Some build notes for the Nonlinear circuits VC ADSR.
This is part 1
This uses the classic Jacky/Kirschman 555 ADSR circuit from 1980
This is a super simple circuit that uses two chip types (a 555 timer or a CMOS 4016 & an op-amp) and some diodes. Jacky's circuit uses the 555, while Kirschman uses a 4016.
Andrew has replaced the Attack-Decay-Release pots with DIY vactrols.
This NLC module uses a 555 which controls the sequencing while the diodes switch the currents.
Its a envelope generator of course.
All in Eurorack format. The module is 10HP
Links:
+ BOM
+ WIKI
The module is thus a combination of a few old circuits.... the 555 ADSR circuit
with some LDRs & LEDs used instead of pots.
It uses black boxes made out of headers to keep the LDR/LEDs isolated from extraneous light.
Essentially these are DIY vactrols.
IC's on first
Five 072 op-amps & a 555 timer chip
BC847
LL4148
resistors, caps
trimmer
Schottky, power
rectifier??
I'm using a 10R
resistor for power protection.
I'm using 2.2k resistors for the Led Resistor (RL).
For the LDRs
Andrew used GL5516
I'm using GL5549
(only because I have a heap of them).
As with all these builds, experimentation is best.
Would be great to do some variations of this module using different coloured LEDs and
LDRs
I'm using green LEDs for the vactrols
and a blue LED for the panel just to be different.
Andrews recommendations are red or green
for the vactrol LEDs
Make the Box next
using headers. The LEDs and LDRs will go here.
These are always a bit tricky
Cut the male & female headers to the correct size 1st
Then solder ...
I usually start with the sides first, then the central dividers next.
The final box needs to be light proof.
To be continued...
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You can find more NLC builds here.
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