Available as an assembled Module and as a DIY project.
This Module is currently available.
Wave Multiplier
The ES17 provides a sweep of the odd harmonics (1, 3, 5, 7, 9, 11,and 13th) when a sine wave is applied to its input and the knob is turned up or a control voltage is swept from low to high. This effect is similar to overblowing a wind pipe closed at one end, and thus the module can be used to produce the sounds of various wind instruments . A second input is included to allow two signals to be mixed before processing, a technique that has been found to be very usable.
This module can be used to explore timbral areas beyond the range of ring modulation because there are more varied harmonics than the sum and difference tones.
https://www.elby-designs.com/webtek/euro-serge/es17-vc-multiplier2/es17.htm
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These merchants probably sell this module. Huh?