An LM350 voltage regulator might limit the current during a loud powerful sound. You do not want that to happen.
If you have an unregulated supply voltage and the amplifier has its input level too high so that it clips, then the clipping distortion will contain 100Hz ripple buzzing.
But if you use a voltage regulator to power the amplifier (the minimum unregulated input voltage to the regulator must be at least 2.5V higher than its regulated output) then if the amplifier has its input level too high so that it clips, then the clipping distortion will not contain 100Hz ripple buzzing. Clipping distortion sounds awful, with some added buzzing from ripple then it still sounds awful.
So do not use regulators and keep the input level low enough that the amplifier does not clip.