Breath-to-Expression Converter for the Kelfar Technologies BCK-1™ Breath Controller (and Yamaha BC3A™)
Kelfar BCXP Pro Breath Controller to expression converter
BCXP Pro is a revolutionary addition to the world of keyboard technology.  This device allows you to regulate your keyboard’s volume with your own breath, giving it the natural modulations found in all brass and wind instruments.  Rather than having the flat, uniform tones found with common keyboard strokes, the BCXP Pro reads your breath’s pressure and translates it into power for each note you play.  The softer you blow, the lower the volume.  As your breath’s pressure increases, the note becomes louder.  This gives the ramp-ups and trail-offs produced by real wind and brass instruments.

The BCXP Pro is a patented proprietary device that is American made and guaranteed to improve your performances in a way no other keyboard plug-in device can.  All you need is a keyboard with an expression input jack and BCK-1™ by Kelfar Technologies Breath Controller or Yamaha BC3A headset to get started.  By plugging the BCXP Pro directly into your keyboard’s Pedal input, and plugging your BCK-1™ or BC3A headset into the BCXP Pro, you unleash new potential for producing a whole new array of realistic sounds.

The BCXP Pro requires no special software or other devices (besides the headset).  You don’t even need MIDI!  Its simple settings do not require technical skills in order to operate: this is a true plug-and-play accessory.


The BCXP PRO can be connected to most keyboards/synths through the Pedal Input Jack for controlling volume, expression or other assigned parameters.

1/8” input jack to connect to the BCK-1™ or Yamaha BC3A™ and your keyboard with a comparable input array
Input jack for connection to an expression pedal (to merge an additional device)
Linear Response (0-127)
Reverse button for reversing the tip & ring
Two LED indicators: green for full battery, and yellow for low battery warning
Powered by either a 9v battery or DC 9v regulated power supply (not included)

Color: Black
Weight: 5oz/142g (with battery), 4oz/113g (without battery).
Dimensions: 4.94″ x 2.750″ x 1.275
Warranty: 1 year from the date of purchase

Note:  BCK-1™ or YAMAHA BC3A™ not included


BCXP Pro diagram

BCXP PRO Setup/Guide

Supported Instruments and Tested on:

Korg Kronos, Korg M3 series, Korg M50 series, Korg Pa800, Pa2x Pro, Korg Extreme, Korg Triton series, Korg Triniy, Roland JX-305, Roland Fantom series, Roland Fantom G series, Yamaha Motif, Motif Es, Motif XS, XF, Ketron Vega, Ketron Audya, Novation ( we are still testing…)

PRICE: $159.99 + S&H

Out of Stock