Circuitbenders Forum
Circuitbenders Forum => Circuitbending discussion => Effects Units => Topic started by: phantompowers on April 01, 2010, 11:37:27 PM
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I was inspired by the 'Stutter effect' pedal on the Beavis Audio research site -
http://www.beavisaudio.com/projects/StutterPedal/index.htm (http://www.beavisaudio.com/projects/StutterPedal/index.htm) and I came up with this idea.
If, instead of cutting out the audio every time you pressed the pedal, you had it cut in and out automatically, at a fast speed, you would create a crude tremolo effect. So, I made a 555 timer circuit to flash a couple of LED's, made one into a 'vactrol' and attached the LDR's legs to the audio live and ground output. It worked great, a very lo-fi noisy tremolo effect! I can adjust the speed, I added a depth control and a ramp wave effect by adding a capacitor to the LED in parallel.
Only thing is and I can't figure this out is it works great on my guitar, works great on my 555 tone generators but it doesn't do a damn thing on my keyboards!! This really confused me and I thought my 'pedal' was somehow faulty so I dismantled every bloody solder connection 'til there was nothing left but a mass of crocodile clips only to discover that there was nothing wrong all along!!!
What the funk?!!!
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Probably some grounding issue somewhere, it usually is when you can't work out why something works with a guitar but nothing else.
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How have you got the LDR wired? If it's just wired across the input and output, it will do bugger all to a high-impedance signal like a synth output. Wire it as a potential divider insteadl, that'll work much better.
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Cheers for your replies,
I wired the LDR stright to the output jack. One leg to ground, one leg to earth.
So,(I've just researched this), a potential divider will cut the signal out by decreasing the input voltage?