AMSynths AM1028 Sequential Volts (2024–)

An 8HP Eurorack expander that breathes new life into the Behringer 1027 with three precision CV outputs and LED step tracking—like finding a missing puzzle piece for your 2500-style rig.

Overview

You know that itch when your sequencer can control pitch but leaves your filter and amp movements feeling static? That’s exactly where the AM1028 steps in—not with a flashy overhaul, but with surgical precision. It doesn’t reinvent the wheel; it just gives the wheel a second axle. Born from ARP’s unrealized 1970 “Slave” module concept and resurrected by Rob Keeble under the AMSynths banner, the AM1028 isn’t a standalone sequencer. It’s a companion—a CV expansion column that mirrors the eight steps of the Behringer 1027, unlocking deeper modulation pathways without cluttering your rack. The idea is elegantly simple: take the rhythmic spine of the 1027 and branch it into expressive voltage control for other parameters. And it does so with a quiet confidence, sitting at just 8HP wide so you can tuck it right beside the module it serves.

What makes it satisfying isn’t just the added control—it’s how it feels like it was always meant to be there. The green SMD LEDs under light pipes clearly mark the active step, giving you visual feedback that’s subtle but effective, especially in dimly lit setups. Eight precision rotary pots let you dial in voltages per step, and because it’s designed for the Behringer ecosystem, it connects internally via a 12-way IDC ribbon cable—no messy patching just to sync up. But don’t mistake its simplicity for limitation. That single column of eight steps is a focused tool, not a compromise. It keeps the design lean, affordable, and physically compact, letting you place multiple AM1028s close to the modules they modulate. And yes, you can chain them—either with custom cables or via the AMSEQBUS PCB, which offers eight 12-way sockets for building out a full multi-column voltage sequencer if you’re feeling ambitious.

It’s also a love letter to the ARP 2500’s modular philosophy—where sequencers weren’t just for notes, but for sculpting evolving textures across filters, envelopes, and mod sources. The AM1028 delivers that spirit without requiring you to hunt down vintage ARP hardware or solder your own PCBs. It’s accessible, modern, and built with the same “more analog than analog” ethos that defines AMSynths’ lineup. But—and this is important—it only works if you already own a Behringer 1027. There’s no standalone clocking, no gate outputs, no internal timing. This is purely a slave unit, both in name and function. If you’re looking for a full-featured sequencer, look elsewhere. But if you’ve ever stared at your 1027 wishing it could do more, the AM1028 feels less like an add-on and more like a completion.

Specifications

Key Features

Dual-Range CV Outputs for Expressive Control

The AM1028’s most practical innovation is its split CV output strategy: one 2V output optimized for VCO pitch control, and two 10V outputs for modulating filters, amplifiers, and envelope generators. This isn’t arbitrary—it reflects real-world voltage scaling. Most VCOs respond cleanly to 1V/octave, so a 2V range gives you a full two-octave span across the eight steps, making melodic sequences easy to tune and repeat. Meanwhile, the 10V outputs are perfect for sweeping a filter from closed to screaming resonance or driving a VCA from silence to full blast. Having two 10V jacks means you can route the same modulation to both a filter and an amplifier without daisy-chaining or using a buffered multiple, preserving signal integrity. It’s a small detail, but one that reflects deep understanding of how modular players actually patch.

Compact, Chainable Design with Visual Feedback

At just 8HP, the AM1028 avoids the sprawl that often comes with expanded sequencing. Unlike larger sequencers that demand center-stage placement, this module is meant to live in the periphery—right next to your 1027 or tucked beside the filter it’s modulating. The green LEDs, enhanced with light pipes for even glow, provide clear step tracking without being garish. They’re not RGB eye candy, but functional indicators that blend into the ARP-inspired aesthetic. And because multiple AM1028s can be chained, you’re not stuck with just one extra column. Want to sequence three parameters independently across eight steps? Stack three units. Need more steps? Combine with other sequencers via external clocking. The AMSEQBUS PCB option is particularly clever—it acts as a distribution hub, letting you connect up to eight AM1028s (or other compatible modules) in a clean, organized way, avoiding a nest of ribbon cables.

Rooted in ARP’s Lost Legacy

The AM1028 isn’t just a modern utility—it’s a resurrection. It’s based on ARP’s unproduced 1028 “Slave” module, mentioned in a 1970 catalog but never built. The original concept was part of ARP’s vision for a modular system where sequencers could drive multiple voltage-controlled parameters in parallel. AMSynths didn’t just copy the idea—they reimagined it for the Eurorack era, using the Behringer 1027 as a modern stand-in for the ARP 1027. The result feels authentic, not nostalgic. It uses the same front-panel philosophy: minimal labeling, tactile pots, and a focus on immediacy. Even the knobs—available in classic ARP colors like gold and green—are sourced to match the vintage look. This isn’t a clone; it’s a continuation, like finding a missing chapter in a favorite book.

Historical Context

The AM1028 exists because Behringer’s ARP-inspired 2500 series, while comprehensive, left some gaps—especially in advanced sequencing. The 1027 brought back the classic 8-step clocked sequencer, but it only offered one column of control voltages. In the original ARP 2500, musicians often used multiple sequencer modules or external control banks to create evolving patches. ARP even teased a “Slave” module in 1970 that would have expanded the 1027’s capabilities, but it never made it to production. Fast-forward to 2024, and with Behringer showing no signs of expanding the line further, Rob Keeble of AMSynths stepped in. He wasn’t just filling a gap—he was completing a vision. The AM1028 is part of a larger “lost modules” project, where Keeble designed ten previously unbuilt ARP concepts as Eurorack modules. This isn’t fan fiction; it’s engineering archaeology. In a market flooded with boutique reinterpretations, the AM1028 stands out by honoring the original design language while solving a real, current need. It’s not competing with Make Noise or Intellijel—it’s serving a niche within the Behringer 2500 ecosystem, giving users a way to go deeper without going digital.

Collectibility & Value

As a brand-new module released in 2024, the AM1028 isn’t “vintage” in the traditional sense—but it’s already carving a place in the collector-modular world. Units in pristine condition with original packaging and rare knob colors (like gold) are likely to hold value, especially as the Behringer 2500 line becomes a modern classic. At launch, it retailed for around £129 GBP (~$165 USD), and since it requires the 1027 to function, its resale value is closely tied to that module’s availability. On the secondary market, expect to pay between $175–$225 depending on condition and knob color, with gold-knob versions commanding a premium. There are no known failure points—the design is passive and robust, with no onboard processors or complex circuitry. The most common issue would be a loose IDC connection or damaged ribbon cable, both easily fixable. When buying used, check that all eight pots turn smoothly and that the LEDs illuminate correctly across all steps. Also verify that the unit syncs reliably with the 1027—some early adopters reported sync drift with third-party ribbon cables, so stick to AMSynths’ recommended cabling or the AMSEQBUS PCB for best results. For those building out a full 2500-style system, the AM1028 isn’t just a luxury—it’s becoming essential infrastructure.

eBay Listings

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.

Related Models

• AMSynths AM-CP1
• AMSynths AM-CP3
• AMSynths AM1005
• AMSynths AM1006
• AMSynths AM1013
• 4ms Ping
• ADC 27
• 2hp LPG V2
• ALM Busy Circuits MS-014
• ALM AXON-2