Vpol Oscillator / Filter

The vdPol Oscillator and Filter is a specific rich sounding analogue device that generates surprising signals – especially when you connect more of them together in a chain. In the setup shown below, the circuit has 4 outputs, and 4 inputs. Since the filter is constructed around a series of integrators connected in a feedback loop (in combination with 4- quadrant multpliers) there are 4 locations within that loop that create different wave-shapes – output 1,2,3 and 4

To change the frequency or the Mu (weight) there are two control voltage inputs. It has 2 audio inputs.

TheĀ  vdPol filter (see also the blog post) printed circuit board (pcb)

(all components indicated with * are optional)

R1, R9, R14*, R20 47k
R2, R6, R7, R11, R22, R33 33k
R3, R8, R23, R32 560E
R4, R5, R10, R13,
R15*, R17*, R21*, R24*
R26, R30, 100k
R16, R18, R27, R29, R31, R34 10k
R19 15k
R25 68E
R12, R28 100k trimpot


C1, C5, C6, C11, C12,
C15*, C16, C17*, C20
C2, C7, C18, C21, 680pF
C3, C4 10uF
C8, C9, C10 10nF
C13, C22 33pF
C14, C19 100nF**

** These capacitors are part of the integrators. This value determines its (frequency) behaviour.


D1 BAT19
IC1 * 7812 (voltage regulator)
IC2 * 7912 (voltage regulator)
IC3 TL074P (socket)
IC4 TL074P (socket)
IC5 AD633 (socket)
IC6 AD633 (socket)
IC7 MC4558 / TL072 (socket)
IC8 MC4558 / TL072 (socket)
U1 V2164D (socket)

* The voltage-regulars are optional and can be left out when you make the circuit ‘eurorack-compatible’.


JP1, JP2, JP3, JP4, JP7, JP9 0E jumper Routing of CV
JP6* (not connected in normal mode) 0E jumper Mode conn V2164
JP5*, JP8* 0E jumper
SV1, SV2, SV3, SV4, SV5, SV11, SV16 3-pin male header Conn. pins for ext pot
SV6*, SV7*, SV10*, SV12* 3-pin male header
Sv13*, SV14*, SV15* 3-pin
SV8*, SV9* 12-pin header
SV17 10-pin header Eurorack power conn
X1 32-pin MAC32L For analogue studio rack only