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 Schematics / Modulo Magic By Ken Stone Modulo Magic by Ken Stone , page dedicated to this circuit is here : http://www.cgs.synth.net/modules/cgs40_modulo_magic.html ,description given by Ken on the site : A CV and signal processor based on the mathematical modulo principle In the mathematical world, modulo gives the remainder after an integer division. For example 7 divided by 4 would give a result of 1, with 3 remainder, so 7 modulo 4 would be 3. 11 modulo 4 would also be 3, as would 15 modulo 4 and so on. This module allows a similar principle to be applied to a voltage. If the modulo (Step Initiation CV) is set at 1 volt and the step size also set at 1V, the output would follow the input while the input remained between 0V and 1V. As soon as 1V was reached, 1 volt would be subtracted from the output, so for an input varying between 1V and 2V, the output would track at a volt less, i.e. between 0V and 1V again. There are 8 stages to the module, so this process would occur again as the input voltage passed 2 volts and so on up to 8 volts. Of course, the Step Initiation CV and Step size are adjustable. This can be used to constrain a CV to a single octave or similar interval as needed. Now consider if the step size is greater than the Step Initiation CV (SICV) - each time a multiple of the SICV is passed, the greater step size voltage will be subtracted, resulting in successive negative offsets to the output. A smaller step size will have the opposite effect, with successive positive offsets being added. When a rising voltage is fed via this particular setup to a VCO, rising "bubbles" will result. There is also an offset adjustment to adjust the initial value to which the modulo will be applied. An optional switch will allow the number of modulo cycles to be limited between 8 and 1. Of course that is not the only way this module can be used. It can also be used as an audio frequency wave multiplier. A triangle, sine or sawtooth waveform at audio frequencies can be modified to produce some pleasant reedy type sounds. As the inputs can be controlled by CVs, these timbres can of course be swept. visit http://www.cgs.synth.net for construction guide on this module ,circuit analysis ,bill of materials ,pcb's Edit - Page last modified on 2013-02-24 14:54 [UTC-7] - 2996 views