I thought this might be a good place for a quick amp question. Thanks in advance for any replies. I recently purchased a SANO 500 amplifier. When I bought the amp it didn't power up and had a blown fuse (which was way too big). I replaced the filtering capacitors in the power section and any electrolytics. It powers up now and is fairly quiet except for some noise in the reverb circuit. The problem I am having is that when I turn the amp on there is a loud crackling sound until it powers up. It does the same thing when I turn it off. I replaced a cap can on my Princeton reverb and that does the same thing. Is it possible that it is a poor ground on the cap can? The cap cans are hard to solder. Any ideas? Again thank in advance.