I'd help you out if I knew more about bridging, but while I was testing my amp I was just cheating to bridge it. As you probably know, to bridge 2 channels of an amp, you need the signal to one channel inverted and the other channel regular phase, and connect your speaker across the output of both channels.
For since my amp was 4 channel, 2 channels were standard and 2 inverted. to get the signals I used my laptop playing music in Winamp. I ran a DSP plugin that allows you to invert one channel, so my left channel was standard and right inverted, that's how I 'bridged' my amp for testing, and then connected each speaker to a left and a right channel. Next I will have to find out how to invert the signal internally in the amp... Upon searching stk4050v in the forum I'm pretty sure one of the few topic results had details on an easy way to bridge the modules using the output of one stk4050 to feed the other channel.
If you find anything on an easy preamp that provides a regular and inverted output, let me know.
