Fender Bass Amp Blues

[Orangedrink]

I have a little Fender Rumble 25 bass amp that I use to practice on at home. It is great for the first five minutes and then a fuzz sounds starts on the low end tones. Gradually it moves to the higher sounding tones until everything is a fuzzy sound and then the volume drops almost completely out. Turn off the amp and let it cool and it starts all over again. No one in my circle of friends seems to know what this is...I need a larger circle of friends.

Has anyone ever had this problem?

[lowell]

w/o seeing schematic, wild guess is that a component is overheating and melting the solder on that joint... causing those symptoms.

[Enzo]

Ball up your fist and whack the top of the amp when it does it next time. Does this have any effect? If so, there is a loose connection somewhere.

Also, take a spare cord or an unwired plug, and quickly plug in and out of each jack on the thing a couple times. Does this either restore the sound or does it trigger the problem? If either way happens, the jacks need service - either their contacts need dressing or their solder does.

ANd I would be looking at the main filter caps, is their solder cracked? Is one of hte caps drying out?