AMSynths AM1028 Sequential Volts (2024–)

A modern Eurorack module that finally builds ARP's unrealized slave unit and gives one sequencer eight more lanes of voltage.

Overview

Say you're deep in a patch, the sequence is running, and you need one more column of control voltages. The AMSynths AM1028 Sequential Volts is the fix. ARP planned a slave module for the 1027 Clocked Sequential Control in 1970 and never built it. This 8HP Eurorack module expands the Behringer 1027 and finishes that plan more than half a century later.

The AM1028 is not a standalone sequencer. It's a satellite that mirrors the eight steps of the Behringer 1027 over a 12-way ribbon cable. The 1027 gives you step sequencing with gate and trigger outputs. The 1028 adds three CV outputs per step: one 0-2V output for VCO pitch control, and two 0-10V outputs for deeper modulation like filter cutoff sweeps, amplitude shaping, or envelope depth. So a monophonic sequence can change several things on each step, not just the note.

The 2V output is built to maximize resolution for pitch control. Small moves of the front-panel Alpha potentiometers give precise semitone or microtonal shifts, without the coarse jumps you sometimes get from full-range 10V outputs on oscillators. The 10V outs are strong enough to drive nearly any voltage-hungry module in your rack, from resonant filters to complex envelope generators. The front panel has eight flat-top LEDs that show the active step. The build is anodized aluminum, solid and plain.

Specifications

Key Features

Historical Fulfillment: The ARP Slave Module That Never Was

In 1970, ARP drafted plans for a slave module to accompany the 1027 sequencer in the 2500 system. It would have multiplied the sequencer's control voltage capabilities without requiring full manual patching. That module never made it past the drawing board. Fast-forward 54 years, and AMSynths has built it. The AM1028 is not a speculative reinterpretation. It's a realization of ARP's original intent, and it's aimed at ARP 2500 fans and Behringer 1027 users.

Modular Flexibility: Placement Without Patching Penalty

The ribbon cable connection gives the AM1028 some freedom in placement. You don't need a forest of patch cables, so you're not locked into mounting it next to your 1027. You can put it near the modules it controls, say beside your filter stack or VCO bank, which cuts cable clutter and voltage drop over long runs. If you need more than one, the daisy-chain capability lets a single ribbon cable feed multiple 1028s, especially with the optional AMSEQBUS PCB.

Precision Control and Build Quality

The panel uses Alpha potentiometers, known for a smooth, durable action, so voltage adjustments are tactile and repeatable. Rogan knobs match the classic ARP 2500 style. Their shape and grip make fine adjustments easy, even in dimly lit studios. The LEDs are color-matched (red for red knobs, etc.), a small detail many utilitarian modules skip.

Historical Context

The ARP 2500 was never built for mass production. It was a boutique, semi-modular system aimed at studios and experimental composers who needed a lot of control. Its 1027 Clocked Sequential Control was one of its most powerful modules, but ARP saw its limits. A slave unit was the logical next step: multiply the sequencer's influence without multiplying complexity. Then came the 2500's low production numbers and ARP's eventual pivot toward more accessible synths like the Odyssey, and the slave module faded away.

In 2023, Behringer released its 1027 clone as part of its Eurorack 2500-series replication project. Thousands of users suddenly had a historically accurate 1027, with the same limitation: only one column of CV control. AMSynths stepped in there. Rather than cloning another filter or oscillator, they targeted a gap in the ecosystem, a missing piece for a system that now had millions of potential players. The AM1028 answers the question "What if ARP had finished this?"

Collectibility & Value

At £99 (around $125 USD), the AM1028 is priced as an accessible expansion rather than a luxury add-on. It's not a standalone centerpiece, but for anyone invested in the Behringer 1027 or building an ARP 2500-style system, it's borderline essential. New units are in production as of 2024, so availability isn't an issue yet. Given its niche appeal, it's likely to become a sought-after companion piece for purists aiming for a complete system.

There are no known failure points specific to the AM1028. CMOS buffering and diode protection suggest AMSynths planned for signal integrity problems or reverse voltage in daisy-chained setups. The module ships with high-quality components throughout, and user reports indicate solid build consistency. It relies entirely on the Behringer 1027 for timing and step control, though. Any issue with the host module, like ribbon cable connection faults or timing jitter, will directly affect the 1028. Make sure your 1027 works properly before adding this expander.

If you're shopping used, inspect the ribbon cable for fraying or bent pins. AMSynths includes one, but replacements aren't always bundled. Verify that all eight LEDs light and that the pots turn smoothly without crackling. The module has no firmware or digital components, so there's no risk of bricking or update issues. It's purely analog control voltage distribution, so it should last essentially forever, assuming no physical damage.

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