Twofold question: First, I have a preamp & Crest power amp driving a Hartke 4x10XL cabinet. The amp is 250w/side, 500w bridged mono. The cabinet is rated at 400w. It is a stereo amp, but since I only have one cabinet, am I better off using only one side of the amp, or using the bridged output? (I have been using the bridged output) Second, the amp has only an on/off switch on the front panel, with small pots on the back panel to adjust the output. Should I max the output on the amp and use my preamp gain to adjust volume, or should I back off the output of the amp and adjust the preamp gain higher? It has been working fine up to now, I just dont want to blow the speakers due to long term damage. Thanks!