Tuesday, April 17, 2018
CultureJam Shoot the Moon
Here's a great optical tremolo designed by CultureJam. Schematic can be found here. D1 is the external rate indicator and could be used as the on/off indicator as well. Just use part one pole of your 3PDT to break/connect one of the leads of D1. D2 and the LDR should be isolated together (heat shrink tubing works great). Tayda LDRs and either orange or red LEDs seem to work well in this circuit. A NSL32-SR3 optocoupler works well too.
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are the two 220k resistors at the start of the LFO not redundant? You could just connect it to Vr from the power section (the two 100k resistors) or am I wrong?
ReplyDeleteYou're not wrong, but doing so would most likely introduce tick from the LFO into the audio signal. I can't think of an IC-based LFO I've seen that doesn't do this.
DeleteVerified.
ReplyDeleteThanks Skeet!
Deletegood morning everyone, I'm new.
ReplyDeleteI have a problem with this project: it works fine for a few minutes then starts to distort and then does not produce any more sound.
I tried to change all the capacitors and both the ICs. same result.
any suggestions?
thanks, Stefano.
sorry for the english i used the google translator.
Hello to all.
ReplyDeleteI solved with a delicate cleaning of the pcb. Probable some small short circuit.
Now my problem is gain. Simply too much. I have to keep the potentiometer at most at 8 o'clock.
It's normal?
Thanks, Stefano.
Just finished this build on the weekend. Everything functions as it should.
ReplyDeleteI did have some issues where the LFO was not functioning and the wave control had no effect. I thought the 4558 chip I was using was dead (I pulled it from an old Peavey amp) but it turns out I had a small solder bridge that I didn't see initially.
Just finished it, took 8 hours from etching the PCB to casing it. The Korg SV-1 has an onbeard tremolo, but it doesn't sound right to my ears. It's such a sweet little thing. It was one of those smooth builds. Unlike Valve Wizard's Engineer's Thumb . That circuit drove me nuts. It's still harassing me. I think I has to etch it again one of these days.
ReplyDeleteThank you for the time and love you put in these.
You're a legend
Cheers
Does someone know a replace for the 5817 diode?
ReplyDeleteYou can use something like a 1N4001, it'll just drop the voltage a tiny bit more than the 1N5817
DeleteHi! Does anyone have any specifications for the LDR and its attached LED? Also, any replacement ideas for the JRC4558 would be much appreciated.
ReplyDeleteI used the GL5528 and it worked with a red led, not sure if it will sound better or worse with a different LDR.
DeleteThank you. This works beautifully!
ReplyDeletesorry for a newbie question, if im going to use the pcb layout. it assumes that im only going to use the black one for etching? it was on my mind thinking that this is only a single sided pcb.
ReplyDeleteTIA
Yes, only single sided. For a scaled PDF of this layout go to the Transfer Image Library tab at the top of the page
Delete