Peavey classic duel 212 scratchy popping noise

[bigj]

I just got a peavey duel 212 classic series tube amp that has a scratchy popping noise after warm up . I repaced the 6l6tubes visually inspected and did the tap method inside . I also pulled each tube with no effect . I used freeze mist in each component but found nothing . Any ideas . This is my first post , this is a great sight , thanks so much

[Twist]

Does the noise ever come back after the initial warm up? Did you replace the tubes with a different set?

[bigj]

re: peavey duel 212

Thanks for the response . After it warrms up it pretty much sticks around , sometimes worse than others . I did replace the 6l6's . I also had an extra set of pre-amp tubes that I tried out . Thanks

[Amp Kat]

I would think one of your pots is bad mainly a volume control. Does it still have the can cap in it ? Ooops gotta go Huirricane is about to put the power out but were fine otherwise.

[bigj]

It doesnt have the medal can caps in it . I visually checked the electrolytic caps with the leads on the ends for leakage but saw nothing . the only ones I couldnt check were the large caps in the power supply where the leads come out the bottom . maybe I should pull those . I also cleaned the pots . There's no symtom change if any of the pots are turned , even with the volume turned completely down . I plugged a signal soarce into the preamp side and the symtoms dissapear . Thanks

[Twist]

When you said you plugged into the pre amp side do you mean the pre amp out and power amp in jacks? I'll have to go dig up the schem for that one. It sounds like you have isolated the problem to one particular section. Also that noise can come from weak plate resistors on the pre amp tubes.

[bigj]

Sounds great , I really appeciate the help .

[Agus]

same shimptom

Guys, seem like I face same problem.
What is actualy the problem and how to solve it?

BR
Agus S