Using asymmetric secondaries of power transformer with bridge rectifier for bipolar supply
During 1/2 cycle, the diode of the top(+) raw supply is charged from 1Amp secondary, meaning it has larger wire.
During the next 1/2 cycle, the diode of the top(+) supply is charged from 0.5 Amp secondary.

I'd expect the 60Hz ripple to be a bit stronger, because that 1Amp secondary alternatively charges the Top raw supply, and then 8.33milliSecond later is charging the Bottom raw supply.