Over the weekend I played a gig at a St. Louis club, "BB's Jazz, Blues and Soups." The house amp for the harp players is a Bassman RI. I thought I'd forgo dragging my amp in and play through it -- until I plugged in (JT30 with controlled mag cartridge from a green bullet) and started sound check. By two-and-one-half on the Bassman volume control, I was badly into feedback with insufficient volume for the venue. Obviously, no one had set the amp up for harp. So I brought in my Sonny Jr. 1 and used the line-out feature to slave the Bassman off of the Sonny.
Nirvana! Man, what a killer combination that made. Lots of full, rich, bottom-heavy fat tone pushed out by the 4x8 plus 4x10 combination amounting to a combined 70 to 80 watts. And, I was able to turn up the Bassman to a higher over-all volume level without the feedback problem. I think the main advantage of combining the two was the fullness/presence of the sound without being overly loud, though.
Some of the best setups I've played through or heard others play through have envolved chained amps. One of the better players here in St. Louis chains a Bassman RI and a Vibroverb RI. Marvelous sound. In the past, when I've felt like carrying the additional equipment, I've chained an old '61 Gibson Falcon to my Sonny Jr. 1. The resulting sound is obviously better than either alone and seems more than the sum of the parts.
Any of the rest of you use a chained amp setup? I be interested in your setups and comments.