Im making an 75-85watt power amp using bridged lm3875's. It's going to get a balanced signal from a separate opa2134, drv134 based pre-amp
For the power amp's power supply Im going to use 10,000uF of reserve capacetance on the rails along with seperate 100uF and 100nF close to the pins on each chip
(I know that these opamps have good pssr and dont need smooth d.c, but IMO the caps do more than just smooth the d.c)
Now here's my question, Because in a bridged amp the current flows between the +ve and the -ve of the supply all the time (compared to single ended were the current flows between +ve to ground half the time and then from ground to -ve the other half of the time) can I just put the caps between the +ve and -ve rails, would this have the advantage of isolating the ground plane (witch is now just a zero volt reference) from all the nasties in the supply lines or do I need to stay with the bipolar desine with the supply caps going to ground?
Billy
For the power amp's power supply Im going to use 10,000uF of reserve capacetance on the rails along with seperate 100uF and 100nF close to the pins on each chip
(I know that these opamps have good pssr and dont need smooth d.c, but IMO the caps do more than just smooth the d.c)
Now here's my question, Because in a bridged amp the current flows between the +ve and the -ve of the supply all the time (compared to single ended were the current flows between +ve to ground half the time and then from ground to -ve the other half of the time) can I just put the caps between the +ve and -ve rails, would this have the advantage of isolating the ground plane (witch is now just a zero volt reference) from all the nasties in the supply lines or do I need to stay with the bipolar desine with the supply caps going to ground?
Billy
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