Latest video giving a brief overview of a simple but very useful single-rail to split-rail DC power supply design.
Small form-factor. Generates +5V, +12V, and -12V rails from something like a standard 9V battery.
I designed a low-noise, low-distortion headphone amplifier using only NE5532 op-amps… 44 of them in total!
Take a look at how I did it here: http://philsal.co.uk/projects/misc-electronics/ne-xt-headphone-amplifier