Fender super reverb "buzz"

Hi! I have a fender super reverb 65 reissue that i bought used. But recantly the amp have began to make a "fizzy" or "buzz" sound when i play loud. The sound is especially noticable when i play low notes.
Does anyons know what may be the problem?

Might just be the speakers breaking up. Could be the cab vibrating . See if it does it more on a particular note or chord. You can lower the neck pup, or turn the bass down on the amp to about 5 if you have it up high.

Otherwise it might be a speaker cone tear or similar.

There are more than a few thigns that can cause thsi type of problem. Tube, cabinet, speaker, component on the board. IF you have a separate cab of 2 or 4 ohms, run the DRRI through that cab...unplug the internal speakers and plug the external cab intot hta Main Spkr jack. IF the 'buzz' goes away, you have a vibration-related problem with the cab, the speaker/s or maybe with a tube. IF the 'buzz' doesn't go away, the problem isn in the circuit or a tube(non-vibration tyep of tube problem)
YOu can tap on tubes with the amp on and try to hear some mechanical rattle come through the speakers to pinpoint a problem with a tube. WIth experience, one gets to where a cab or a speaker problem of this type can be pinpointed by listening and using the 'stereo imaging' of two ears to locate the area of the noise.
YOu might go through the cab with a screwdriver and tighten up all screws. Also, check with your fingers to assure that all speaker nuts are snug. Do not overtighten speaker nuts. A 1/4 to 1/2 turn after contact is enough...adn tighten speaker nuts in a diagonal pattern...just as one should tighten the lug nuts on an auto's wheels.
AS I said....these kind of noises can be 'boscure'. I once found the source of a similar type of noise. The ground in a metal speaker cord plug had not been properly made at the factory. IT was sitting there bouncing ina dn out of contact witht he vibrations of the cab. So....suspect everything.

Thanks alot! I bought two new preamp tubes, and it helped alot. But there is still some buzz though.. I will try tighten up all the skrews!