Friend tolds me that noise of any switching PSU can be attenuate if I put linear regulator before output?
For example, if I wanting to power +-12V opamp for amplifier, I can uses SMPS say with noisy 15V output and then from SMPS output feed LM7812, LM7912.
Output from LM7812, LM7912 will now have very very low noise compared to what having at their input?
If this is true, this amazing as no need to use transformer anymore.
Is this really correct as no more heavy PSU using transformer for Class A, B amplifier then?
For example, if I wanting to power +-12V opamp for amplifier, I can uses SMPS say with noisy 15V output and then from SMPS output feed LM7812, LM7912.
Output from LM7812, LM7912 will now have very very low noise compared to what having at their input?
If this is true, this amazing as no need to use transformer anymore.
Is this really correct as no more heavy PSU using transformer for Class A, B amplifier then?