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.
The SW 6401M is based on the original design of Harald Bode from 1967. 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 To accomplish a one unit module, the transformers UTC-A20 have been replaced by smaller vintage UTC SO 15P transformers.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.
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.
Input Impedance program input: | 47k ohm |
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Input Impedance carrier input: | 47k ohm |
Output Impedance: | 680 ohm |
Nominal Input Voltage: | 1V RMS (higher levels will lead to distortion which can be an additional interesting effect) |
Gain: | approx. 0 |
Frequency range: | 0,15 kHz to 20 kHz |
Power Requirements: | +15 Volt at + 90 mA |
Depth: | 160 mm |
A frequency shifter is an audio signal modifier which shifts the entire frequency spectrum of the applied signal by a given amount. The Model SW 1630 Bode Frequency Shifter allows the amount of shift to be accurately and continuously controlled over a span of -5000 Hz to +5000 Hz, utilizing voltage and/or manual control. The relationship between the control voltage sum and the amount of shift may be either linear or exponential. Up-shifted and down-shifted outputs, as well as a continuously variable mixture of the two, are available simultaneously and independently. Variable threshold squelch and zeroadjust fine tuning controls are provided.
The Model SW 1630 Bode Frequency Shifter changes the ratios between the frequency components of an audio spectrum, thus producing a variety of novel sound quality transformations. Applications include a wide variety of tone color modification, P.A. feedback suppression, linear frequency modulation, novel tape feedback effects, and the generation of dynamically varying clangorous tones.
In shifting the components of the input audio spectrum by a given amount, the SW 1630 Bode Frequency Shifter changes the original ratios between the overtones and other frequency components of the input signal. Rather than being a transposing device, this instrument is a means for achieving an extremely wide variety of tone color modification. Whether the amount of frequency shift is large or small, static or time varying, or whether the input signal is simple or complex, the processed outputs will generally be musically interesting.
Nominal Input Impedance: | 50k ohm |
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Nominal Input Level: | +2dBm |
Frequency Range: | 30Hz to 16kHz |
Nominal Output/Input gain: | Unity |
Less than 0.1% total hum and noise | |
Variable threshold squelch minimizes apparent carrier bleedthrough due to input signal background noise | |
Accurately shifts input signals over the audio frequency range of: | 30 Hz – 16 kHz |
Amount of shift is continuously variable from | -5 kHz, through zero to +5 kHz |
Amount of shift is accurately voltage variable – either linear or exponential control mode is available | |
Less than 1% total unwanted modulation and distortion products | |
Power requirements: | +/-15 Volt at + 100 mA / -100 mA |
The model 735 was the first Instrument of the BODE Frequency Shifters 7series. Like all frequencyshifters designed for the use in electronic music Studios and or with Synthesizers, it is a unique and powerful tool, capable of changing any sound with a given overtone structure through additive and subtractive frequency shift to a new sound with an entirely different and new arrangement of overtones.
From an electrical point of view it is absolutely identical to the MOOG-BODE 1630 Frequency Shifter. Compared to the BODE 735 MK2 Frequency Shifter it offers less precision in terms of stability but this can be exactly what you need for an organic sound. Comparable to the MOOG 901 and 921 oscillators.
This Module is based on the original design from 1974
Nominal Input Impedance: | 50k ohm |
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Nominal Input Level: | +2dBm |
Frequency Range: | 30Hz to 16kHz |
Nominal Output/Input gain: | Unity |
Less than 0.1% total hum and noise | |
Variable threshold squelch minimizes apparent carrier bleedthrough due to input signal background noise | |
Accurately shifts input signals over the audio frequency range of: | 30 Hz – 16 kHz |
Amount of shift is continuously variable from | -5 kHz, through zero to +5 kHz |
Amount of shift is accurately voltage variable – either linear or exponential control mode is available | |
Less than 1% total unwanted modulation and distortion products |
The model 735 Mark II is, like its predecessor, the model 735, a most sophisticated and powerful signal processor. In some of its typical applications it can change known sounds with a harmonic overtone structure into new sounds with an entirely different and new arrangement of overtones through additive and subtractive frequency shift. It thus contrasts with and complements the known pitch changers (such as the HARMONIZER), which operate with multiplicative frequency shift.
At the MIX output jacks, a mixture of the OUT A and OUT B signals is obtained, which in the center position of the MIX control is that of a ring modulator.
As a keyboard-controlled instrument (1 volt/octave), the 735 Mark II is capable of producing an infinite variety of bell, chime, carillon, wood block, marimba, steel drum and other sounds, maintaining the chosen timbres over the entire playing range.
Due to a revolutionary new design of its patented local oscillator (quadrature oscillator), facilitating frequency shifts down to a fraction of 1 Hz (typically less than 0.05 Hz) the Model 735 Mark II can now be utilized for some very interesting ambience modulation effects.
Furthermore, when inserted in the feedback loop of a delay line, the ”spiraling echo effect“ can be produced. This opens upan unexplored variety of musical applications.
I remember my father telling me that he had completed building his new Bode Frequency Shifter Mark II. This was the unit he built for himself, for his own studio. Soon after, Florian Schneider of Kraftwerk came to visit my father at his home and studio. The Bode family were all big fans and collectors of Kraftwerk music. My father was happy for Florian's visit. He was not planning to sell and part with his new Frequency Shifter. It was a nice visit. He told me, a happy Florian Schneider left with the Bode Frequency Shifter Mark II under his arm.
Peer Bode
Nominal Input Impedance: | 1M Ohm |
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Nominal Input Level: | 0 dBm to +4 dBm |
Frequency Range: | 20 Hz to 20 kHz |
Nominal Output/Input Gain: | unity |
Unwanted distortion and modulation products less than 1% | |
Hum and noise are better than 65 dB below maximum signal level | |
Amount of shift is continuously - 5kHz trough zero to +5 kHz in 4 ranges (5Hz/50Hz/500Hz/5kHz) |
The BODE BARBERPOLE PHASER offers 9 phase stages and various sound manipulation features. The option to insert an additional effect into the feedback loop or one of the two audio pathes is one of them.
The main feature of the BPP/product is infinity phasing. Infinity phasing is a psychoacoustic effect based on the Shepard scale, which was introduced in 1964 by the psychologist Roger N. Shepard. It creates the illusion of an infinitely ascending or descending scale that never exceeds the limit of one‘s hearing.
The combination of the various features like left-right panning or the transfer of a monofonic input signal into a stereo output signal and modulation of the phaser creates a sonic soundstage in the tradition of Harald Bodes ”Klangumformer” principal. If you think you know the sound of a Phaser, you need to listen to the Barberpole Phaser to understand the possibilities of a ”Klangumformer”
Nominal Input Impedance: | 50k ohm |
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Nominal Input Impedance: 50k ohm Nominal Input Level: | +2dBm |
Frequency Range: | 30Hz to 16kHz |
Nominal Output/Input gain. | Unity |
S/N Ratio >60dB | |
Input level control and overload indication | LED responds to a level of 8dB below overload |
V Trigger IN/OUT on the back | |
SEND&RETURN for Feedback and OUT A | |
Power requirements for 5U module: | +/- 15Volt at + 200 mA / -200 mA |