitarian panel that matches the aesthetic of the modules it expands.

Collectibility & Value

The AXON-1 was originally priced at $140, and current market listings show prices ranging from $126.12 to $177.95. Some retailers, like Detroit Modular, list it at $139.00, suggesting it’s still available new from authorized dealers. There’s no evidence of significant price inflation or scarcity, which makes sense—this is a niche expander, not a headline-grabbing synth voice. Collectibility appears driven more by utility than rarity. Owners aren’t buying it as an investment; they’re buying it because their SQUID SALMPLE needs more modulation. There’s no data on common failures or maintenance issues, likely because the module has no moving parts and minimal circuitry. As long as the firmware is up to date and the connection to the host module is secure, it should run indefinitely.