Regulated or not regulated?

[soundman]

Hi,

After searching and looking at several threads about power amplifiers, I noticed you guys suggest not to use a regulated power supply when designing a power amplifier (Specially does which are made by ready chips). you told that a common power supply is more enough to be used!
Whats the reason?

Thanx

 

[audioguru]

An amplifier rejects hum and noise on its power supply voltage so voltage regulation is not needed.

 

[soundman]

Is this true just for monolithic amplifier chips?

Now another question arises, If an OP-AMP or a CMOS/TTL chip is used in away with a Power amplifier (the power amplifier happens to be the last stage) then Does the designer need an regulated power supply for The OP-AMP or the logical chip, or the Power amplifier is enough to remove Distortions due to leakage of a perfect power supply?

 

[audioguru]

An opamp and a power amp reject hum and noise from a power supply so they do not need a regulated supply.
Old TTL logic needs a regulated 5.0V supply.
CD4xxx ordinary Cmos works with a supply from 3.0V to 18V and also does not need a regulated supply.
Newer high speed Cmos (74HCxxx) works with a supply from 2.0V to 6.0V and also does not need a regulated supply.