Another post revealing my electronics ignorance... I'm putting together a distortion pedal from a kit and I'm having trouble identifying which end of the diode is which. To my eyes both ends have stripes: one end is black and one end is white. I initially matched the black end with the stripe on the PCB and connected to the square terminal (positive?). However by the only electrical convention I know (gel electrophoresis in biochemistry) the black lead is the negative one. So I'm getting myself all sounds around. Could anybody help me out? I don't want to go too much further without verifying this is correct.
Diode with two stripes
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Cagey
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The dark band on the diode should mark the cathode (negative) side, and should be aligned with the lined end of the silkscreen. I'm not sure if a square pad means positive or negative; that would be a new one on me. But, oddly enough, the cathode/negative side is often where you'll see positive potentials show up, since the diode presents a high impedance to current flow from negative to positive, so any positive voltage drop will show up on the negative side. It's a little counter-intuitive, but there it is.
Cagey
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Pretty sure. I looked it up because his diodes have two bands, which I haven't seen before and is what prompted the question. Probably should have talked about the meter test, too, just to be sure.
If you put the leads of an ohmmeter across a diode one way, then the other, you'll see a very wide range of resistance - usually >10:1. When the meter is reading a low resistance, then the side of the diode the black lead is on is the cathode, and the red lead will be on the anode.
Speaking of fuzz boxes, back about 100 years ago me and a buddy of mine both had one of those old Univox fuzz pedals we wish we still had because now they're "vintage" and valuable...
Thing was, they sounded pretty awful outside of a few specialized applications, like playing "Satisfaction" by the Stones or driving all the neighborhood dogs nuts. So, we managed to identify the clipping diodes and just cut the little rascals out. Turned the pedal into a wicked "power booster", which when used to beat on the input stage of our little NMV amps made them sound better. Sorta. In a way.
If you put the leads of an ohmmeter across a diode one way, then the other, you'll see a very wide range of resistance - usually >10:1. When the meter is reading a low resistance, then the side of the diode the black lead is on is the cathode, and the red lead will be on the anode.
Speaking of fuzz boxes, back about 100 years ago me and a buddy of mine both had one of those old Univox fuzz pedals we wish we still had because now they're "vintage" and valuable...
Thing was, they sounded pretty awful outside of a few specialized applications, like playing "Satisfaction" by the Stones or driving all the neighborhood dogs nuts. So, we managed to identify the clipping diodes and just cut the little rascals out. Turned the pedal into a wicked "power booster", which when used to beat on the input stage of our little NMV amps made them sound better. Sorta. In a way.
