Strange Noise on Volume Change...

Hi All -

Been browsing these forums for quite some time, finally bit the bullet and registered!

I just received a new (to me) DC-2 Studio Caliber amp. So far I love everything about it; it's surprisingly similar to my F-50 which I adore. Only problem is that when I quickly turn the volume down on my guitar, the amp makes a loud "click" noise like the chord was unplugged. It's not my guitar; I've tried it on a handful of other amps without getting the noise. If I slowly turn down I don't get the noise either.

Anyone ever experience this before? It sounds like a strange issue to have...

Thanks!

test another set of amp tubes, it looks like microphonics feedback

it comes when you roll your volumen of your guitar or your amp? i have a dc-2 and i had a similar noise when turning the output level , and when i sprayed contact cleaner/lub it went out.
hope this helps