"singing" valves in my AD200

[macahan]

I have an AD200B manufactured in 2001. The original tubes are still in and when bought it had only been played about 10 times..

anyway.. the valves are singing.. apart from the humming that's also there and there are som cracking noises like the noises fron a broken cord...

the singing in the valves sounds almost like a leslie rotating.

cracking noises can't be good.. at first i thought my speaker had died but the noises were still there when switched to an orange 4x12.

however the noises dissapear when the amp is pushed hard by a strong in-signal and then put on standby... and switched back on after a while.. but the cracking noises are still there..

everytime the amp is moved some distance theese sounds appear.
but when left in the same place end played for two days straight the sounds are gone..

what the (/#"&&/!! is wrong with it?
is it the valves? is it an electric problem???


my ad200 sounds amazing..

[bclaire]

crackling noises often are the guitar cord- have you ruled that out with a good cord?

[macahan]

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
crackling noises often are the guitar cord- have you ruled that out with a good cord?


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the guitarchord itself is ok, the cable between the speaker and the amp i'm not so sure about.. but the singing valves?? i mean.. the crackling noises aren't like the crackling noises produced by a guitarchord... it's something else..

my ad200 sounds amazing..