Acousti-MIDI Conversion

Acousti-MIDI Saddle Conversion

BGF has discovered how to merge a Kahler bass tremolo system with acoustic and MIDI saddles that can track and sound as accurate as the best performing keyboard synthesizers on the market.

This is what many musicians have been asking the industry for over the past 25 years – Can you make my Kahler piezo/MIDI compatible? By developing proprietary saddle pieces that integrate Graphtech’s Acousti-Phonic Systems; piezo elements and Hexpander Systems; along with the original Kahler saddle set, we can now provide these retrofits and installations.

Acousti-Phonic Modular Pre-amp

For studio-quality acoustic sound from your electric bass.

  • captures the natural acoustics of your electric bass — hear the sound of the wood!
  • can be amplified or recorded directly
  • eliminates feedback or mic placement problems associated with an amplified upright bass.
  • automatically detects and selects mono (single amp) or stereo (dual amp) operation
  • onboard ghost pickup volume control to adjust the magnetic/acoustic mix
  • auxiliary 9v – 18v power for active mag pickups  – eliminates the need for two sets of batteries
  • included jack shuts off all on-board devices when 1/4″ cable is unplugged


Hexpander MIDI Interface

Adds MIDI capability to almost any bass. Interface your bass with pitch-to MIDI converters by Roland and Axon.

  • Fast, accurate tracking
  • Low-latency design perfectly complements today’s state of the art pitch-to-MIDI converters
  • Operates with the latest MIDI converters and Virtual bass systems: Roland V-Bass, and more
  • Add the ghost Acousti-Phonic pre-amp and/or optional switches at any time by simply plugging them in…no rewiring or soldering
  • Optional plug-in MIDI Volume, Momentary Up/Down Program Selector Switch (S1/S2) and QuickSwitch (MIDI/both/mag acoustic) for an infinite palette of tonal possibilities
  • Optional pin-7 wiring harness available for accessing a summed piezo signal


The Acousti-Phonic Pre-amp and Hexpander MIDI Interface can both be used as stand-alone systems, or can “piggy-back” on each other for a complete set of features. Optional Plug-in-Switches allow you to flip between magnetic, acoustic or hex outputs, or blend the three for an infinite palette of tonal possibilities.

This conversion is available with our proprietary saddle kit and the rearward Kahler bass tremolo for four, five, and six string basses.

Note: There most likely will be cavity routing involved depending upon your choice of options.

Please call or email for custom options and pricing.