I have NAD 302 Amp and would like to tweak it as it contains ceramic caps and ofcourse plenty of space for tweaking like adding Caps for PSU/ Fast rectifiers/ PP cap bypassing. Can anybody out there help me with schamtics alone.
In my opinion NAD is one of a few companies that knows how to achieve great sound from cheap materials. I don’t know with ceramics caps, if it is the cheap green caps, I’m sure you cannot hear any difference if you replace it with first class MKP (or even MKT). Those caps are suitable for coupling capacitors (to ground) and in the DC rails near transistor pins. It is also very likely that the circuit has a zobel in the output, but there’s no need to put expensive cap here.
My NAD C320 uses massive PSU torroid and capacitance. The rectifiers are suspicious (because it’s cheap), but looking at the “complexity” of the regulator circuit as well as the complexity of the amplifier (multi stage amplification and feedback), I don’t think that replacing the rectifier worth the effort. In a simple circuit, component quality is more important to cover the drawback of a simple circuit. In a complex circuit, it is less so.
The HF section (of the tone control) uses cheap green caps, the LF section uses MKM. Isn’t that smart?