I recently replaced a speaker for the first time in my Laney VC-50 2x12 combo. Not that it's important but, I replaced the 2 12" stock speakers (16 ohms each) with a single Hellatone 30 (8 ohms). To avoid de-soldering the original speakers I also connected the Hellatone with a new 1/4" jack to clip lead. Now when I turn on my amp I get a loud buzzing sound and little or no audible sound coming through the speaker. I have tried reversing the positive and negative terminals, and changing the output tubes with no luck. Now I am concerned that I have damaged something inside the chassis when I removed it. Can anyone suggest any other items I could check that could cause this? I am happy to take it to a tech if need be but they're expensive around here (and I'm broke) so I don't want to do so if its something simple.