Frequency Shifter

Frequency Shifter

Frequency Shifter:

  1. Hilbert Transformation Filter for incoming signal, DOM fitler (B. Hutchings, Haible)
  2. Two precision multiplier for sin / cosin transformation (AD633)
  3. Mixer for up- down shifts, balance between Ringmodulation and Single Sideband Superession.

For work you need a quadrature VCO. A Doepfer A110-4 is  perfect it produce sine and cosine wave, or a state vatriable filter is also possible (s/csine at LP/HP).

The RMO knob allows continus shift between ringmoduation (only one multiplier) to single side band supression. You can creat interest sound inbetween and enables you to tune exact SSS balance for your signal. The intupt mixer allows you to insert a digitaldelay for delayed shifts.

Moduations VCO: For up or dwon shifts the phase must be inverted. Doepfers A110-4 produces sine/cosine and shifts phase with LFrq poti. Modulation for LinFrq and XFM for extraordinary shift sounds get possible. Basic desing of A110-4 was intended to use in FS-systems (H. Walmsley).

Module need 10hp and 50mm depth.

Demo:

Manual and LFO up-down shifts

 

Frequency Shifter
Frequency Shifter and A110-4 by klangbaukeoln

Frequency Shifter

Frequency Shifter

90 degree phase shift of a sine wave with DOM filter network.

Phase shifting network, called DOM filter, is a precise 12 stage filter and is measured manually to produce shifts over a long range.