2. amps-preamps
  3. 136120-97064

Pass labs X250.5 cracking noise

Hi all, recently bought a used X250.5 from a dealer on audiogon. Really happy with the SQ. The amp makes a crackling noise after powering down. Its a few cracks/pops - very intermittent and then it subsides. Spoke with Pass engineer and he assured me that the noise was coming from thermal contraction of heat sinks etc after normal operation. This weekend I noticed that the amp made cracking noise during warm up too. Again this is one or two and then after the amp warms up - i dont hear any more pops. Or i guess the sound from speaker masks it perhaps? I did pause music and noticed the amp for about 30 minutes and no cracking/popping noise during that period. Anything I should be worried about? I'll call Pass again this week - but wanted to see if there were any thoughts?
pistha

Showing 1 response by jsd52756

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jsd52756
454 posts
 
From my Krell owners manual: "When powering on any system, turn on amplifiers last. Turn off amplifiers first. "
I made the mistake of turning off the pre-amp first once & the sound that came out of the speakers was not pretty.  Scared the heck outa me. 
Perhaps that's the issue.  Good luck, John
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