I'm currently using a Bassman 400 Pro combo and a Sansamp RBI. I love the phat sound of the RBI with my P bass through this combo. BUT - GAS is developing for the Ampeg B100R. I love the Bassman and plan on keeping it, but the smaller size of the B100R and the simplicity of six knobs and one cord appeals to me. Does the B100R get the phat, CLEAN, tube sound that the RBI delivers? GAS could be terminated if I ended up having to use the RBI with Ampeg - kills the simplicity aspect.