SW 6401M BODE RING MODULATOR

Bode Ring Modulator

FUNCTION DESCRIPTION

A ringmodulator is an analog sound modification system that takes two inputs, one a program-signal and the other a carrier frequency, being and produces a single output. The program signal is normally a waveform produced by the output from a microphone (voice) or any other source of signal, while the carrier signal is normally a sine wave. The function of the ring modulator is to produce the sum and difference frequencies of the program signal and carrier signal.
SW 6401 Bode RM.jpg
SW 6401 Bode RM
The SW 6401M is based on the original design of Harald Bode from1967. The design is a circuit involving a ring of diodes and transformers forming a four quadrant multiplier. To accomplish a one unit module, the transformers UTC-A20 have been replaced by smaller vintage UTC SO 15P transformers. The diodes are original NOS 1N485A.

This Module is based on the original design from 1967
MUSICAL APPLICATION

It was probably electronic music pioneer Karlheinz Stockhausen’s use of the ringmodulator that inspired an entire generation of rock musicians. Stockhausen’s Mixture (1964), for example, was written for a ring modulated symphony orchestra. Ringmodulation is often used to simulate the sounds of tuned percussion instruments that produce inharmonic frequency spectra, such as bells and chimes. It can also produce timbres that are difficult to achieve by any other method of synthesis. Among all signal processors, the multipliertype ring modulator takes a unique position since it is capable of converting existing sounds into new sounds with entirely different overtone spectra that do not resemble the original acoustical phenomena.

http://www.synth-werk.com/content/modules