10-25-2013, 10:52 AM
Brenda: It sounds like we are talking about the same thing here. My experience comes from high-current draw Class A solid state amps. In this arena, I use HUGE (250,000uF) caps in conjunction with a CRC filter to provide suitably smooth DC for an amp that draws 9A on a +/- 22V power supply. This amp draws nearly 400w out of the wall in order to deliver 100w of power the the speaker. Caps that are too small, don't have high ripple capacity, too old, etc. cause all sorts of problems with the power supply.
I have a few images of PS ripple on one of my web pages. Check here http://www.facstaff.bucknell.edu/esantan...tml#Output and page down 3-4 times to the section on "Measuring Power Supply Ripple" where you'll find pictures from my scope.
PuhPow: That mica cap should be easy enough to check. I've not seen many of these, but to me the shot of the underside looks a little strange. Can you disconnect one end of it and measure capacitance and continuity? This might provide an additional clue...
I have a few images of PS ripple on one of my web pages. Check here http://www.facstaff.bucknell.edu/esantan...tml#Output and page down 3-4 times to the section on "Measuring Power Supply Ripple" where you'll find pictures from my scope.
PuhPow: That mica cap should be easy enough to check. I've not seen many of these, but to me the shot of the underside looks a little strange. Can you disconnect one end of it and measure capacitance and continuity? This might provide an additional clue...