The Oscillator Devices Garbage Collector Mini is a MIDI to expression converter and MIDI footswitch emulator: a small box that listens to MIDI and drives the expression pedal inputs and external footswitch inputs on your effects devices1. If a pedal, amp or rack unit has a jack for an expression pedal or a tap tempo switch but no MIDI of its own, the Garbage Collector Mini sits in between and translates. Each of its TRS outputs carries two switches, so one cable can cover two footswitch functions on the connected gear1.
It is the smallest member of the Garbage Collector family, which also includes the Garbage Collector v3, a larger unit with more jacks2. The Mini is developed and handbuilt by Oscillator Devices in Germany1.
What it does for a player
The core job is bridging two worlds. Many effects devices accept an expression pedal or an external footswitch through a 1/4 inch stereo jack but have no MIDI input, which locks them out of a MIDI-based rig. The Garbage Collector Mini receives MIDI and outputs the equivalent signals on its TRS jacks, so a MIDI controller, sequencer or switcher can move a pedal's expression parameter or trigger its tap tempo, bypass or preset functions12.
The maker describes it as a MIDI to expression converter with up to two expression outputs, and as a footswitch emulator with two switches per TRS1. The same 1/4 inch stereo jack sockets work in both roles, as expression outputs or as MIDI controlled footswitches2.
A firmware feature added for the Mini v2, from firmware version 3.5, is MIDI Clock to EXP: the unit can translate MIDI Clock data into expression pedal positions, letting tempo itself drive an expression parameter23.
Controls, setup and connections
The Mini keeps its hardware minimal. A multicolored LED gives status indication, and the unit stores presets with a choice of start configuration1.
- Config switch: a small hole on the back contains a switch used to set the MIDI channel and to test the outputs without a MIDI controller connected2
- MIDI connection: a 1/8 inch (3.5 mm) stereo jack plug is used for MIDI2
- MIDI channel: selectable1
- MIDI Thru: not included2
- AC switching: supported2
A user manual covering the Garbage Collector v3 and Mini, dated October 2026, is available from Oscillator Devices as a PDF2.
Mini versus Garbage Collector v3
The Mini is the compact option in the range. The Garbage Collector v3 offers twice the connectivity in a slightly larger box24.
| Mini | v3 | |
|---|---|---|
| TRS outputs | 1 | 2 |
| EXP outputs | 1 | 2 |
| EXP inputs | 2 | 4 |
| Switches | 2 | 2 |
| AC switching | Yes | Yes |
| MIDI Thru | No | No |
| Enclosure | 54 x 41 x 24 mm | 69 x 54 x 24 mm |
Both are handbuilt in Germany in anodized aluminum enclosures, and both have selectable MIDI channels124. The v3's dimensions are also listed as 69 x 58 x 24 mm on its product page, which differs slightly from the 69 x 54 x 24 mm figure on the series page24.
The Mini's footprint is listed as 54 x 24 mm on its product page, while the series page gives the full enclosure as 54 x 41 x 24 mm without sockets. The maker's own pages give both figures, so plan board space using the larger enclosure measurement12.
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Oscillator Devices
Questions
What does the Garbage Collector Mini do?
It is a MIDI to expression converter and MIDI footswitch emulator. It takes MIDI messages and outputs them as expression pedal signals and footswitch presses over 1/4 inch TRS jacks, so a MIDI controller can operate effects devices that only have expression pedal inputs or external footswitch inputs, such as tap tempo.
Can the Garbage Collector Mini act as a tap tempo switch?
Yes. One of its roles is emulating external footswitches, and the maker names tap tempo as an example. Each TRS output carries two switches, so a single cable can cover two footswitch functions on the connected device, triggered from MIDI.
How many expression outputs does the Garbage Collector Mini have?
The maker describes it as a MIDI to expression converter with up to two expression outputs. Its single TRS output jack carries two switches per TRS, and the unit also has two expression inputs, so the exact count depends on how the jacks are configured.
Can you choose the MIDI channel on the Garbage Collector Mini?
Yes. The MIDI channel is selectable, set through a small switch on the back of the unit reached through a hole in the enclosure. The same switch is also used to test the outputs without a MIDI controller connected.
How big is the Garbage Collector Mini?
The maker gives a footprint of 54 x 24 mm, with a full enclosure of 54 x 41 x 24 mm not counting the sockets. It weighs 0.065 kg, roughly the size of a large stomp switch, and fits in tight spaces on a pedalboard.
Where is the Garbage Collector Mini made?
It is developed and handbuilt by Oscillator Devices in Germany, in an anodized aluminum enclosure with Amphenol jack sockets.
Sources (4)
- Garbage Collector Mini, Oscillator Devices
- Garbage Collector, Oscillator Devices, 2026-10-01
- Firmware Updates, Oscillator Devices
- Garbage Collector v3, Oscillator Devices
