When that series came out I bought that head and that cab and the MB15 combo. The combo's amp section croaked so I removed it, taped over the holes, and so then I had a second 115MB cab. I gave the head away to an outstanding drummer who'd just begun learning bass guitar. It was one of my favorite heads, but all my work had transitioned to IEMs and so it was just sitting around. Anyway, I liked that head a lot. The semi-parametric was well thought out. When I used the head with other cabs I'd cut the bass control and bump up the "useful" bass range (50-70 or so) with the parametric. The compressor was the best single-knob compressor I've ever used; the LED would change color when the threshold was hit, and the compressor itself never squashed the dynamics in an obvious manner (unless you wanted it to). I still have the 2 15" cabs. The driver/cab combination on those is a perfect match. It tolerates lots of bottom end boost really well, to make up for the early low end rolloff typical of small sealed boxes. Last time I used those cabs was with my TH500 with lots of bass boost. Certainly not Mesa class volume-wise, but I was still shocked at how much work it was able to do at such a low price point.
If you can find another 115MB extension cab in good shape, grab it, because two of those 15s stacked sounds MUCH fuller than one alone.
