This was one of the B-15's I've owned. I'm almost 72. I've owned a LOT of gear, and a lot of it was Ampeg. I grew up in Woodside, Queens, and used to rehearse directly across the street from the Ampeg factory, in a storefront under the #7 IRT el at 54th. st. Ampeg was at 54-09 Roosevelt ave. Oh, yeah, we all had Ampeg tube amps.
The B-15, WAS state of the art at one time. In the bands of the day, late 50's through the mid sixties, it was adequate, and in my session days- almost all the studios had some really awful sounding surplus B-15's soldiering on. I really hated those things. I recapped my '64 and put in a new speaker I got from Fliptops. It was a nice sounding amp- and had a very musical 'tube sag' at a certain point. That point, was like a VNE speed on an aircraft- once you exceed it, it's not good. The B-15, on most gigs, ended up being a bass kazoo. It's coveted now, because of the massive, really kind of undeserved credit given to it as a contributor in the sound of greats like James Jamerson and others. Trust me- the crummy studio amps I've encountered- in my opinion, is why engineers started taking us direct. I remember vividly, B-15's were in the back of almost every music store for 200 bucks. Now- 3K? I just don't see it. Just my .02.