Vactrol VCAs and CV attenuators - DIY Modular in a Week 2.1

Day 2: VCAs
Part 1: Vactrols
Difficulty: Easy
Price: ~3-4$
MiaW playlist: https://www.youtube.com/playlist?list=PLyE56WXw0_5Q5QGMEXWmskuhojKyRdA3T

Welcome to day 2, where we start to look at VCA (Voltage Controlled Amplifiers although as Das Kässpätzle pointed out in the comments these are not Amplifiers, as they do not Amplify the signal, but more voltage controlled gates...). These are the "gates" of the signal, and depending on the voltage input it opens it up more or less, and later on using Envelope Generators like AD, AR, or ADSR we can make really soft sounds. For now we use square waves from the slow oscillators on the oscillator bank to control the gate, which results in very hard on/off sounds. That said, the Vactrol in its setup is quite a gentle vca, which has a nice decay in the closing of the gate as the LDR is slow in its resistance change.
I did forget to show the Panel design in Inkscape but there is a link below to that one aswell...

Links to schematics, parts and other relevant stuff:

Link to the Schematics:
https://www.dropbox.com/s/o6oiyanco8lzmvt/Schematic_Vactrol.pdf?dl=0

Link to the fronpanel design svg file:
https://www.dropbox.com/s/ndr1vandajrlyuu/2.1%20Vactrol%20VCA_4hp.svg?dl=0

Link to the component spreadsheet:
https://www.dropbox.com/s/fn9gbn0vo0fteab/MIAW%20Component%20list.xlsx?dl=0

Link to ALL the files for all the episodes as they become available:
https://www.dropbox.com/sh/ynbxdv9nn6z0k47/AABt6dAvez4M-Mz-R9saO9Tka?dl=0

Ebay link to buy LDRs:
https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575103922&campid=5338181421&mpre=https%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_from%3DR40%26_trksid%3Dm570.l1313%26_nkw%3Dldr%26_sacat%3D0%26LH_TitleDesc%3D0%26_osacat%3D0%26_odkw%3Dldr%2B10x%26LH_TitleDesc%3D0

Link to 100 3.5mm 1meter cables for 45$ on aliexpress. This is the most cables for least price I found:
http://s.click.aliexpress.com/e/ctOgXegY

Link to oscilloscope:
https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575103922&campid=5338181421&mpre=https%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_from%3DR40%26_trksid%3Dm570.l1313%26_nkw%3DDSO138%26_sacat%3D0

PATREON LINK If you wish to support my work more than just a thumbs up :)
https://www.patreon.com/SourceryOne

Видео Vactrol VCAs and CV attenuators - DIY Modular in a Week 2.1 канала Kristian Blåsol