Feedback Modules The Matrix: a 4×4 matrix mixer with offsets and inverted outputs

Feedback Modules put The Matrix on sale on 8 November: a 4×4 matrix mixer for Eurorack developed with CMS-LAB. The module is 26HP wide and adds two things to the usual grid of sixteen knobs that rarely come together: an adjustable offset on every output and an inverted output next to each normal one. It sells for €160 excluding VAT in the maker’s shop. This article is based on the official Feedback Modules product page and its user manual.

What a matrix mixer does

A regular mixer sums several inputs into one output. A matrix mixer sends every input, at a level you choose, to each of several outputs: four inputs and four outputs means one control per crosspoint, sixteen knobs in all. In a modular system it acts as mixer, splitter and meeting point between audio and control voltages at once. The manual states that The Matrix takes audio, CV and DC voltages alike; control voltage itself is covered in our guide CV and Gate explained.

What The Matrix adds to the grid

Sixteen unipolar knobs

Inputs IN1 to IN4 sit along the top of the panel, outputs on the right. Each knob sets how much of one input reaches one output, from nothing (fully counter-clockwise) to full level (fully clockwise). The knobs are unipolar: none of them flips a signal’s phase on its own, which is what the inverted outputs are for.

One offset per output, −8 V to +8 V

Every output has an offset knob that adds a DC voltage from −8 V to +8 V, with an ON/OFF switch to engage or bypass it without losing the setting. On a CV, the offset shifts the modulation range; on audio, it adds asymmetry ahead of a distortion or wavefolder. With nothing patched in, an output with its offset on becomes a plain fixed voltage source.

A normal and an inverted output

Each output has two jacks: O+, in phase with the mix, and O−, phase-inverted. One envelope can open one filter while closing another, with no extra inverter module. Feedback Modules also points to patching outputs back into inputs for feedback patches, the idea the brand is named after.

Format and power

At 25 mm deep it fits skiff and travel cases. To weigh the width and current draw against a case budget, see our guide Eurorack explained: choosing your first case.

Who it is for

The Matrix is aimed at modular players who already have a few sources and destinations and want a central routing hub: blending two LFOs into a filter, scaling one envelope to three destinations, or building feedback loops between oscillators. It is not a first module: 26HP for a utility is a large slice of a small 84HP case, and it gets more useful the more modules there are to connect.

Price

Feedback Modules lists The Matrix at €160 excluding VAT in its online shop, with the destination country’s VAT added at checkout. The maker shows it as in stock.

How it compares

The benchmark is still the Doepfer A-138m, also a 4×4 matrix for audio and CV. Going by the two spec sheets, they make different choices:

• the Doepfer A-138m offers a bipolar mode per column, where each knob inverts the signal left of its centre position; its offsets are limited to the top row and depend on an internal jumper;
• The Matrix keeps unipolar knobs, which are easier to set by ear, but gives every output a front-panel offset and a permanent inverted output, so you get a signal and its inverse at the same time, which the Doepfer’s bipolar mode cannot do on a single output.

In practice The Matrix replaces a CV mixer, four offset generators and four inverters, at the cost of 26HP in one block. More mixing and modulation modules are gathered in our Eurorack modules section, including the WMD Modbox MKII, a natural source for a matrix like this one.

Listen

Feedback Modules links to a demo by Strat-1: detuned oscillators, noise, a filter and a 1-bit delay run through the matrix.