Parts · Opto

GL5528

LDR (Photoresistor) 10-20 kΩ light 1 MΩ dark.3 circuits use this part. Listed as: Photo resistor GL5528.

Datasheet · archived copy from Senba; kept here as it was not found on the maker's own site

Substitutes same kind

Optocouplers and photoresistors of the same construction; the response speed and resistance range set how an effect sounds. The figures are read off each part's datasheet (this one's from page 2), typical where the sheet gives a typical value, otherwise the maximum. Closest first; the last column says what differs. A different part can change the sound, and a circuit may lean on one particular figure, so read the build document's notes before you swap.

This part

Part	On	Dark	Rise	Decay	Boards
GL5528	10k	1M	20 ms	30 ms	3

CdS cell, 10 to 20 kΩ at 10 lux, gamma 0.6.

Alternatives

Part	On	Dark	Rise	Decay	Boards	Differs
GL5537-1	20k	2M	20 ms	30 ms	2	CdS cell, 20 to 30 kΩ at 10 lux, gamma 0.6.
GL5516	5k	500k	30 ms	30 ms	9	CdS cell, 5 to 10 kΩ at 10 lux, gamma 0.5.
PDV-P9203	10k	5M	60 ms	25 ms	4	higher dark resistance. Bare CdS cell, 10-30 k at 10 lux and over 5 M dark; pair it with an LED in a light-tight sleeve for a homemade vactrol.
GL5549	100k	10M	20 ms	30 ms	1	higher on resistance; higher dark resistance. CdS cell, 100 to 200 kΩ at 10 lux, gamma 0.9.

Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
Tremshifter GL5516 OR GL5528 · TL072	Dead Astronaut Tremshifter	Other	Dead Astronaut FX	—	5	£15.00	59
DeadAstronaut Tremshifter Perfboard Verified 1458 · GL5516 OR GL5528 Dead Astronaut Tremshifter	Dead Astronaut Tremshifter	Tremolo	Effects Layouts (blog)	—	5	—	37
Plutonic Vibe BC547 · GL5528 · TL072 · TL074 EarthQuaker Devices The Depths · 1590B	EarthQuaker Devices The Depths	Vibrato / Chorus	HotKits	1590B	5	$6.50	30