If you`re an effects builder or repairer, you know by now that it`s a good idea to protect the circuitry in the effect from the consequences of a reversed battery. While many older effects can withstand a momentary reversal, some more modern components can be damaged if you accidentally touch the battery contacts the wrong way during replacement. Sometimes this is subtle damage.
For instance, everyone pretty much knows that CMOS and some opamps can be killed by reversing their power supplies. This happens because the substrate of the entire chip is isolated from the circuit by a reversed bias diode diffusion. If the power supplie