4ms

Repair, Service, and Parts

4ms repair, service, and parts

Acme Revival is an independent repair network that operates separately from the manufacturers whose devices we service. Our independence enables a repair model that exists beyond manufacturer-controlled strategies, while preserving the ability to work with manufacturers where appropriate.

Portland, Multnomah County, Oregon, USA
Manuf. Location
≈ US $1.86M
Annual Revenue (est)
Modular synthesizers
End Use Segment

4ms Company is a U.S. boutique electronic musical-instrument manufacturer specializing primarily in Eurorack modular synthesizer hardware. Founded by Dan Green, the company evolved from experimental effects pedals and tabletop noise devices into a well-known Eurorack maker producing oscillators, sequencers, clock and modulation modules, samplers, delays, filters/resonators, mixers, power systems, and compact Pod modular cases. Its better-known designs include the Spectral Multiband Resonator, Dual Looping Delay, Ensemble Oscillator, Spherical Wavetable Navigator, MetaModule, Catalyst Sequencer, Rotating Clock Divider, and Shuffling Clock Multiplier. 4ms emphasizes original circuit design rather than reproductions of classic synthesizer circuits, and it also supports DIY builders through kits and open-source designs.

2 Most Seen Failures:

No Power / Module Fails to Start

4ms Eurorack modules can develop a complete no-power condition caused by power-input faults, damaged regulators, supply-rail problems, or failed board components. Repair records specifically document 4ms modules arriving with a "not powering up" complaint.

microSD Card Read / Playback Failure

Sampler and Stereo Triggered Sampler units can stutter, fail to load samples, lose sample libraries, or behave erratically when the microSD card becomes slow, corrupted, incompatible, or worn. 4ms specifically identifies microSD performance as a cause of looping-playback stuttering.

Clock Division / Multiplication Calibration Drift

Quad Clock Distributor units can develop incorrect Div/Mult knob positions where the selected division or multiplication is displaced by one or more steps. 4ms identifies recalibration as the normal corrective action for this condition.

1V/Oct Pitch Tracking Calibration Error

Ensemble Oscillator, Spherical Wavetable Navigator, STS, and other pitch-controlled digital modules can develop inaccurate tracking, scaling, or tuning across octaves. Recalibration of the CV input typically restores correct 1V/oct response unless an analog input-stage fault is present.

Firmware / Bootloader Update Failure

Digital modules including the Dual Looping Delay, SMR, SWN, STS, and Ensemble Oscillator can fail to boot correctly or behave abnormally following an interrupted or unsuccessful firmware update. 4ms documents update failures requiring the loading procedure to be repeated and, in some cases, a factory reset.

Audio Channel Dropout / No Effect Processing

Dual Looping Delay and other multi-channel DSP modules can develop a channel that passes dry audio but no longer processes the expected delay or effect. Users have reported individual DLD channels becoming inactive or failing to engage while the other channel continues operating.

Power-Rail Hum / Excessive Noise

Row Power-powered systems can exhibit excessive hum, buzz, or supply-related noise when the power system, grounding, distribution connection, or attached load is abnormal. Power problems can also interfere with startup and firmware-loading behavior on sensitive digital modules.

Intermittent Pots, Sliders, Buttons, Encoders, or Jacks

Heavily used 4ms modules employ numerous PCB-mounted potentiometers, sliders, illuminated buttons, rotary encoders, switches, and 3.5 mm jacks that can eventually become intermittent or mechanically worn. Symptoms include jumping parameter values, controls that respond only in certain positions, unreliable triggering, or intermittent audio/CV connections.

DIY Kit Solder / Assembly Failure

4ms DIY versions of the PEG, RCD, SCM, Sampler, Looping Delay, Swash, and related products commonly develop faults when solder joints, IC orientation, diodes, headers, jumpers, or polarized capacitors are installed incorrectly. Typical symptoms are no power, dead channels, missing controls, unstable operation, or sections of the circuit failing completely.

1 Acme Revival offers repair, service, and part rebuild opportunities for most 4ms devices.

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  1. 1 Repairs are performed on a best-effort basis. Acme Revival utilizes a network of sophisticated technicians and engineers with diverse service offerings; despite this, factors that influence the repair outcome may ultimately prove unsuccessful. Acme Revival makes no claim that it can, guarantee a repair before your device is sent in for diagnostic evaluation; even then, repair and diagnostic work are not mutually exclusive. Despite well-intentioned quoting, repairs may still prove unsuccessful.
  2. 2 Per information known, researched and collected by Acme Revival and its systems at time of page publishing (September 14, 2026).
  3. *Information regarding this manufacturer/brand/organization is estimated with information collected and known to Acme Revival. This information is intended to provide insights into the spotlight entity, however may not be accurate— information is strictly of estimate nature only.
  4. **The model list shown here may not be an all-inclusive list of the EcoFlow product range. Model list has been derived per information known, researched and collected by Acme Revival and its systems for the US market.