~gilbert cell~
video demo - coming soon
i kept running into situations where i wanted an analog multiplier or VCA but the ICs are very expensive (up to $16.00 per device). therefore i decided to make a four-quadrant multiplier, or gilbert cell. I wanted to make it a modular device that would be easy to breadboard and also apply to the surface of a pcb.
fig. 1 - schematic (click for hi-res)
i have prototyped this unit and was able to make a frequency doubler, perform amplitude modulation, and get some pretty crazy ring modulator type effects. when i get together some funds i will likely panelize this project and send out for pcbs. i would like to use this module in place of the vactrols in my previous project to reduce its overal size and cost. once these boards are produced i will update this a bit more...
fig. 2 - pcb layout
fig. 3 - 3D pcb rendering, measures 16mm x 18.8mm