My 5152 makes a loud swooshing statiky noise for a few seconds whenever I turn it off and on standby. After it goes away the amp sounds phenomenal. I found a thread with the same problem and the guy said in his particular case it was a Bad Cathode Bypass Cap on V1 physically v2. He replaced it with a nichicon 2.2uf/50 cap and it fixed it. Is this a pro techs job or fairly easy diy? I can solder but my experience is limited with amps.