The AMT EX-50 is a passive mini expression pedal from AMT Electronics, part of the maker's series of compact pedals. Being passive, it needs no power of its own: it works by varying the resistance of a 10kOhm potentiometer and sending that control signal to whatever device it is plugged into, such as a delay's time control, a multi-effects unit's parameter, or another expression-ready pedal1.
Controls and outputs
The pedal keeps its control set small, which is typical of a passive expression design21:
- Pedal rocker: sweeps the 10kOhm potentiometer to send the control signal1
- Normal/inverted switch: flips the direction of the sweep3
- TRS output: connects to devices that expect a stereo (tip-ring-sleeve) expression cable1
- TS output: connects to devices that expect a mono cable1
The dual outputs are the EX-50's most distinctive feature. AMT Electronics describes the TRS and TS jacks as a way "to control two different devices simultaneously"1, and Premier Guitar's expression pedal buying guide likewise noted that it "houses dual outputs (TS and TRS)"3. In practice that means one EX-50 can, for example, drive a TRS-wired multi-effects pedal and a TS-wired device at the same time from a single rocker.
Normal and inverted modes
Expression inputs are not wired the same way across all makers: on some devices, toe-down sends the parameter up, on others it sends it down. The EX-50's switch for normal or inverted operation addresses that. Premier Guitar's guide, covering expression pedals broadly, highlighted this exact feature: "a switch for normal or inverted operation, making it capable of handling a wide range of expression-ready pedals"3. If a connected pedal responds backwards to your foot, flipping the switch corrects it without recabling anything.
Size, build and price
The EX-50 is built as a mini pedal: 110 x 62 x 58mm and 0,6 kg, in a metal body1. That footprint suits a crowded board where a full-size expression pedal would take up too much room, and it sits alongside AMT's other compact designs such as the AMT EX-10F-II. Premier Guitar's 2021 buying guide listed it at $129 street3.
Because the EX-50 is passive, it draws no current and needs no battery or supply. Make sure the device you connect it to actually accepts an expression pedal input; a passive pedal does nothing on its own.
Where it fits
As an expression pedal, the EX-50 does not make sound itself. It remote-controls a parameter on another pedal or rack unit, the way a wah or volume pedal controls a sweep, but for whatever parameter the host device exposes. Its 10kOhm pot value is the specification to check against a host device's requirements, since some expression inputs expect a particular pot range to track the full sweep correctly1.
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Questions
Does the AMT EX-50 need power?
No. The EX-50 is a passive expression pedal, so it carries no battery or power supply of its own. It works by varying the resistance of its 10kOhm potentiometer and sends that control signal to the device it is connected to, which means it also adds nothing to your pedalboard's current draw.
Can the EX-50 control two devices at once?
Yes. The EX-50 has both a TRS and a TS output, and AMT Electronics describes them as a way to control two different devices simultaneously. Because the two outputs are separate jacks rather than a single splitter, you can connect one device on a TRS cable and another on a TS cable at the same time.
What does inverted mode do on the EX-50?
The EX-50 has a switch for normal or inverted operation. In normal mode, rocking the pedal forward sends the control signal in one direction; inverted mode reverses that direction. Premier Guitar's buying guide noted the switch makes it capable of handling a wide range of expression-ready pedals, since different makers wire their expression inputs differently.
What is the EX-50's potentiometer value?
The EX-50 uses a 10kOhm potentiometer, according to AMT Electronics' product page. That value matters because some expression inputs expect a specific pot range to read the pedal's position correctly across its full travel.
Where can I find the EX-50 manual?
AMT Electronics publishes the EX-50 manual in English as a PDF on its website, at amtelectronics.com/new/manuals/EX-50-promo-V2-ENG.pdf. The link is also listed on the RockBoard PedalPedia entry for the pedal.
Sources (3)
- AMT EX-50, AMT Electronics, 2026
- EX-50 by AMT Electronics, RockBoard PedalPedia, 2026
- Tools for the Task: Expression Pedals, Premier Guitar, 2017-05-17
