Both released at the same time. Kilobass was the "Arena Rock" head. T-Max was it's more manageable (still impressive) little brother. I'm actually selling my T-Max on consignment at my buddy/bandmate's music shop as I type.
At one time I really wanted one of those T-Max heads. Never found my deal. It would probably have to be a pretty good deal for me to bite now as I've been spoiled by the lightweight stuff. Shoot, even the Kilobass is a lot easier to haul weighing in at about 15 pounds...

I had to be loud because the guitarist I originally played with, who actually was a friend that got me into playing the bass to begin with, had a Peavey Special 130 watt combo that he wasn't shy with the volume on.