Date Region Description Price Seller
UK4 Variable Waveshape Operators for Linear FM SynthesisImplementing frequ...$626.62
EUGreat conditions and perfecty working Fast and tracked EU shipping +15€...€300,00uopiti
EUINCL. ALGO EXPANDER. Like new. ### technical condition Works flawles...€445,00StringEmil
SwitzerlandThe overall condition of this *Humble Audio Quad Operator* is *like new*...CHF320.00lualungck
USAHumble Audio Quad OperatorIn perfect condition, rarely used. One of the...$350.00
USAUsed in a non smoking studio. All the knobs work. ![Humble Audio Quad ...$335.00