[Skywave]

The TAA611B and the TAA611B12 appear to be the same.
The data sheet is attached.

Your fault sounds like a faulty i.c. From experience with these i.c.s, that is usually caused by the PSU rail going too high. The O/P stage is a 'totem-pole' affair; one of the pairs has probably gone C-E s/c.
The rectifier is buzzing probably because it is passing excessive current; it may even have failed s/c. That would wreck the i.c. for sure!

Disconnect the PSU rail from the i.c. & measure that rail. If that rail is even slightly in excess of 15 v., the i.c. has failed. 15 v. d.c. is the absolute max. for this i.c.

Al.