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
