PS110 – Wave Converter

by Antti Pussinen and Wolfgang Spahn

This is the wave shaper board for our Paper-Synthesizer 110 - VCO. The waveshaper converts saw wave to sine, square and triangular waves. It also ads and input and control for linear frequency modulation and pulse width modulation for square output.

The wave shaper takes the saw wave of the oscillaotr core and makes other waveforms on the same frequency. Triangle wave is what you would expect from a tri oscillator.

Square wave is an analog squ osc with sharp peaks in vertical parts of the wave, making it super crispy sounding. It also has an pulsewidth potentiometer and cv input and attenuation for pwm.

Sine wave is not the purest available but a cool sounding, bit squarish sound with low 1st harmonic content, but harmonics increase on higher harmonic frequencies.

The board is based on the Formant Pro, Modulares Sound System MMS2000, Hans-Joachim Helmstedt - Elektor Verlag - ISBN 3-89576-099-4.


Audio Examples

Paper-PCB

Schematic

(a Formant Pro modification)


Parts

  • resistors: 2x 470 Ohm, 2x 1K, 1x 1.8 K, 1x 4.7 K, 1x 6.8 K, 2x 10 K, 1x 14 K (2K + 12K), 1x 15K, 1x 23K (11K + 12k), 1x 30 K, 1x 39 K, 1x 47K, 3x 100 K, 1x 220K, 1x 280K (220K + 56K)
  • transistors: 1x BC547, 1x BC557
  • 1x Elko 4.7µF 35V
  • 2x diode 1N4148
  • 1x LED 2mA 3mm
  • 1x IC-socket 14Pin
  • 1x OpAmp TLO74
  • pin strips 7 Pins
  • pin header length 38mm 7Pins
  • potis: 2x 220K lin, 1x 100K log
  • trimpoti: 1x 25K, 3x 100K
  • 5x mono mini Jack sockets


~~DISCUSSION~~