A modified Emerson Custom Paramount Overdrive with an internal 9V to 18V charge pump, a high/low gain switch that switches the transistor used as the amplifier either a 2N5088 (Low gain) or a MPSA13 (High gain). It also features an additional diode clipping stage via a 3-way switch: LED-None-Germanium.
This effect can vary from a near clean boost, overdrive to heavy distortion and works well with both bass and guitar. Video demo coming soon...

I used the following stripboard layouts:

Paramount Overdrive:
http://tagboardeffects.blogspot.co.uk/2014/02/emerson-custom-guitars-paramount.html
-I used a SIL socket to try various NPN transistors before wiring the gain switch.

Voltage Doubler Charge Pump:
http://tagboardeffects.blogspot.co.uk/2013/02/ne555-voltage-doubler.html