Pass labs poweramps

All my Amps are Pass Labs X250 X260.5 and anX5 I would call the sound more like a single clink sound like water in an old radiator when it warms up. All this equipment I have purchased second hand and any time I have a question I have called Kent English or emailed him. He has always treated me like I just purchased the most expensive Amplifier they make Best service I ever had in or out of warranty. They STAND behind what they sell

Ditto on my X250.5 - definitely notice metal sorta clicking noise after powering down. I called Pass and they explained it was the thermal contraction in the heat sink causing the noise and that it was completely normal. This past weekend - i noticed clicking during warm up and got a bit worried. But glad to see I am not alone in noticing clicking during warm up. So far - it has not affected the SQ - its a solid performer otherwise!

Yes Folks...all that sound is ..just the amps cooling down..expansion of cooling fins returning to room temp.... NORMAL ALWAYS..no worry needed what so ever....!!!!  Rock On..!!!!

I've had an F5 for about a year. I've never heard any noise when my amp is warming up,or cooling down. Maybe I should get my hearing checked. :-)

Same here with my 250.8 clinking sound about 20 minutes after being turned on. Haven't really stuck around after shut down to see if the same happens on cool down.