RC supply filter in Class AB amp

[tiroth]

Any comments on the use of an RCRC filter in the supply for a solid state class AB amp? Looking at some simulations it seems that ripple is reduced to the point where a higher bias can be sustained for a given ripple voltage (versus a capacitor-only filter).

The difference in my particular case would allow me to go from a 100mA bias up to as high as 500mA, with less overall ripple. The downside (as I see it) is greater supply modulation once the amp leaves constant current operation.

This is for R=2ohms, C=10000uF.

Since 500mA is up to almost 50% of full power, is there a reason not to do this?

[HarryHaller]

Actually it works quite well and limits the peak current that the rectifiers have to supply for the same total supply capacitance. I use about 0.25 ohms on my Aleph 3. Not only is the absolute level on ripple reduced but, more important, the high frequency components are greatly reduced. Highly recommended!

H.H.

[tiroth]

Thanks Harry!