The Steel Guitar Forum

I picked this up awhile back and am pretty floored by it; great amp! Does anyone have experience with them in terms of adding clean headroom with tube changes, or any issues I should look for?

Just did an electronic resurrection of one a few months back. Be certain those latches are tight! That is the connection to the speaker. No connection to the speaker can result in a blown output transformer.

Makes a great guitar amp for sure. Lots of tone!

Parts can be had at Fliptops Amps, on the web.

I don't recommend messing with these amps to get more output; be happy with the tone and use it for recording. Just get the best tubes available and as Ken said, keep the latches tight.

Thanks a lot. Break my heart. This was my amp with my Farfisa mini compact that I got with bar mitzvah money in '66. I was not a gear head at all---probably couldn't have told you whether or not it had tubes. I must have run it without the latches fastened a hundred times. No, I'm not suggesting that it's ok---just that god looks out for fools.
Sold it to a music store in '76 for $40 because I needed to pay the rent.
Can I have yours?

No, Jon.

My Father bought a B-15 from a dealer at a music store over 40 years ago and I am still using it to play Bass through. It even has some of the original tubes! You know the old saying, "if it ain't broke, don't fix it!" I did replace the original speaker with a 15" Altec 421A. I have four quality bass amps to choose from, but I still take my Ampeg every now and then. Enjoy it!

It has 12AX7's in it for the preamp and the elusive and rare 7868's for power; I thought about using a 12AU7 in the first position to cut drive at the top end, but maybe not? The power tubes will be a concern, but I'll find an extra pair at some point and just put them away for later. It sounds great as it is, except for the early overdrive; I can live with that, though.

Great amps - I've owned a few. I actually think I prefer the SB-12 to the B-15 for most things. I know a guy who has one - one of these days I'll talk him out of it. One of the best amps I've ever heard for jazz guitar - blues too. No bells and whistles, just great tone.

IMO - just get it gone over by someone who knows what they're doing, make sure the filter caps are fresh, and perhaps try a high-efficiency, high-headroom speaker in it, storing the original away. Gotta make sure the chassis will fit in there with the speaker, though. But I wouldn't try to mod this amp with a different power supply, power tubes, etc. I suppose you could try a 5751 or 12AY7 - that would cut the gain a bit. I think 12AU7 would be a bit too low-gain, to my tastes, but YMMV. Simple enough to check out different preamp tubes.

As everyone says, definitely make sure the latches are tight. I watched a guy fry his output transformer by being careless.

I already pulled the speaker and stored it in a 2X12 cab that isn't being used. I put a gold Jensen alnico speaker in it and it is about perfect; I am thinking about trying a BW1201 in it to see how that sounds but I like the organic tone of the Jensen. The original speaker is a little spongy and might be fried a little. I put a long plate 12AX7 from a '40's console radio in it and that brought the volume at the top end up a bit, and made the overdrive a bit smoother. I am leaving the power tubes until they need replacing. It will be a bit before I get it in to a tech, but I set the latches so they can't lose contact. I am pretty much bonded to it at this point.

Used one of these to record many sessions with at the Mastersound studio downtown Atlanta. Nice sounding amp for low volume bass or guitar.

Used my B-15 last night in a big club with no mike and it sounded great and the Volume was at half-way. What a great amp!

I trusted a studio owner when he informed me that he was proud of his great stable of amps including bf/sf Fenders, etc--and I wouldn't need to bring anything to a recording session. Well, the Twin was out on the road, the Pro Reverb sounded lack crap, the Bassman broke up above 3 for some reason and the Magnatone collection that he was the most proud of were great guitar amps, poor PSG rigs. I finally stopped him from carting out yet another inappropriate amp and pointed to the B-15 and asked "does that work?"
It sure did. Holy Grail, B-15, fantastic sound and salvaged session.
Pretty different animal from the SB-12, though. Are the two amps similar, circuit-wise, beyond the power differences?

B15's and SB12's are quite different. The SB12 should never have been marketed as a bass amp, but it is a fine guitar amp with a lovely tone. The B15 is a GREAT steel and bass amp, IMO, and works well as a guitar amp if you are pushing it with a preamp. I love the bass sound from a B15 almost as much as any other bass amp I've ever heard.

I have a B-15 XY which is like a B-15 and a B-12 crossbred, Jess Oliver
(who designed these things) told me once that it's kind of a custom amp,
and indeed, a 15 inch + HF speaker and Dimension Reverb (not to mention
space age tremelo) it is kind of an oddball in that it's a real clean tube amp
(until about 3 O'clock) but it is wonderful with a hollowbody guitar. I don't play my steel through it- Im using a Peavey Companion which is great and runs on batteries.

I sold this locally through craigslist, by the way. The buyer was quite pleased!

Hey, Jon Light --

My brother got a B-15 and a Farfisa for HIS Bar Mitzvah too! LOL. He still owns them both -- although the bottom cabinet and the speaker are long gone. I used to love to play guitar through that amp.

Funny story: the B-15 is designed so that when it's turned on, the plexiglass name plate that says "Ampeg" glows. Ampeg offered a custom feature where they would engrave your name on that plexiglass so it would also light up. My brother bought the amp used from someone named "Tony" -- which had the custom feature. Everytime you turned the amp on, Tony would glow brightly. When I first got to Los Angeles in the early 80s, I played a lot of gigs with Buffalo Bruce Barlow from Commander Cody's band. He always used a B-15 for club gigs. I told him the story about my brother's amp and to this day, he still refers to his B-15 as his "Tony amp." Still makes me smile!

Boo