Are capacitance multipliers worthwhile when designing a power supply for an amplifier? Or is it easier to just be generous with the filter caps and use current sources etc to make sure your power supply rejection is good enough that ripple doesn't matter?
Also as a side question, for a regulated pre-amp supply would one just use a normal regulator eg LM317 (or fixed voltage reference if you've got a suitable one I guess)
Also as a side question, for a regulated pre-amp supply would one just use a normal regulator eg LM317 (or fixed voltage reference if you've got a suitable one I guess)
You can't fake a cap when you are after stored energy. Multiplied caps can be excellent in small signal circiuts in order to get long time constants. I for instance, have a 10 minutes RC timer with only 1µF polyester and not very many mega ohms.
Second question: Yes, normally a "regular" regulator will do but it's no harm either to use a better one, it depends what you are after, low noise, high stability, low dropout voltage etc, etc.
Second question: Yes, normally a "regular" regulator will do but it's no harm either to use a better one, it depends what you are after, low noise, high stability, low dropout voltage etc, etc.
I find myself disagreeing with Per on this one. Done correctly cap multipiers can help reduce the hum level in a power supply quite a bit. You need to make sure that there is a voltage drop across the series pass devise greater that the measured ripple voltage at full load. You can bias the pass devise on a little more and add a zenor and have a simple regulator which is cleaner yet.
Later
Bruce
Later
Bruce
I had great sucess with my cap-x circuit. As HDTVman said, these are just a tad trickier to design than a regular pasive filter, but simpler than a regulator and the sonic results are just as good IMHO (with MUCH less power dissipation too).
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