Parts
You can use either metal shaft 9mm pots or trimmers for the Rate and Depth control. Pots obviously
give you the ability to dial in all kinds of different modulation. But, if you one just one type of modula-
tion (say a slow, subtle modulation on longer delays) then trimmers allow you to just “set and forget”
without having to drill more holes in your enclosure.
9mm metal shaft potentiometers (100kC, 100kB):
http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-9mm-pc-mount/
Bourns 3362p (100k):
https://www.mouser.com/ProductDetail/Bourns/3362P-1-104LF?qs=sGAEpiMZZMvygUB3GLcD7l-
39JMs%2F%2F%2FLOs09gVZSzi2c%3D
https://www.taydaelectronics.com/potentiometer-variable-resistors/cermet-potentiome-
ters/3362p/100k-ohm-trimmer-potentiometer-cermet-1-turn-3362p.html
9203 photocell:
http://smallbear-electronics.mybigcommerce.com/photocells-cds-5mm-diameter/
You can also use some of the cheap Tayda ones:
https://www.taydaelectronics.com/resistors/photoresistors/photo-conductive-cell-resis-
tor-ldr-650nm-radial-ke-10720.html
SPDT Mini (On/On):
http://smallbear-electronics.mybigcommerce.com/spdt-on-on-mountain-10tc410/
SPDT regular size (On/On):
http://smallbear-electronics.mybigcommerce.com/spdt-on-on-short-lever/
Low -profile Electrolytic cap (22uF):
http://smallbear-electronics.mybigcommerce.com/electrolytic-radial-low-profile-16v-1-f-100-f/
• For the LEDs, use 3mm, red diffused for both D1 and LED parts.
• You can use a TL072 instead of the 062 for the IC.
When powered, pin8 of the TL062 should read about 9v, pin4 0v and all other pins will have varying
voltage.
Bend the legs on your photocell and D1 so that the top of the LED points toward the face of the pho-
tocell. You can enclose the LED and Photocell in some heat shrink or tape, but it’s not absolutely
required. However, when testing it outside the enclosure put a towel or something over it to block your
room lights from interacting with the photocell. This will let you know how well the modulation will work
once in the enclosure.
Voltages
Notes
Summary of Contents for AQB_MOD 2019
Page 6: ...Schematic ...
