The KMA Machines Active ABY is an active ABY pedal that sends one input to two separate outputs, separately or combined, with what KMA calls noise free switching. It is the mono option in KMA's ABY Series, sitting alongside the passive KMA ABY and the stereo Active STEREO ABY. The pedal is made in Berlin, Germany1.
Silent switching and what it does to your signal
The Active ABY's headline feature is its active silent CMOS-based soft switching. KMA says this heavily reduces mechanical noise, with virtually silent signal bypass. In the company's words, "what it means practically is that the pedal is completely silent in operation," with mechanical switching noises greatly reduced and the loud clicks and pops that mechanical ABY boxes can produce virtually eliminated1.
The pedal features a fully active design along with that active silent CMOS switching, and KMA positions it as an additional offering to its Passive ABY box, which the company says "has graced thousands of rigs the world over"1.
Controls
| Control | What it does |
|---|---|
| A, B and Y footswitches | Send the input to two separate outputs, separately or combined1 |
| Phase switch | Flips the A channel by 180 degrees, which KMA says can prevent signal cancellation and tone issues when combining or splitting signals1 |
KMA says the Active models in the ABY Series also incorporate Phase and Y Direction switches, making them ideal to better level match on combining or splitting signals3.
Power and connections
The Active ABY runs on 9V DC with a center negative 2.1mm plug and draws a maximum of over 55mA1. Because it is an active design, it needs power to operate, so it will not run without a supply.
At over 55mA maximum current draw, the Active ABY needs its own power output on most pedalboard supplies rather than sharing a low-current daisy chain1.
Bypass: true bypass and buffering
KMA lists the Active ABY's bypass type as True Bypass1. At the same time, the company describes the Active models in the ABY Series as featuring "KMA's high quality Buffered Bypass circuit, to maintain tone on even the lengthiest cable runs"3. The two descriptions come from different pages of KMA's own material, so a player weighing long cable runs against pedalboard real estate may want to weigh both statements.
The ABY Series and the stereo version
The Active ABY is the mono counterpart in KMA's ABY Series. For players who need to work in stereo, KMA makes the Active STEREO ABY, which shares the same active silent CMOS soft switching, the same 9V DC center negative power and the same over 55mA maximum current draw, and is also made in Berlin, Germany4.
The stereo version adds an A&B>Y or Y>A&B direction switch, which KMA says allows for precise directionality and use of the device in either direction, plus a 180 degree phase switch that helps to remove mismatches. As with the mono Active ABY, KMA says the phase switch can prevent signal cancellation and tone issues when combining or splitting signals1.
Background and release
The Active ABY is an improved 2025 edition of KMA Machines' AB/Y, which was first featured in 2023. Guitar Pedal X described the AB/Y and Stereo AB/Y as "presumably honed and improved in these 2025 editions," and listed the Active ABY at €79 / £792.
Questions
What is the difference between an active and a passive ABY box?
A passive ABY box simply routes the signal with mechanical contacts, while an active ABY like the KMA Active ABY uses a fully active design with active silent CMOS switching. KMA says this makes the pedal completely silent in operation, greatly reducing mechanical switching noises and virtually eliminating loud clicks and pops. The active models also add Phase and Y Direction switches to help level match when combining or splitting signals.
Is the KMA Machines Active ABY true bypass?
The Active ABY's bypass type is listed as True Bypass on KMA's product page. KMA also describes the Active models in its ABY Series as featuring the company's high quality Buffered Bypass circuit, which it says maintains tone on even the lengthiest cable runs.
What power does the KMA Machines Active ABY need?
The Active ABY runs on 9V DC with a center negative 2.1mm plug and draws a maximum of over 55mA. Because it is an active design, it needs a power supply rather than running passively, so plan your pedalboard power accordingly.
Where is the KMA Machines Active ABY made?
KMA Machines makes the Active ABY in Berlin, Germany. The company describes its ABY Series as created with a focus on durability, reliability, simplicity and hassle-free operation.
Is there a stereo version of the KMA Active ABY?
Yes. The KMA Active STEREO ABY is the stereo counterpart for players who need to work in stereo, while the Active ABY is the mono option. Both share the active silent CMOS soft switching, 9V DC power and a maximum current draw of over 55mA, and both are made in Berlin, Germany.
Sources (4)
- Active ABY, KMA Machines
- Guitar Pedal X, Guitar Pedal X, 2025-11-18
- Introducing our New ABY pedals, KMA Machines
- Active STEREO ABY, KMA Machines
