b15: is the tone in the amp or the cab?

Discussion in 'Amps and Cabs [BG]' started by bon viesta, Aug 25, 2021.

  1. bon viesta

    bon viesta

    Dec 10, 2020
    you know the b15, you heard the b15, and you probably love the b15. even if you don’t use one, or own one, or want to own one, you can probably respect the sounds it has made. but… where does that tone come from? you’ll probably say “both” but that wouldn’t make for an interesting thread :laugh: so rather, what do you think influences the signature b15 sound more, the amp or the cabinet?
  2. bassnat


    Jan 31, 2011
    Having played a B15 for years I can answer your question, yes! If I had to pick one component most influential in the sound I would pick the head.
  3. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    I’ve had three -

    65 NC, double baffle/long ports, various speakers
    65 NF, double baffle/small ports, jbl D140F
    66-67 NF, single baffle, CTS speaker

    The speakers on each were different, and I tried various eminence, JBL, altec, and cts speakers in the first double baffle. But, overall, they were pretty darn close in sound. I haven’t owned one of the later thiele cab designs, I’m sure that also imparts its own sound, but I’m going to go with mostly the amp.

    A B15 into another cab isn’t going to sound exactly like a B15. But neither is another amp into a B15 cab.

    I have a torpedo captor X I’ve been using a bunch at home and it has a B15 cab model. Would be interesting to run the B15 and other amps through the same set of cab models for comparison. If I get to it this week I’ll post the samples here.
  4. SteveCS


    Nov 19, 2014
    Hampshire, UK
    My experience of a range of amps and cabs over the last 35+ years is that the cab is always the most influential. Not only that, it is the one thing you can't really adjust on the fly unless there is a variable tweeter.
    I recently changed from traditional cabs to FRFR cabs and a flat/transparent amp. With that in mind, looking back at my times with various 'bass' cabs (2×15, 4x12, 15+2×8, 4x10+1×15, 1x15) I think most of the EQ adjustments I was making were futile attempts to neutralise or 'manage' the baked-in tone/voice of the cab. With the FRFR setup I barely need touch the EQ, whatever the room, to get the bass sounding great.
    Last edited: Aug 25, 2021
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  5. Lo-E


    Dec 19, 2009
    Brooklyn, NY
    B-15s went through numerous iterations - both head and cab - and all sound like B-15s to me with only subtle differences.

    It’s difficult to ask “is it the head or the cab” when we’re really talking about numerous heads and numerous cabs which all sound similar. Maybe the “famous B-15 tone” is really just a single, ported 15 cab of traditional design and a low power tube amp with a fairly simple circuit and the rest is a bit of romanticism on our part?

    Don’t get me wrong; I firmly want to believe in the magic of my ‘66 B-15 but my rational mind scowls at my romantic mind and reminds me that I’ve gotten similar sounds from all sorts of rigs. B-15s are wonderful amps that deliver great sounds in all kinds of musical contexts but, really, they’re just very basic combo amps with pretty traditional designs. What gives them “the B-15 tone”, IMO, is their simplicity - both head and cab.
  6. marchone

    marchone Since 1951

    Nov 30, 2009
    Nevertheless, a Broughton Fliptop through a modern D-class head with Neos is a pretty good facsimile.
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  7. dbase

    dbase Gold Supporting Member

    Jan 3, 2008
    South Jersey, USA..
    I had the B15 and B18.. I think it was the sealed cab with a hint of tube goodness. ;)
    bon viesta likes this.
  8. bon viesta

    bon viesta

    Dec 10, 2020
    i ask because i’m planning on pairing a fliptops.net 70s style fliptop cabinet with a class d ampeg micro vr head. cheap, pretty powerful, ampeg, and it matches the whole look. i was wondering if the cabinet would make it so i’m at least getting a b15 sort of sound out of the thing, but i also wanted a more wide range of b15 experience so i made the question very broad.
    Basslice and SteveCS like this.
  9. SteveCS


    Nov 19, 2014
    Hampshire, UK
    I would say a sealed 1x15" will get you in the ballpark. Whether a 'barely breaking a sweat' vr will saturate and compress like a labouring B15 is another question.
  10. Dude, what you are creating will look and sound great. But no, it will not sound like a B-15. It will sound great though.
  11. bon viesta

    bon viesta

    Dec 10, 2020
    you can’t win em all :roflmao:
    InhumanResource likes this.
  12. groovaholic

    groovaholic Protect your hearing. Supporting Member

    Sep 19, 2004
    Mount Prospect, IL
    You already know this, but "both" is the correct answer.

    The B15 amp section is sweet, simple, and limited - and the compression due to its relatively low power rating adds a satisfying fullness to the sound.
    My favorites are the late 60s-early 70s version with two channels; I plug into the first channel, then run a patch cable to the "bright" channel. I keep the volume down on the "bright" channel until I dial in a good sound with the main channel, then I slowly roll the "bright' channel up until it's adding clarity, but nothing shrill.

    The speaker cabinet is undersized for the driver, so it tends toward midrange thumpiness more than full frequency extension. With a low-powered amp like the B15, that's a good way to maximize usable volume, and it has become a distinctive tone that lots of people (myself included) know and love.

    (Note: lots of bass combos use this same "big driver in a small box" formula)

    Your best bet is to go into a store and play your bass into a BUNCH of different amps - including guitar amps (at low volume, so as to not damage any speakers).

    Once you do so, you'll quickly develop preferences - then you can start to design your system to work together to suit those preferences...maybe you learn that you definitely don't want it very loud and don't want it to go that deep...or maybe you find that hundreds of watts and multiple 18" drivers are the only thing that will feel right to you.

    Either way, you'll have a much better chance of enjoying the result if you're clear on your goal before you start assembling the parts.
  13. roborend

    roborend Supporting Member

    Jun 10, 2012
    Rock Island Illinois
    I would think plugging a bass into a guitar amp would be frowned upon at most music stores...
  14. blastoff

    blastoff Supporting Member

    Sep 5, 2007
    Ocean Beach SF
    i have a very rational mind. but when i fire up the old ‘66, its like theres another presence in the room. it squeaks and rattles and comes to life in a way i cant really explain any better than that. its there in the room with you. my other amps sound great and ive spent a fair bit of thought in recreating the b15 tone usable with a band. ive got tonehammers and bag ends and barefaces oh my. ultimately it all sounds good especially with a band. ive also cross matched between modern cabs and various old tube amps, b15S’s, sb12’s, b18’s, to get more usable headroom. its all cool, but i return to that ‘66 and there it is.
    i think your micro and fliptops combo is going to be fantastic btw, i look forward to seeing/hearing it.
    Moosehead1966, M0ses and bon viesta like this.
  15. groovaholic

    groovaholic Protect your hearing. Supporting Member

    Sep 19, 2004
    Mount Prospect, IL
    Anyhow, if you end up wanting to go the B15 direction, and still want to build something with your dad, you might want to take a look at this:
    Trinity Trip Top Kit | Trinity Amps

    In Trinity's demo videos, they're using one of the newer Ampeg PF cabs - and its a good looking, great sounding combination, IMO
    james condino likes this.
  16. Redbrangus

    Redbrangus Supporting Member

    Nov 19, 2018
    Under The X In Texas
    My question for the OP is, have you ever heard one, or are you merely going on reputation? I'm not saying it isn't a good choice, I'm just saying it isn't necessarily the Holy Grail one might think if one just reads certain threads in forums. There are plenty of good-sounding amps.

    My advice, unsolicited as it may be, is to assemble the cab, pair it with a reasonably-priced Class D head and start devoting at least some portion of this youthful enthusiasm to practicing your instrument. THAT'S the secret to sounding good, IME.
  17. groovaholic

    groovaholic Protect your hearing. Supporting Member

    Sep 19, 2004
    Mount Prospect, IL
    That's why I specified "guitar amps (at low volume, so as to not damage any speakers)."
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  18. kesslari

    kesslari Groovin' with the Fusion Cats Staff Member Gold Supporting Member

    Dec 21, 2007
    Santa Cruz Mtns, California
    Lark in the Morning Instructional Videos; Audix Microphones
    A big part of your choice is visual aesthetics. Nothing wrong with that.
    But if you want a "closer to B15 sound" go with the P50t rather than the mini-VR.
    I personally think the P50t looks awesome...
  19. bon viesta

    bon viesta

    Dec 10, 2020
    i already do practice! i know my constant dribble about gear makes me sound like those dudes who don’t know what a scale is yet they have 10 basses, but when i’m not playing and listening to music i’m thinking about gear. i’m just a gear head, plain and simple. but still, what’s better than nice gear is playing good. and it’s the most important part. as much as i talk about gear, my current set up is pretty crap! but i still get what i can outta it. i’m just looking for an upgrade that i’ll love. it’s sort of the crazy mayhem before settling down on something. i’m going crazy about gear now, but that’s only because i haven’t made a choice on a set up. and i’m also of the belief that the worshipping of the b15 is a little unwarranted. it’s just a good tube bass amp. but that’s good enough for me, on top of some of the cool sounds ive heard made from them. i know i won’t get that exact b15 sound, or maybe anything even comparable, but i’m not even trying to. i’m just trying to get a good ampeg sound out of a good ampeg rig. this thread was just to hear what people thought of the ampeg b15 as a cabinet and as a head separately :hyper:
    Last edited: Aug 25, 2021
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  20. Ender_rpm


    Apr 18, 2004
    St. Louis MO
    I had the very rare opportunity to play a blue check 65 side by side with a back tolex Thiele 70s model a few years back. The 65 was mine, the 70s I was packing up for a friend. The 65 CAB was a dominant part of THAT Ampeg sound, the Motown 60s sound, it was in there. The Thiele style cab though, that really pumped up the goodness for me. Much lower, as you'd expect from a larger ported cab, but still tat same tubey goodness. Swapped heads between cabs, I could get the 70s head and cab to sound liek the 60s, but not vice versa.

    I currently play through an EBS t90, bax filer EQ and 6550 power tubes make it more of a modern B15. Plugged into a smaller sealed/inefficiently ported 15' cab, and its very close, but through a 215 or 610, it takes on a different character.

    All that to say my vote is the smaller double baffle cabs are the 60s sound, anything else cais an approximation.
    DJ Bebop, AlexanderB and bon viesta like this.
  21. SteveCS


    Nov 19, 2014
    Hampshire, UK
    And the lower power means working harder for the same output, just like a real B-15, so easier to get the power stages working in the money zone at reasonable volume.
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