Erica Synths POLIVOKS VCF Parts list manual

GUIDE TO ASSEMBLY OF ERICA SYNTHS POLIVOKS VCF
If you are reading this, most probably, you are about to build Erica
Synths DIY Polivoks VCF. This module is 30mm deep, skiff friendly,
has solid mechanical construction and doesn’t require wiring.
Polivoks VCF is famous for its’ crazy resonance sweeps and deep,
bassy sound which makes it ideal for acid basslines. We believe,
this is one of most is one of most authentic sounding famous
Russian synth Polivoks VCF emulations available. The original
Russian ICs K140UD12 are used in the sound circuit. We did several
updates to adapt the VCF for contemporary modular synth
demands. Independently buffered inputs, extended Cutoff knob
range, eliminated clicks, when switching filter modes, and output
stage added to eliminate signal inversion.
The DIY Polivoks VCF kit comes in three versions:
1) PCB + 2xK140UD12 ICs,
2) PCB + 2xK140UD12 ICs + panel,
3) Full kit.
FEATURES:
•Switchable BP/LP modes
•Inputs/outputs are protected against over-voltage
•Protection on reversed power supply
•Skiff friendly design
SPECIFICATIONS:
•Input level up to 20Vptp
•CV input level -10V - +10V
•Filter modes BP(6dB/oct)/LP(12dB/oct)
•Module width 10HP
•Module depth 30mm
•Power consumption 11mA@+12V, 11mA@-12V
1
34
2
5
6
1
2
3
4
5
6
Big knob makes a difference! This is a filter
cutoff frequency control.
Adjust input signal level with this knob!
Polivoks VCF is famous for its crazy resonance
sweeps and self oscillation. Use this knob with
responsibly!
.
Adjust cutoff CV levels!
These are inputs and outputs –no mystery here.
Switch between lowpass and bandpass filter
modes!

Take precautions with regard to electrostatic discharge (ESD) safety. Handling components should be done in
electrostatically safe environment. Use personal and workplace grounding. Any discharge (even a minor one) from
body to a component may permanently damage it.
Our PCBs have silkscreened both component values and designators nevertheless we highly recommend you to print
out files with component placement before you start assembly of the module. And, please, at least take a look on this
manual!
Some components are marked as NU (not used) –leave those unpopulated! Some components are market as OPTION
(those are for optional modifications) –leave those unpopulated for now.
ASSEMBLY
1In order to save space and make the module more compact, most or resistors are installed vertically (you also may want
to replace them with 0805 smt resistors). See the close-up for correct installation! Pay attention on resistor placement –
don’t accidentally install them in the testpoint hole! Also solder diodes! Pay attention on orientation of diodes!
2
GUIDE TO ASSEMBLY OF ERICA SYNTHS POLIVOKS VCF
Solder IC
sockets!
3Solder capacitors, ferrite beads and resettable fuses
(you may replace them with wire jumpers on your own
risk)!
4Solder electrolytic capacitors (pay attention on
orientation), a transistor, trimpot and opamps in
metallic cans –align the key to the silkscreen!
This is negative
lug of the
electrolytic
capacitor

GUIDE TO ASSEMBLY OF ERICA SYNTHS POLIVOKS VCF
5Solder PSU connector! 6Turn the PCB around and solder
potentiometers, jacks and mode switch!
7Install the front panel, use jack and potentiometer nuts
to tighten it. Install potentiometer knobs! 8Congratulations! You have completed the assembly of Erica Synths DIY Polivoks VCF. If
assembly is done correctly, the module
should work straight away.
Calibration is easy –turn Cutoff knob full
counter clockwise and adjust a trimpot on
the PCB so that the VCF is fully closed.
ENJOY!