On eBay; one of Ampeg's best-regarded vintage amps; B15N - Portoflex (no ported cabinet in auction) here: B15N Auction Link Not even close to JP's similar model in cosmetics; style reminiscent of Marantz's 8b; late 60s audio amps of the highest quality.
For the technically inclined: B15N Schematic
What others have to say: HC reviews B15N
Rated output unknown; 3X6SL7, 2X6L6, 5AR4 rectifier. Marketed as a bass amp, along with it's ported cabinet; mostly an enclosed back cabinet with a 2 - 3" 'pipe' of sorts sticking out the front to allow tuning and who said bass players didn't obsess over their tone too. Thought by many to be a top-notch guitar amp; two channels, big power / OT transformers, smallish - compared to most bass amps - output coupling caps to prevent damping the higher frequency interest, cathode cap only on the driver; not on the preamp tubes; that is, much in common with guitar amps. Jacked for pre-amp out and external speaker. Power supply set up for 3X40uf multi-section cap (available in aftermarket) and another loose 40uf.
With Ampeg cabinet:
No idea of what it might go for. cj
For the technically inclined: B15N Schematic
What others have to say: HC reviews B15N
Rated output unknown; 3X6SL7, 2X6L6, 5AR4 rectifier. Marketed as a bass amp, along with it's ported cabinet; mostly an enclosed back cabinet with a 2 - 3" 'pipe' of sorts sticking out the front to allow tuning and who said bass players didn't obsess over their tone too. Thought by many to be a top-notch guitar amp; two channels, big power / OT transformers, smallish - compared to most bass amps - output coupling caps to prevent damping the higher frequency interest, cathode cap only on the driver; not on the preamp tubes; that is, much in common with guitar amps. Jacked for pre-amp out and external speaker. Power supply set up for 3X40uf multi-section cap (available in aftermarket) and another loose 40uf.
With Ampeg cabinet:
No idea of what it might go for. cj