Right now I use a QSC RMX1450 & a Sansamp RBI into an Ashdown ABM210 & ABM115 (both 8 ohms) Compact cab. Currently I bridge the amp into 4 ohms. I am keeping my current cabs. Would you get the Ashdown ABM500 or get the RPM1 EVOII preamp with either the same power amp or larger? thanks!!!