There’s nothing new about ABY boxes. They’re widely used and a staple accessory in countless setups. But if they are so common, then why—until the release of our passive Stereo ABY—was it so hard to find one in a stereo format that was well-built, noise-free and affordable?This is a question we kept encountering, especially since we work with many stereo devices every day at KMA, and we know many users are just as captivated by the wide sonic possibilities of stereo sound as we are.

So, we built a high-quality stereo ABY switcher for our workshop. It proved so useful that we decided to make the original STEREO ABY available to the world in pedal format.

While our passive boxes are used in thousands of rigs globally, the Active STEREO ABY goes even further—perfect for users who rely on Y-splitting or combining, especially when dealing with signals that don’t always “get along” due to impedance differences between devices. Thanks to KMA’s high-quality active buffer, the pedal can help eliminate level mismatches and even prevent signal loss, especially with long cable runs.

Whether you want to switch or combine a stereo input signal between two destinations, or merge/split two stereo signal sources into one stereo output without loss, the KMA Machines Active STEREO ABY pedal is a reliable tool for your tonal journey. The fate of your stereo signal is in your hands!

Main Features

• Active Stereo / Dual-Mono ABY pedal

• Sends one stereo input to two stereo outputs, individually or combined (¼″ / 6.35 mm jacks)

• Sends two stereo inputs to one stereo output, individually or combined

• 180° Phase switch to correct phase mismatches

• Active silent CMOS-based soft switching for near-silent operation

• Omnidirectional (2-into-1 or 1-into-2 operation)

• A&B>Y or Y>A&B switch for precise routing direction

• Distinct LED colours for instant visual routing indication

• Durable compact enclosure for long-term reliability

• Top-mounted jacks to fit tight pedalboards

• Made in Berlin, Germany

• Powered by optional 9 V PSU (9 V DC, centre –, 2.1 mm, >55 mA)

KMA’s ABY Series is built with durability, reliability, simplicity and hassle-free operation in mind.

The Active STEREO ABY uses a fully active circuit paired with our active silent CMOS switching. While the terminology may sound technical, in practice it means the pedal operates completely silently. This design prevents signal loss and reduces mismatches across various setups. Achieving this form of switching without interference between the audio and switching paths is challenging, but KMA’s implementation greatly minimizes mechanical noise and virtually eliminates unwanted pops and clicks that have long plagued ABY devices.

And yes—the bear’s eyes light up! Beyond the fun visual effect, the three LEDs serve a practical function: giving you instant visual confirmation of your routing.
Red = A, Yellow = B, Blue = A&B.

The A&B>Y or Y>A&B switch allows the pedal to be used in any direction: sending signals to multiple amps, synths or effects—or routing multiple instruments/devices into your chain via the Y channel. The 180° Phase switch flips Channel A to prevent signal cancellation or tonal degradation when combining or splitting stereo signals.