On the tests we did with a friend, the 3886 behaved differently with small and high capacitance on the PSU. Up to 1500uF, response on treble and mid was cleaner, though bass was a bit "diffuse". More than 2200uF improved the bass a lot, but was not so good for the upper side.
A regulator with small capacitance at the output, such as that based on the LM338, should solve matters for all frequencies. Even so I am not so sure if using lots of capacitance, like 20000uF or so, would not be a better option on an unregulated PSU powering the bass side of an active system. Except if you over dimension everything, a regulator might compress the bass response.
