Fender Problems

[bclick]

I have a Silverface 1971 Fender Super Six - same basic amp as a Twin in a bigger cab with six 10s. Had new tubes and some caps replaced about 2 years ago. 3 months ago was playing through it for 20 minutes when the volume faded out and a loud buzz began. Same in both channels. Same thing the next day.

Put it in a closet until now. Got it out and ran a guitar and keyboard through it for 3 hours - no problem. Quick look shows no obvious capacitors leaking or bulging.

Ideas?

[BTF]

I recently helped a acquaintance whose Vibrolux had a very similar problem. Fortunately, the problem manifested itself while he was talking to me over the phone (he lives several hundred miles away). His problem was intermittently-leaking coupling caps. One was the .1uF cap in the reverb channel tone stack and the other was the .022uF coupling cap in the reverb channel. The normal channel in this case checked out okay, but the .022uF cap in the reverb channel made the amp unusable. As he played the amp initially, the volume in his reverb channel would fade and a LOUD buzz would appear and predominate. The volume of the buzz would be so severe that he would have to turn off the amp to prevent possible speaker damage.

You might check for leaking DC should the buzz reappear. Another source of trouble might be a deteriorating tube.

Hope this helps, Good Luck!