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The square pad isn't always a positive indicator. It's typically just a way of designating a "special" pin, like pin 1 of an IC. On a diode, the convention I usually see is the square pad is the diode's cathode. It indicates the direction of forward current. That makes the lines on the PCB markings consistent with those on the devices themselves.

Edited to note that when looking at LED's, it isn't always consistent. The usage I see most has the square pad going to the anode of an LED which corresponds to the long leg of the device.

Thanks, Rob! That makes sense. I'll treat these boards as such.

Hey all, I'm working on a first build of a Bumblebee, and am building the Road Rage, to reverse the ground polarity. My understanding is that the - lead of a diode is the side with the line drawn on it, and the + pad of a pcb is the square one. However, as the Madbean pcbs are drawn with little rectangles to indicate the diodes, but with little lines next the square pad, making it look like the diode lead coming from the side with the line (the negative lead) should go to the square pad (the positive pad).

You can see in the stock Bumblebee image below, at the bottom of the board. D1 clearly has a line on the side leading to the positive pad.

You can also see it in the Road Rage stock image below that. D3 and D4 on teh far left show a sort of line on the + pad side.

I'm a bit stumped. Anyone able to clear this up for me? Thanks!

You'll need to use a battery or separate power supply. Alternately, you could add one of madbean's Road Rage boards to generate -9vdc from a standard 9vdc power supply that may be also supplying other pedals.

Thanks for replying! I'm still not clear on how I'm supposed to wire it up as a -9vdc? Is it the same as a +9vdc?

Hey all,

I'm building a Bumblebee, and as I'm not an electrician/engineer, some of the finer points of circuitry sometimes escape me. I've built a few pedals successfully, but they've all been in a paint by numbers fashion, with the standard negative ground, which I can find plenty of information on.

However, this is the first time I've done a positive ground effect, and I'm not sure how to wire up the pedal/power supply portion. The Bumblebee project sheet doesn't have a wiring diagram for this portion, and I can't find another easy one online somewhere. Am I supposed to just wire it in the same fashion as the standard pedal wiring, provided on the madbean site, http://www.madbeanpedals.com/tutorials/downloads/StandardWiring_MBP.pdf, and just be sure to use a positive ground supply, or a 9v battery? Or is there something different I'm supposed to do that's escaping me?