Hi! I am not getting any oscillation, so I looked at the schematic. I think the top of R3 needs to be moved down one row, and C5 needs to be flipped. I’ve done this with no change, so I’ll keep at it. Thank you Anders! I know you are currently unable to comment, but if these changes seem correct/incorrect I will comment one way or the other.
Aha! One more thing. Drop speed 5 down one row. I now have a pulsing LED and audio, but no audible tremolo. I think I need to try a few different LDRs.
LED cathode (short leg) to bottom row (the pins near the diode symbol to the left of the word “vactrol”). The LDR are the pins all the way on the right. The orientation of the LDR doesn’t matter but it needs to face the LED and the two need to be covered in shrink-wrap.
I was just looking up the spec of the vactrol to make an ldr/LED combo, and the data sheet read an off resistance of 10m ohm, so would a GL5549 be the best option here?
Hey Ian, just saw your post now. I recall looking at the specs and trying a few LDRs, and I’m pretty sure I tried a GL5549 but went with GL5516 just by ear. I experimented by socketing both the LED and LDR, with a box to eliminate any light, and then, once I liked the combo, covered in heat shrink. Cheers!
Hi! I am not getting any oscillation, so I looked at the schematic. I think the top of R3 needs to be moved down one row, and C5 needs to be flipped. I’ve done this with no change, so I’ll keep at it. Thank you Anders! I know you are currently unable to comment, but if these changes seem correct/incorrect I will comment one way or the other.
ReplyDeleteAha! One more thing. Drop speed 5 down one row. I now have a pulsing LED and audio, but no audible tremolo. I think I need to try a few different LDRs.
ReplyDeleteBingo! GL5516 with a red LED = “lots o trem”! With the changes from my previous post, please tag!
ReplyDeleteThanks for commenting the LED and LDR you are using!
DeleteOne last thing: intensity 1 and 3 are reversed. Switch those, and the most intensity will be clockwise, as expected.
ReplyDeleteI woke up and the layout is now updated! Also: Bernard d’Uur’s page is full of fun stuff, so thanks for that as well!
ReplyDeleteIf im doing an LDR-LED combo how are they oriented on the board?
ReplyDeleteLED cathode (short leg) to bottom row (the pins near the diode symbol to the left of the word “vactrol”). The LDR are the pins all the way on the right. The orientation of the LDR doesn’t matter but it needs to face the LED and the two need to be covered in shrink-wrap.
DeleteThank you!
DeleteThis comment has been removed by the author.
DeleteThis comment has been removed by the author.
DeleteI was just looking up the spec of the vactrol to make an ldr/LED combo, and the data sheet read an off resistance of 10m ohm, so would a GL5549 be the best option here?
ReplyDeleteHey Ian, just saw your post now. I recall looking at the specs and trying a few LDRs, and I’m pretty sure I tried a GL5549 but went with GL5516 just by ear. I experimented by socketing both the LED and LDR, with a box to eliminate any light, and then, once I liked the combo, covered in heat shrink. Cheers!
ReplyDeleteBig no for me on this one. Lots of volume drop and weak controls.
ReplyDeleteShoot the moon is still the best tremolo here