Bipolar Voltage Converter

This will be a useful little circuit for anyone wanting voltage doubling and negative voltage from a single charge pump.  I've done this with a particular layout in mind, but I think it may come in handy for a few effects that require +/- supplies, which can now be accommodated with a small daughterboard.

I don't know if this will work with our more commonly used ICL7660S although the pinout does appear to be the same.  The schematic called for LT1054 which are more expensive, but I only paid about £5 for 5 on eBay a while ago and so they can still be had for a reasonable price without being fleeced too much.  If you do want to try the ICL7660S then it may be worth omitting the cut between pins 1 and 8 to enable the frequency boost so you don't get noise.  The LT1054's oscillator typically runs at 25kHz.

Using the 1N5817 diodes shown should give you around +/-17V, but if an effect calls for +/-15V then you could always opt for using 1N4001 diodes instead.  The extra voltage drop will get you closer to 15V.