Anything's possible, but I suspect that your 'buzzing' is caused by a transformer.Transformers work on the principle of electro-magnetism.Coils of wire (1 primary,and at least 1 secondary)are magnetically connected with alternating current (no DC!)and their 'turns ratio' and magnetic coupling (core saturation) determines the voltage and current output(s).
The older-style transformers are usually buily with silicon-steel plates,lacquered for insulation,which magnetically couple the coils,and current together.Sometimes these plates, or cores; get loose and vibrate at a multiple of line frequency.(60 hertz).Sometimes the insulation goes bad. Sometimes the mechanical mounting of the transformer (nust,bolts)gets loose.This causes buzz.
Be very careful with capacitors.Depending on their ratings,if you exceed their D.C.W.V.(DC Working Voltage), or A.C.W.V. they can actually explode.
There are capacitors for A.C.(usually motors), and D.C.(most everything else).A D.C. capacitor connected across an A.C. line will usually explode,sending metal shards and chemicals (Dielectric) everywhere.Not a good thing.
When Caps go bad, they sometimes leak, short out,or just quit working.When a D.C. Cap quits,the D.C. becomes less than properly filtered....and A.C. hum is introduced into the circuit.
I've worked on huge tube-type high-voltage amplifiers,and learned the hard way to discharge the high-voltage on the caps(when not plugged in!)with a 1 megohm resistor.When these caps go bad, the A.C. hum is terrible.But the hum actually comes out of the speakers as part of the signal.