[JohnR]

I've been seeing power supply circuits (for solid state amps) in which one bridge is used for the positive rail and one for the negative. I'm more used to a single bridge with the transformer's center tap grounded. Could anyone tell me the advantage of the two-bridge configuration?

[JoshK]

I think a lot of people have been following the designs on  zero-distortio or tnt (Dejan's PSU designs).  Dejan shows the use of two bridges in his ultimate version, but the reason he uses two in this case I think may be being overlooked.  

Dejan stated that many of the fast recovery diodes are lower in current ratings, so by using two bridges you can effectively double the current capacity the bridge can delivery so higher quality diodes could be used.  However, I know that I bought high current IXYS bridges for my amp project which are fast & soft recovery (20-25 amps iirc).

[peranders]

Using two bridges may have a very small impact of the effeciency of the transformer. The importance is probably not so big.

[Dan Banquer]

Reliabilty: for the large inrush and surge currents for large capacitors, However, this really only applies to power amps.
         d.b.