I use a "19V/9.5A Toshiba power supply" with a "DC LC Filter Lowpass EMI Power Filter Low Pass Passive Filtering Board F SNT" on my amp. You won't believe how clean this power supply is!
The point is if you change to components of a different type and printed circuit boards with different circuit configurations you may end up with an amplifier that sounds better, but if you fit a hybrid engine and battery set up to a Mk. 1 escort it may drive and perform better but is it a Mk 1 escort? no. QUAD 303s are antiques let's leave them as antiques. If you want a superb sounding amplifier buy one, there are plenty out there, Lets leave Quad 303s alone and show some respect for a great design that has stood the test of many years.
