I like the overall design of all these. Very strong, masculine and the name ties into the logo! #6 is nice maybe try a few different colors for electric like gold or different background. I also really like seeing since 1982.
in #4's Amp could you add the color of #6's Amp and add the since 1982 into it. Also make The A in amp look a little more like its an A I like the bolt but maybe try a few different ones? Then try maybe one with a gold color amp? I don't know for sure what I like but just throwing out some suggestions.
* Make the A in Amp more like an A if possible I want people to know for sure its an A#34 * could you make the letters a little thicker and the bolt of lighting? #34 * maybe even go through the P or something with the bolt of lighting #34 * or add a little more design to the letters? #34
if you made the letters thicker in #33 and one solid color between red and ruby red and changed the A to look more like and A and not a 4 I would have been very interested in this logo....