AMSynths AM1028 Sequential Volts (2024–)
An 8HP Eurorack expander for the Behringer 1027, with three precision CV outputs and LED step tracking. It fills a gap in a 2500-style rig.
Overview
Say a sequencer controls pitch but leaves the filter and amp static. That is the gap the AM1028 fills. It comes from ARP's unrealized 1970 "Slave" module concept, revived by Rob Keeble under the AMSynths banner. It is not a standalone sequencer. It is a companion, a CV expansion column that mirrors the eight steps of the Behringer 1027 and sends them to other parameters. It is 8HP wide, so it sits right beside the module it serves.
The green SMD LEDs sit under light pipes and mark the active step. That helps in dimly lit setups. Eight precision rotary pots set the voltage for each step. Since it is designed for the Behringer ecosystem, it connects internally with a 12-way IDC ribbon cable, so there is no patching needed to sync up. The single column of eight steps keeps the design lean, affordable and compact, so you can place multiple AM1028s close to the modules they modulate. You can chain them with custom cables or with the AMSEQBUS PCB, which has eight 12-way sockets for building a full multi-column voltage sequencer.
The AM1028 follows the ARP 2500's modular idea, where sequencers were used for more than notes. They shaped textures across filters, envelopes and mod sources. This module delivers that without hunting down vintage ARP hardware or soldering your own PCBs. It follows the same "more analog than analog" approach as the rest of the AMSynths lineup. It only works if you already own a Behringer 1027. There is no standalone clocking, no gate outputs and no internal timing. It is purely a slave unit, both in name and function. For a full-featured sequencer, look elsewhere.
Specifications
| Manufacturer | AMSynths |
| Production Years | 2024– |
| Module Type | Eurorack Expander Module |
| HP | 8 |
| Depth | Approx. 40mm (varies by build) |
| Current Draw | Not specified (low power, passive design) |
| Control Voltage Outputs | 1 x 2V range (for VCOs), 2 x 10V range (for VCFs, VCAs, envelope gens) |
| Step Count | 8 steps |
| Step Indication | Green SMD LEDs with light pipes |
| Connection to 1027 | 12-way IDC ribbon cable (internal) |
| Expandability | Multiple units can be chained via custom cables or AMSEQBUS PCB |
| Potentiometers | 8 high-quality rotary pots for step voltage adjustment |
| Knob Options | Available with green, gold, blue, or red ARP 2500-style knobs |
| Original Price | £129 GBP (approx. $165 USD at launch) |
| Weight | Approx. 150g |
| Dimensions | 40.3mm height x 38.5mm depth x 108.3mm width |
| Compatibility | Requires Behringer 1027 Clocked Sequential Control module |
| Function | Sequential control voltage expander (slave to 1027) |
Key Features
Dual-Range CV Outputs for Expressive Control
The CV outputs are split: one 2V output for VCO pitch control, and two 10V outputs for filters, amplifiers and envelope generators. Most VCOs respond to 1V/octave, so a 2V range gives a two-octave span across the eight steps, which makes melodic sequences easy to tune and repeat. The 10V outputs can sweep a filter from closed to screaming resonance or drive a VCA from silence to full blast. Two 10V jacks mean the same modulation can go to both a filter and an amplifier without daisy-chaining or a buffered multiple, which preserves signal integrity.
Compact, Chainable Design with Visual Feedback
At 8HP, the AM1028 avoids the sprawl that often comes with expanded sequencing. It is meant to live in the periphery, next to the 1027 or beside the filter it is modulating. The green LEDs, with light pipes for even glow, give clear step tracking without being garish. They are not RGB, just functional indicators that suit the ARP-inspired look. Multiple AM1028s can be chained, so three units sequence three parameters independently across eight steps. For more steps, combine with other sequencers via external clocking. The AMSEQBUS PCB works as a distribution hub, connecting up to eight AM1028s (or other compatible modules) without a nest of ribbon cables.
Rooted in ARP’s Lost Legacy
The AM1028 is 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 reimagined it for Eurorack, using the Behringer 1027 as a modern stand-in for the ARP 1027. It uses the same front-panel approach: minimal labeling, tactile pots, and a focus on immediacy. The knobs are available in classic ARP colors like gold and green, sourced to match the vintage look.
Historical Context
Behringer's ARP-inspired 2500 series 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 reached production. In 2024, with Behringer showing no signs of expanding the line further, Rob Keeble of AMSynths stepped in. The AM1028 is part of a larger "lost modules" project, in which Keeble designed ten previously unbuilt ARP concepts as Eurorack modules. It does not compete with Make Noise or Intellijel. It serves a niche within the Behringer 2500 ecosystem, for users who want to go deeper without going digital.
Collectibility & Value
The AM1028 was released in 2024, so it isn't "vintage" in the traditional sense. 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). 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, 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.
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