I'm looking to build a dual-rail, regulated, 18VDC power supply based on the 78xx and 79xx regulators. The circuit is inspired by AMB Audio's sigma25 (amb.org/audio/sigma25/) and sigma26 (amb.org/audio/sigma26/) regulated power supplies. I have also Googled around and came across these:
However, I am torn between using a 2x9V transformer and connecting the secondaries as such, using only 1 bridge rectifier to supply both regulators: ...and using a 2x18V transformer, each secondary feeding its own bridge and regulator, as such: What are the pros and cons between the two, apart from (slightly) more parts count in the latter schematic?
Many thanks for any enlightenment given.