[Amps] TL-922 is buzzing

[Szegedy]

Dear Friends!

I have TL-922,my linear is buzzing but only in SSB MODE,in CW MODE is ok.I checked the screws on the transformer,it is ok.
The buzzing noise comes from left side of amplifier,in STBY (when no drive) is also buzzing,but linear works perfectly.
My questions:
1.How can I test that my filament transformer causes the buzzing or other things?
 Is it good solution if I solder down the 2 yellow wires which go from filament transformer 11V output to the tubes?
 Because after soldering the filament transformer output will be  free,no 14A  current and without this big 14A maybe the transformer will no buzzing,I could decide this transformer causes the buzzing noise.If the buzzing don t stop,something else cause the buzzing,not the transformer,is itv
2.What will happen with the tubes if the tube don get 11V heater voltage and linear is POWER on?Can I damage the tube or not?Because anod Voltage is on the tube,but without 11V heating voltage?Is it problem for the 3-500Z tube?
3.Do you have a better or other idea?
                                                                               Thanks:Laszlo  HA5BZR