Refer Silicon Chip July 2008
There are no modifications required on the amplifier and the signal processing is done by the kit before the signals are fed to the stereo amp. The kit is perfect for say, using a stereo amplifier as an occasional PA amplifier for social functions or using and old amplifier to drive a sub-woofer in a home theatre system. It sounds like magic, but is just a clever adaptation of basic electronic principles. Kit supplied with silk screened PCB and all specified components. Requires balanced (+/-) power supply from +/- 15 to +/- 60VDC.