Today I picked up a Yamaha BBT110s bass cab (10" + horn) for $105 to share with my daughters Keyboard. The amp I usually use for her keyboard is my Acoustic 260 (100w 10" reflex cab). What a difference the yamaha cab makes with both her keyboard and my bass, but it really shows the inadequacy of the amp in both cases. Even a small 35 watt audio amp I have sounds better than the Acoustic with the keyboard. My regular practice amp is my Bronco 40 (which I have installed a speaker out jack on to use with the Yamaha, what an improvement!), but I know now the acoustic head is ungig-able for either her or I. When I tested the Yamaha in the shop, it was with a Rumble 500 head, I was quite impressed, and actually liked the controls and tone better than the Markbass little Mark 250 I tried with it first. My question is: Is the Rumble 150 comparable to the 500 in tone? Power-wise it's well matched with the Yamaha cab (rated at 250), and the controls are similar to the 500. It's listed at a steal price (under $100), and is accepting offers. I have read the comparisons, but some time has passed since many of those threads were started.