Ampeg b-25 cab?

two fingers · #1 12-03-2012, 02:36 PM

I saw a CL ad for a b25 Ampeg cab that has 2 15's in it. Was this cab made for bass or guitar? Or is it one of those 70's kind of "whatever" cabs? Would this thing (stock) handle a 5 string bass and a V4 with any good results? I usually have good PA support so I wouldn't need incredibly loud volume from it, but still, some of those old cabs weren't designed like a modern high power one.

Any thoughts? Will it get the job done at less than insane stage volumes? Thanks.

JimmyM · #2 12-03-2012, 03:26 PM

It certainly isn't a "whatever" cab. But it also wasn't designed to take a whole lot of power either, probably around the 125w mark. It was made to be paired up with the B25, which I believe was 55w. Never played one, but I hear it's a killer sounding cab. However, the one caveat of it is it's a 16 ohm cab. Wiring it to 4 ohms shouldn't be a problem, but wiring it to 8 would be.

Oren Hudson · #3 12-03-2012, 05:01 PM

Technically, the bass cab was labeled B25B, just like the bass head. The B25 head and cab were for guitar. Not sure what speakers were standard in the guitar cab, but 418B Altec Lansing speakers were an upgrade and the Altec Lansing 421A speakers were an upgrade for the bass cab. I have the Altec 421A upgrade B25B cab. It is as sweet as it gets with the matching B25B head. As my friend JimmyM says, both guitar and bass heads were rated 55 watts. However, note that the Altec 421A speakers are 100 watts RMS each, so they'll handle more power that the standard speakers. Bassed upon Ampeg specs under speakers, the B25 standard speakers were listed just as "Two 15', " where for the B25B cab, it shows "Two 15' bass only."

bassdoubler · #4 12-03-2012, 05:05 PM

I have an early one, maybe '69-'70 and the most difficult thing other than it being wired to 16 ohms is the plug you need to use it. Only accepts this strange 4 prong plug that I guess was made for the B25 head. I had to get a special 1/4" to 4-prong cable made and the cab was such low volume at 16 ohms I just stopped using it. Could definitely wire it to 4 ohms and get some new speakers in there....HUGE cab!

D.M.N. · #5 12-03-2012, 05:36 PM

I use one with my Sunn 200s. It's a metal badge (69 I believe), and it's actually the upgraded guitar version, with Altec 418Bs. For my use it's alright, I use it as a practice amp in my dorm, so I don't need to be blasting lows, but it seems a bit honky to me and what I'm used to, which is honestly probably more due to the 418s than the cab itself. I can see it being pretty nice with the 421s. With a 5 string though? I'm not sure, I guess it depends what speakers you put in it.

**flygirafda3** · #6 12-03-2012, 05:39 PM

Some of those cabs have switches to change between 4 and 16 ohms, mine does. Great cabs but a V4 can definitely shred the stock speakers and they definitely wouldn't handle a B at a practicing volume. Great sound at low volume, but not quite worth the high weight imo/e

two fingers · #7 12-03-2012, 06:58 PM

Thanks for the input guys! I was only trying to snag a cab that had kind of the same look as the V4 but not a true fridge like the 8-10. If I can get the guy down even lower on price I may get it and put some upgrade bass speakers in it and save the stock ones. Thanks all!

coreyfyfe · #8 12-03-2012, 08:01 PM

With a pair of eminence beta 15s in there it will sound pretty good with your V4. I use mine with my SVT and like it, not as much as my 8x10 but its a solid cab. With the betas its pretty even, maybe a bump in the upper mids, but pretty balanced overall. They're very wide and shallow. And with the caster cart on the bottom and a head on top I'm always a little concerned its too top heavy, but otherwise I don't have any complaints about it.

JimmyM · #9 12-03-2012, 08:30 PM

Quote:

Originally Posted by two fingers

Thanks for the input guys! I was only trying to snag a cab that had kind of the same look as the V4 but not a true fridge like the 8-10. If I can get the guy down even lower on price I may get it and put some upgrade bass speakers in it and save the stock ones. Thanks all!

Not a bad idea if you dig the look. Beta 15a's would work well in it and probably give you as much loudness as a 410.

craig.p · #10 12-03-2012, 09:22 PM

Back in the '70s I had one with the impedance switch. I ran it with a V4B. It was ok, nothing special. This was pre-Thiele days so everyone was doing the best they could. This was a "leaky box," or (somewhat) aperiodic, design. My guess is they wanted a sealed cab but they also wanted to keep cab volume down for portability. Problem is when you do something like that you wind up with a nasty impedance peak typically at or near the bottom of the BG range; that's the last thing a tube output stage wants to see. The vent tames that peak.

Another thing I remember about that cab is that it was a GIANT PITA to haul around. Those plastic handles hurt like hell, and the shape of the cab made it unwieldy and sort of "tippy." I replaced mine with a V6B cab which had some decent porting, sounded smoother, and it was a kick-back with a towel rack so it was a hell of a lot easier to move.

Frankly, I wouldn't give you a nickel for one today. I s'pose there's a curiosity factor to it, but usability-wise, eh . . .

daveman50 · #11 12-03-2012, 09:41 PM

Quote:

Originally Posted by craig.p

Frankly, I wouldn't give you a nickel for one today. I s'pose there's a curiosity factor to it, but usability-wise, eh . . .

+1. I'd give you a dollar, but no more. Sounded good at moderate volume levels; large and unwieldy for what you got out of it.

Bulltrout · #12 12-03-2012, 09:47 PM

Love mine, but I loaded it with JBL E140's.

two fingers · #13 12-03-2012, 09:48 PM

So......... I'll stick it on top of a nice 4-10 and leave the lid on that B25 recipe. Maybe soon I'll scope out a nice silver grill Ampeg 4-10. What you guys said makes total sense. Thanks again!