I've been looking for an Ampeg B-18 to keep my B-15-N company without success. I've been thinking of getting a B-18cabinet from Fliptops and picking up an older V-4B and running them together. I know the V-4B is not a B-15 amp but I'm hoping they would be close, maybe even running through a Fliptop pedal like the Tech21 VT or Barber Linden. Do any of you Portaflex fans out there have any experience that you could share with me?
Sounds like a very cool rig. If your picturing that amp placed on your cab, keep in mind the V4/V4B's are nearly 27" wide...
Owning both a V4 and a B15, I don't think the V4 in a 1x18 cab would sound anything like a B15/18, with the caveat being that I haven't ever tried my V4 with a 1x15 or 1x18 cab.
I think it would be fairly close. The B-18N came with a 50w head that uses 7027A's. And the V4 used them, too. And really, all tube amps Ampeg made have all been trying to emulate the B-15 at higher volumes, so there's a certain similarity to all of them.
I am not exactly a B-15 fan, though I appreciate their tone in small rooms or studios. That said, I did use a B-18 on gigs a few times, and while it was a bit more capable than the 2 B-15s I had used a lot up to that point, the B-18 was still pretty "underwhelming" for the work I was doing. The musical application was what you might call "fairly soft Art College blues band music of the late 60's/early 70s." The bands were not loud, and the amp was certainly not enough. When it farted, it really FFFFFAARRTTED!!! All IMHO, YMMV. Have you considered finding an Acoustic 301? Now I realize you need a larger vehicle and a fair amount of determination to schlep one, even with the tilt back wheels and recessed built-in handles--but THAT was an 18, IMHO. It bet it would love a V-4B!
Nobody would ever accuse the B-15/18 of being capable enough to handle gigs where a lot of stage volume is needed. And I never bring mine to a gig where that's the case. But I rarely play gigs where a B-15 couldn't cut it. And slap a mic on one and crank it in the PA and the audience will experience multiple orgasms over your killer tone