4ms Row Power 35 (2022–)

Name: 4ms Row Power 35
Brand: 4ms Row

A clean, regulated, and protected power solution for Eurorack systems that doesn’t hog your panel space but delivers where it counts.

Overview

If you’ve ever stared down a half-built Eurorack case, wires snaking like overgrown ivy, wondering if your power setup is going to hold up—or worse, fry something—you know how quietly critical a good power module is. The 4ms Row Power 35 doesn’t announce itself with flashy lights or knobs, but it’s the kind of gear that earns loyalty fast. It’s a 4 HP Eurorack power distribution module made by 4ms Company, designed to quietly do one job very well: deliver stable, clean power to a single row of modules. Available since June 2022, it’s positioned as a revision and continuation of the earlier Row Power 30, which had already built a reputation for reliability in modular circles. This isn’t a power supply you show off—it’s the one you forget about because it just works.

The Row Power 35 is built for realism. It doesn’t pretend to power an entire 120HP case by itself. Instead, it’s sized for a typical Eurorack row—anywhere from 84HP to 168HP—making it ideal for multi-row cases where distributed power is smarter than a single centralized supply. It outputs a total of 35W, with +12V @ 1.4A, -12V @ 1.25A, and +5V @ 1.0A, which covers the needs of most module combinations you’d pack into a single row. The rails are separately regulated using high-grade components, a design choice that owners report helps keep cross-talk between modules to a minimum—critical when you’re running sensitive analog oscillators or low-noise filters.

One of the standout practical features is its daisy-chaining capability. With two power supply connectors on board, you can link multiple Row Power 35 modules together and run them all from a single 90-watt laptop-style AC power supply, like the 4ms Power Brick 90W. The manufacturer notes that 3 to 5 Row Power units can typically share one brick, which simplifies cabling and reduces wall-wart clutter. The system stays live on the daisy-chain even when you toggle an individual Row Power off, thanks to an on/off switch that cuts power only to the connected row—handy when you’re swapping modules or troubleshooting without shutting down your whole system.

It’s also built for flexibility. Whether you’re using flying bus cables, a Bus Stick, or a full bus board, the Row Power 35 gives you two 16-pin headers to connect your modules. For those rolling their own enclosures or doing custom builds, the PCB includes blade tabs and solder holes that support large gauge wire or MTA156 connectors—details that speak to the DIY-friendly roots of 4ms as a company. And yes, you can hot-swap rows: plug or unplug the Row Power without powering down the rest of your case. That’s not just convenient—it’s a small but meaningful safety net when you’re deep in a patch session and need to swap out a misbehaving module.

Specifications

Manufacturer	4ms Company
Module Size	4 HP Eurorack format module
Width	4 HP
Depth	27mm (1.1") with power connectors installed.
Power Output	+12V @ 1.4A, -12V @ 1.25A, +5V @ 1.0A
Total Power	35W
Power Input	Powered by laptop-style DC power supply: 2.1mm barrel, positive center, 15V-20V.
Input Requirement	Typically uses a 90-watt laptop-style AC power supply (e.g., 4ms Power Brick 90W)
Connection	5.5 mm hollow female plug, 2.1 mm inside
Polarity	Plus inside
Own power consumption	1.4mA @+12V, 1.25mA @-12V, 1mA @+5V
Compatible case row sizes	suit ed for any typical eurorack row (84HP to 168HP)
Intended load	enough for a typical 84–168HP row of Eurorack modules
Distribution Connectors	Two 16-pin headers for flying bus boards or bus boards
Expansion Headers	CV/Gate Bus headers
Daisy-chain Ports	Two power supply connectors for connecting further Row Power modules or 4ms Pod enclosures
Indicators	Mains switch and control LEDs for +12 V, -12 V and +5 V
Required Accessory	Requires 4ms Power Brick 90 W (or equivalent; not included)
Included accessories	2 M3 Knurlie screws

Key Features

Independent Regulation for Cleaner Power

Each voltage rail—+12V, -12V, and +5V—is separately regulated using high-grade components, a design that helps minimize cross-talk between modules. This isn’t just marketing speak; in practice, it means that a power-hungry digital module on the same row won’t induce noise into a delicate analog VCA or reverb circuit. The result is a quieter, more stable system, especially important in complex patches where signal integrity matters. The Row Power 35 is described by the manufacturer as a “clean, regulated, and protected power solution,” and the separate regulation is a big part of why it earns that label.

Daisy-Chaining Without Compromise

The ability to daisy-chain multiple Row Power modules is one of its most practical features. With two power jacks on board, you can chain additional Row Power units or 4ms Pod enclosures, all running off a single 90W power brick. Crucially, each row remains independently regulated and protected, so a short or overload in one row won’t take down the rest. This modular approach to power distribution scales elegantly: build a 3-row case? Use three Row Power 35s and one brick. The system is designed so that the daisy-chain stays live even when an individual row is switched off, letting you power down a section for maintenance without disrupting the rest of your setup.

Hot-Swappable and User-Friendly

The Row Power 35 supports hot-swapping—meaning you can plug or unplug it from the bus board while the case is powered. That’s a small but meaningful feature for live performers or tinkerers who don’t want to reboot their entire system just to swap a module. The front panel includes a mains switch and individual LEDs for +12V, -12V, and +5V, giving immediate visual feedback on power status. No guessing if the row is live—just glance and go. And since it only consumes 1.4mA @+12V, 1.25mA @-12V, and 1mA @+5V of its own power, almost all of that 35W is available for your modules.

Flexible for Builders and Tinkerers

The PCB is designed with custom installations in mind. In addition to the standard 16-pin headers for bus boards or flying cables, it includes blade tabs and solder holes that support large gauge wire or MTA156 connectors. This makes it a favorite among DIY builders who are rolling their own cases or integrating power into non-standard enclosures. Whether you’re using the Bus Stick, a custom bus board, or direct solder connections, the Row Power 35 adapts without fuss. It’s also compatible with 4ms Pod enclosures, making it a natural fit for compact or portable setups.