Catalyst Audio built a Eurorack line around Soviet MiG fighter-jet tubes

What is the MIG series?

Catalyst Audio, working with Electroserf, has launched MIG: a full line of vacuum-tube Eurorack modules. So far it covers the core of a voice, a VCO, a VCF, a VCA, a Noise module and a Mixer, and the whole thing was designed from the ground up around a single, very specific part.

That part is the 1j24b (written 1Ж24Б in Cyrillic), an obsolete Soviet subminiature vacuum tube. These were not made for music. They were manufactured during the Cold War for the avionics of Mikoyan-Gurevich fighter jets, the MiGs, hence the name on the panel. Catalyst didn't bolt a tube onto a solid-state design to chase a buzzword. They started with the tube and built the modules to suit it.

Why put a fighter-jet tube in a synth?

Tubes colour sound in a way circuits still get hired to imitate. They add even-order harmonics, a soft compression as you push them, and a thickness on the way into clipping that a lot of producers chase with saturation plugins and outboard. Putting real tubes at the heart of a VCO, a filter and a VCA means that character is baked into the signal path from oscillation onward, not sprinkled on at the end.

The subminiature format is the clever bit. Big bottle tubes are power-hungry and run hot, which is exactly why they're rare in Eurorack, where the power budget is tight and the case is sealed. The 1j24b sips current. Catalyst says the MIG modules run fine on standard Eurorack power supplies, so you can drop tube tone into an existing case without a special PSU or an external brick.

Military tubes built for MiG cockpits, now generating bass in a modular rack. That is the kind of provenance no plugin can fake.

What is the catch?

Supply. Catalyst Audio has roughly 1,500 of these tubes in stock, and nobody is making more. That hard ceiling is why MIG is a limited-edition run rather than a catalogue staple. Once the tubes are gone, the modules that depend on them are gone too, unless a fresh trove of Soviet new-old-stock surfaces, which is exactly the sort of thing that gets harder to find every year.

That scarcity cuts both ways. It means the people who want a full MIG voice should treat it as a now-or-never purchase, and it means the modules carry the built-in collector weight that boutique Eurorack thrives on.