I just received an Ampeg SVT-8 bass head yesterday, and when I power it up, after about 1 second, I hear a "Zap" sound through the speaker, and then it's fine. I use the same Monster Pro 1000 speakon cable for a Boogie Titan V12, and that's fine. I also tired a Speakon to 1/4", and it still made the same Zap. I'm also using the same Monster Pro 2500 power conditioner for all my amps with no problems. Just this new Ampeg head has a Zap on powerup. Is it possible that the previous owner had turned on the amp a few times without any speaker load plugged in, and that's what's causing this? Any ideas, or should I just bring it in for service? Thanks.