Been using GK 1001RB for 7 years but went through 2 expensive repairs in less than a year and it recently started going in protection (shutdown) mode with 2 different cabs , so I'm thinking about retiring it and going the route of a lightweight modular rig. Power requirements are 500W driving only one cab at a time with speakon connectors. No EQ adjustment needed. Avalon U5 on hand. Looking for a power amp that will do the U5 HiFi sound justice. Is there a single channel power amp made by a bass amp manufacturer that fits in a 2U rack space? If a pro audio dual channel amp is the way to go, there is a zillion different manufacturers (Crest, QSC, Crown, Mackie to name just a few) with the right power range in a light package. Been looking a the QSC PLX1202 and Crest CA4 so far. Im not a pro audio expert and Im sure these do sound different. Any recommendations for a pro audio amp with the least coloration?