Positive Ground pedal wiring?

[vacourtoy]

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?

[oldhousescott]

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.

[vacourtoy]

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?

[RobA]

It depends on how you have the -9V generated what you need to do. The board needs a voltage that is negative relative to ground going into the -9V. If you use the Road Rage without a battery in the circuit, then you can follow the diagram in the BumbleBee doc. If you do have a battery, then you just need to do the standard wiring trick with the ground and make sure you orient your battery connections the right way so that the voltage from the battery is negative relative to ground. If you have an isolated supply, then you can bring in the voltage from the supply with the power reversed. This is dangerous though, because someone might plug in a non-isolated supply and everything would go pop (at best) or burn up (at worst).

How do you plan on powering the pedal. Personally, I recommend using the Road Rage or something similar so that your power connection to pedal matches the standard effect setup.