https://www.ehx.com/products/string9/
http://www.youtube.com/watch?v=lYrHAERhtVI
Beetronics Zzombee Filtremulator:
https://www.beetronicsfx.com/?_kx=F3GK6 ... GlO.U9TgcR
ANALOG MULTI EFFECT THAT DELIVERS FILTER, WAH, LFO, RANDOMIZED FILTER, TREMOLO, SWELLS, OVERDRIVE, FUZZ, LOW-OCTAVE AND THE NEVER BEEFORE HEARD HONEY PATENTED CROSS TREMOLO, A VERY UNIQUE KIND OF TREMOLO THAT PULSES BETWEEN THE FUNDAMENTAL AND A LOW OCTAVE
http://www.youtube.com/watch?v=gUK69fGork8