Erica Synths POLIVOKS-INSPIRED EG User manual

GUIDE TO ASSEMBLY OF ERICA SYNTHS POLIVOKS-INSPIRED EG
If you are reading this, most probably, you are about to build Erica
Synths DIY Polivoks-inspired Envelope generator. This module is
30mm deep, skiff friendly, has solid mechanical construction and
doesn’t require wiring. The core of the Envelope Generator is
borrowed from famous Russian synth Polivoks , but we significantly
updated schematics:
1) the original Polivoks has negative gate, therefore we made the
EG work form eurorack standard positive gates,
2) we adjusted envelope amplitude for eurorack modular
requirements,
3) we introduced inverted envelope output,
4) we updated looping feature (looping on gate on),
5) most importantly, we added Gate Delay feature –the module
outputs delayed gate signal after Attack stage. Chain up several (4-
5) Envelope Generators, each with delayed gate to create evolving
polyphonic synth-like pads!
The DIY Envelope kit comes in three versions:
1) PCB,
2) PCB + panel,
3) Full kit.
FEATURES:
•Full ADSR envelope
•Direct and inverted envelope outputs
•Gated and independent looping modes
•Gate delay (after Attack stage) output
•Skiff-friendly design
SPECIFICATIONS:
•Envelope amplitude 0…10V
•Attack time 0…3”
•Decay time 0…12”
•Sustain level 0…10V
•Release time 0…12”
•Panel width 8HP
•Module depth 30mm
•Power consumption 20mA@+12V, 10mA@-12V
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Adjust Attack time from 0 to 3”!
Adjust Decay time from 0 to 12”!
Adjust Sustain level from 0 to 10V!
Adjust Release time from 0 to 12”!
Select between normal ADSR and looping AR
mode! If patch cable is patched in Gate jack,
looping will occur only if the Gate signal is
present.
This is Gate Delay output. High Gate signal
appears here after the Attack stage.
This is Gate input.
This is inverted envelope output.
9This is main envelope output.
9

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!
GUIDE TO ASSEMBLY OF ERICA SYNTHS POLIVOKS-INSPIRED EG
3Solder transistors (do not mix NPN and PNP!) and
electrolytic capacitors! Mind polarity of the capacitors! 4Turn a PCB around and solder potentiometers,
jacks and a switch!
This is the negative lug of
the electrolytic capacitor!
2Solder IC socket, ceramic
capacitors, ferrite beads
and resettable fuses!
NB! We observed that when the EG
OUT is connected to certain VCAs, the
looping may stop. In order to make
looping more stable, replace R38 by
2,7k resistor!

5Solder PSU connector and install the IC!
5Install potentiometer knobs, and –whola! You have
completed Erica Synths DIY Envelope Generator!
5Insert LEDs, but do not solder them yet! Install front
panel and tighten it with potentiometer and jack
nuts. Now solder LEDs!
GUIDE TO ASSEMBLY OF ERICA SYNTHS POLIVOKS-INSPIRED EG
The module does not need calibration
and should work straight away.