The Ekdahl FAR

Introduction

The Ekdahl FAR is a string based electro-acoustic instrument whose main way of generating sound is by utilizing a bowing wheel that rubs against the string and by very precisely controlling the speed of the wheel, emphasizing natural overtones in the string. The bowing wheel is situated on a controllable pivot which pushes the wheel more or less hard into the string in order to affect both volume and harmonic content. To further extend the capabilities of the instrument it also has a hammer, a variable mute and a electromagnetic pickup. While the audio path on The Ekdahl FAR is entirely analog-acoustic, the internals of the instrument is a highly sophisticated network of sensors, motors and a built-in computer running a complex firmware allowing for precision control and interfacing via USB-MIDI, MIDI, CV and USB-Serial.

Like all Knas instruments, the Ekdahl FAR - while a new and somewhat experimental concept - can be used for any regular musical composition and expression, but also allows for deep explorations of naturally occuring overtones within the realms of digital precision control and repeatability. The instrument is designed to perform excellently whether being in an improvisational setting, or being sequenced. All aspects of The Ekdahl FAR can be mapped to respond to any avaliable control mechanisms (USB, MIDI, CV etc.) and emphasis has been put on configurability and modification both from a software and a hardware perspective.

The Configuration utility

Main unit

• Dimensions: 117mm x 57mm x 158mm / 46" x 2¼" x 6¼" (max)
• Weight: 3.6Kg / 8lb
• Power supply: 12V DC, 2A center positive barrel plug
• Audio output: 1Vpp max
• USB: Micro-B connector @ USB 2, presents a USB-SERIAL and USB-MIDI device
• MIDI: TRS 3.5mm Type A, MIDI In only
• Bowing range / Motor frequency range: ~30 Hz - 650 Hz
• Max string length:

Control box

• Dimensions: 136 x 153 x 42mm / 5⅜" x 6" x 1⅝" stand alone (max), 22HP x 25mm deep when mounted as euro rack
• Weight: 500g / 8oz
• Max CV/Gate voltage in recommended: 12V
• Voltage range for each CV input:
  • Harmonic V/Oct (A0) - 0 - 4V / 4 octaves (1327.716/V) (Harmonic knob turned to 0)
  • Harmonic shift (A1) - +/-2.425 (No attenuation)
  • Pressure (A3), Hammer (A4) & Mute (A7) - 0 - 3.6V (No attenuation)
  • Gate (A5) - 0 - 3.3V
• ADC resolution: A0 - A3 @ 16-bits, A4 - A7 @ 12-bits
• Input configuration: A4 and A5 configured as trigger-inputs which reads new data once when the input voltage has passed a certain threshold, all voltages under the threshold are recorded as 0. All other inputs are configured as regular inputs that are continuously read and their values recorded.
• CV input ring voltage/current for expression pedals: 5V @ 5mA / jack
• Audio output: 10Vpp (+/-5V)

Command reference