Pianos & Keyboards
Doepfer A-101-6
Doepfer A-101-6, Six Stage Opto FET VCF, New filter module in which so-called opto FETs are used to control the filter frequency, Dimensions (W x D): 40.3 mm (8 HP) x 65 mm, Power requirement: 40 mA
https://www.bizrate.co.uk/keyboards_midicontrollers/doepfer-a-101-6-oid6492463589.html