Cant comment on either of the amps, but did have a SS Mac Amp many moons ago, and I sold it as fast as I bought it, not enough body, thin sounding...
If your budget allows, step up to a Pass X250.5 It will make the preludes sing, like you wont beleive.
I had 3 differnt Pass amps on my preludes. X150.5 X250.5 and the X350.5.
The X250.5 was the champ on the preludes. The overall sound is spatial... with great mid body, and slam on the bottom end.
I always get asked what sub are you using, the answer of course is there is none. Then you remove the screens and they see 3 1/2' drivers, and they say, no way, can those give you that kind of bass. Then they proceed around the room , hunting for a sub, which does not exist. Its quite funny.
Of course it also requires other component & cable matching, to give the synergy I describe above.
FYI Alan Yun owner of Silverline demos them at the CSA show in Vegas using Pass.