by Robin Vincent | Approximate reading time: 1 Minute
4MS Percussion Interface + Expander

4MS Percussion Interface + Expander  ·  Source: 4MS


The Percussion Interface and Expander can generate gates and envelopes from any audio source but particularly suited to plugging in acoustic drums and percussive sounds to control your Eurorack from your drum kit.


Percussion Interface + Expander

The PI+EXP are a pair of modules that are sold together to pull in audio and output gates and envelopes. You can use it as a pre-amp for microphones and instruments which then get their envelopes followed and transients gated into useful control voltages. We first saw them back in April but now they are ready for release.

The Percussion Interface has a single input which outputs a gate when sound is pumped in. It also generates an envelope and an inverted envelope that either follows the audio or makes use of its own Sustain and Decay levels. A Sensitivity knob helps keep things under control.

The Expander section adds three gain stage options and a nice fat 1/4″ jack socket to better accommodate a microphone, guitar or other audio equipment. It also brings in another envelope and inverted envelope with individual trim.


They are not much to look at but when you see them coupled together with a drummer you get a glimpse of what this module could mean for your Eurorack.

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The PI+EXP will be available at the end of October for $165.

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4MS Percussion Interface + Expander

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