hey guys,
well i built my 3 legged dog a couple weeks ago, and ive been tweaking it around a bit to discover that it's much more of a distortion booster than a self-contained fuzz box. it's a very low noise circuit which is great except i have a few problems with grounding.
when the pedal is switched on and there is no signal it goes quite droney with hum - especially noticeable with high gain settings on the amp - though i've discovered that when i put my bare foot on the switch or anywhere else on the box the hum stops and it's perfectly noise free.
and the other problem is that when the effect is bypassed there is a very high pitched tone that doesnt go away whether playing or not and it get's especially piercing and irritating at band levels - to the point where i had to turn it on the whole time, or take it out of the path completely.
the thing is in a small alluminium box and it's not especially big or thick, so maybe that's the problem, but any comments or suggestions are very welcome:)
thanks guys
trent
Check your wiring. I think you have a grounding problem, expecially since when you touch the box the hum goes away. The high-pitched squeal is the circuit oscillating. Try turning tha gain down a bit.
Try using the True Bypass with Circuit Input Grounding (http://www.generalguitargadgets.com/v2/index.php?option=html&file=instructions/switching_all.htm&Itemid=51&op=page&SubMenu=) wiring to cure the oscillation occuring when bypassed.
Also, how are you powering the circuit? A low battery can cause oscillation and other instability with the 4049.
Oh hell it's a 4049? My impression of those is that they eat batteries. Wallwarts! :D
Quote from: B TremblayTry using the True Bypass with Circuit Input Grounding (http://www.generalguitargadgets.com/v2/index.php?option=html&file=instructions/switching_all.htm&Itemid=51&op=page&SubMenu=) wiring to cure the oscillation occuring when bypassed.
Also, how are you powering the circuit? A low battery can cause oscillation and other instability with the 4049.
Both things happened to me in the high gain channel of my Double D. I did exactly what B says (input grounded and used a wallwart) to correct it.