Currently available at Analogue Haven.this circuit was originally utilized in the generation of single side band modulation; a military developed radio communications technology. a program (speech, data) would be mixed with a high frequency carrier waveform using this circuit. after filtering an rf amplifier would be used to broadcast the transmission. at this point the signal could be said to be modulated, sounding unintelligible. at the receiving end, this circuit could again be used to demodulate the radio transmission by re-introducing a carrier waveform of the same shape and frequency used to create the transmission. as you can imagine, some cool distortions happen on account of the inadequacies of this technology, variation in the two carrier waveform generators (both frequency and shape), signal levels and of course, interference. reclaimed for artistic purposes by harold bode (and perhaps others) reclaimed this technology for artistic purposes in the early 1960's (utilizing carrier waveforms in the audio range instead), and bob moog (in collaboration with bode) incorporated it into his modular synthesizer systems in the 70's. by then the design was pretty different and they were calling it a "ring modulator" possibly for the "diode ring" configuration originally utilized or perhaps they knew it was a more appealing name that, to some degree, described the clangorous, bell like sounds a single iteration of the circuit was capable of creating.
the moddemod features 2 identical circuits that may be used together or individually. when using them together there is no need patch the output of circuit 1 to the input of circuit 2 as they are internally patched when nothing is inserted at the output of circuit 1 and the input of circuit 2. i worked very hard to minimize carrier bleed. the amount varies from unit to unit and even circuit to circuit within each unit. however, all units match or better the level of bleed you hear in most ic based ring modulators. for this type of circuit, that is very good!
to use this module you will need a minimum of 2 signal sources. 1 will be the program. this signal is inserted at the program input (sockets 1 or 4). the 2nd is the carrier, and it should be inserted at the carrier input (sockets 2 or 5). the outputs are at sockets 3 and 6. by varying the frequency, shape and level of these signals, many different timbres may be heard.
this module is a 4hp wide euro-rack module that consumes no current.
a fun movie about the moddemod."
YouTube via MAKEN0ISE
audio:
the sound is way out, just listen!
something percussive
something else percussive
Is this a CGS real-ring modem?
ReplyDeletethat was my first thought.
ReplyDeleteIt is a similar design. I am using different components and a different grounding scheme. The end result is better carrier suppression and, in my opinion, a better sound. Otherwise I would not put my name on it!
ReplyDeleteI have listened to every ringmod I could build or buy. The modDemod is MY favorite. I auditioned several different transformers and all SUITABLE diode types. I developed a very accurate component matching technique to ensure excellent carrier suppression.
Perhaps somebody will someday better the modDemod... I hope they do! Until then,
Tony
Make Noise
am I to understand the demodulation circuit is the same as the modulation circuit?
ReplyDelete