CubuSynth ADSR User manual
CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
ADSR
Envelope Generator with Looping Mode,
Time and Level control
Build Guide
PCB V2.1 Aug 2021
Written and Illustrated by Ruben S onar
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
Introduction
The CubuSynth ADSR Module is a VC loo ing envelo e generator based on the Electric Druid EnvGen8, with controls for
the Attack, Decay, Sustain and Release stages, for overall Time of the envelo e and CV in uts for Time and Level.
The EnvGen8 chi was written/designed by Tom Wiltshire aka "Electric Druid". For more information visit:
htt s://electricdruid.net/ roduct/envgen8/
1ATTACK (1ms - 10s)
Sets the time, the Envelo e takes to reach full level from the moment a gate is detected (Key is ressed)
DECAY (1ms - 10s)
Sets the time, after the envelo e hits full level, to fade to the level set by the SUSTAIN Knob.
3SUSTAIN (0% – 100%)
Sets the Volume to stay after the decay, while the GATE in ut is high.
4RELEASE (1ms - 10s)
Sets the time for the fade out on falling edge of the GATE in ut (after the Key is released)
5MODE switch
Select between ex onential and linear curves.
6PUNCH switch
Adds extra thum to very short ercussive envelo es
7LOOPING MODE switch
Allows selection between three different modes of o eration. "Gated" mode acts as a normal envelo e.
"Gated Loo " will trigger the ATTACK stage when the GATE goes high, then continue loo ing whilst the GATE
remains high, and will RELEASE to zero when the GATE goes low. The LFO Loo ing mode loo s continuously
and ignores in ut from the GATE.
8TIME (x1 – x100)
Overall Time control which shortens the length of the entire envelo e.
9TIME CV Attenuator
Attenuates incoming CV for Time modulation. Higher voltages will
shorten the length of the envelo e.
10 TRIG In ut
Envelo e goes to ATTACK stage on rising edge of Pulse while Gate can
still be on. Re-trigger for the envelo e, used for Poly honic atches.
11 GATE In ut
Envelo e goes to RELEASE stage on the falling edge.
1 Level CV In ut
Control the overall Volume of the envelo e. Can be used for velocity
control. If nothing is lugged in, the Volume stays on max.
13 OUT
CV-out ut of the envelo e (0 to +5V)
14 LED
Indicates the out ut voltage.
15 TIME CV
CV In ut for Time modulation. Higher voltages will shorten the length
of the envelo e.
16 INV. OUT
Inverted voltage of the out ut CV (0 to -5V)
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
BUILD GUIDE
STEP 1
1N4148 x6
As always start with the smallest com onents. In this case it's the
1N4148 Diodes. Make sure the black line on the diode is lined u with
the white stri e on the PCB.
Bend the solder legs outwards, so it doesn't fall when turning around
the board. (same for STEP 2-10)
STEP 2
1N400X* x2
identify the 1N400X* diodes and ut them in lace. Again orientation is
Im ortant. These are the reverse voltage rotection diodes. The white
line on the diode has to line u with the stri e on the PCB silkscreen.
Turn board around and solder everything in lace.
*can be any from 1N4001 to 4007 or 1N5819 (marked as 1N4001 on the
PCB)
STEP 3
330R resistors x2
When all diodes are soldered, look for the 330ohm resistors and ut
them in lace.
Orientation on all resistors doesn't matter.
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
STEP 4
1k resistors x4
Find the 1k resistors and ut them in lace.
STEP 5
2k resistor x1
Identify the 2k resistor in the bag and ut it in in lace.
STEP 6
4.7k resistor x2
Identify the 4.7k resistors and ut them in in lace.
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
STEP 7
10k resistors x6
Identify the 10k resistors and ut them in in lace.
STEP 8
47k resistor x1
Identify the 47k resistor and ut it in in lace.
STEP 9
100k resistor x11
Identify the 100k resistors and ut them in in lace.
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
STEP 10
200k resistor x1
Identify the 200k resistor and ut it in in lace.
Make sure all resistor legs are bent slightly outwards so they don't fall
out. Turn the board around and solder all resistors.
STEP 11
IC sockets
Look for the di -8 and di -14 sockets. Put the 14 in sockets in lace,
with the notch looking to the to of the PCB.
Oriantation is im ortant to know how to lace the ICs later!
You can bend 2 ins of each socket inwards, so they stay in lace when
turning the board around.
STEP 12
47 f ceramic ca acitors x2
Find the 47 f ca acitors marked "47". The orientation doesn't matter.
Put them in lace and bend the solder legs outwards, so it doesn't fall
when turning around the board.
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
STEP 13
100nf ceramic ca acitors x11
Identify all 100nf ca acitors marked "104". Orientation doesn't matter.
Put them in lace and bend the solder legs outwards, so it doesn't fall
when turning around the board.
Solder all ceramic ca acitors in lace.
STEP 14
BC547 transistors x3
Take the three BC547 transistors and bend its legs slightly outwards, so
they fit in the holes. Make sure the Orientation of the transistor
matches the marking on the PCB. The flat side of the transistor has to
line u with the straight line on the PCB.
Turn the board around and solder the transistors.
STEP 15
16 in Power connector
Now take the shrouded 16 in connector and ut it in lace on the
back of the PCB. Make sure the cut-out matches the marking in the
silkscreen.
You can tem orarely ta e the Power header to the PCB so it doesn't
fall out while soldering
Turn the board around and solder the ower ins.
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
STEP 16
10uf electrolytic ca acitor x1
Look for the 10uf ca acitor and ut it in lace on the back of the board.
Orientation is im ortant. The white line on the ca acitor must be facing
downwards. Shorter leg goes in the squared hole.
STEP 17
47uf electrolytic ca acitor x2
Look for the 47uf ca acitors and ut them in lace. Again orientation is
im ortant. The white line on the ca acitor is facing downwards.
Shorter leg goes in the squared hole.
Turn the board around and solder ca acitors.
STEP 18 (Controls)
B10k otentiometer x5; B100k otentiometer x1;
ON-ON switch (SPDT) x2; ON-OFF-ON switch (SPDT) x1;
PJ-301M Jack (Thonkiconn) x6; LED x1
After all revios ste s are done and all solder legs are cutted off, take
the Potentiometers, jacks, switches and the LED and ut them in lace
as marked on the PCB but don't solder yet.
If you have switches with solder lugs, a bit of ressure is needed to
make them fit in the holes.
The u er and lower jacks each share a hole for ground. For the LED
the orientation is im ortant. Contrary to the ca acitors, the longer leg
goes in the square hole, flat side of the LED facing down.
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CubuSynth ADSR - Build Guide PCB V2.1 Aug 2021
When everything is in lace, take the front anel and ut it on to , so all controls go into each
corres onding hole of the anel. Push the LED u , to line u to the front. Put all the nuts on the
Potentiometers, switches and Jacks and tighten with your hands. Then carefully fli the board
around and solder everything.
STEP 19 – Installing ICs and final check
Take off the front anel again and install the ICs. EnvGen8 chi on to , TL074 in the middle and
TL072 down. Make sure the orientation is correct, the notch has to match the silkscreen, facing
to the to of the PCB!
Check your soldering. If you see shorts or bad soldering, fix it u . Then check the ower ins for
shorts with your multimeter.
When everything looks fine, you can ut the front anel back again, tighten all the Nuts and ut
the knobs on the Potentiometer. For best results, turn all Potentiometers counter-clockwise and
ush on the knobs, so the marking oints towards the left end of the surrounding circle.
Congratulations, now you can ower u your module and have fun atching!
If you have trouble with your build, you can contact us at:
For better su ort, lease include ictures of your soldered board, front+back.
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