1972 yba1a

Discussion in 'Amps and Cabs' started by simoon, Apr 19, 2005.

  1. simoon

    simoon Guest

    high everybody.i just picked up a mint yba 1a. just wondering what mods can be done and what the general opinion is on these amps.thanks
     
  2. Tone_Terrific

    Tone_Terrific Member

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    Plug into ch2 jumper to ch1, balance to taste, go outboard for od.YMMV.
    Don't mod it unless you know why you don't like it and know what you will end up with.
     
  3. ROKY

    ROKY Member

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    I had 2 '68 YBA-1As, sold one last winter, still have one.

    The YBA-1As are beasts, lots of muscle, loud(how did Pete do it?)
    Mine is as loud as my Marshall Super Lead.

    Seriously.

    I wouldn't necessarily mod mine; just plug and play !

    Earplugs maybe ...:D
     
  4. cameron

    cameron Member

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    There's no reason to mod it unless it's too bright for you. (They can be very bright sounding.)

    They're great amps, but, as the previous responders noted, extremely loud. Easily as loud as a 100 watt Marshall. To look at the schematic, they obviously bear a family resemblance to the Tweed bassman, and the early Marshall circuits. But to listen to them, they're in some ways more like their Hiwatt contemporaries.

    What I like most about them is their ability to give you great grind and crunch, but without losing low-end definition. No mush to those amps. I attribute this to the over-sized transformers, which are much bigger and heavier than what you find in the comparable Marshalls.
     
  5. ROKY

    ROKY Member

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    Well said... spot on, actually :AOK


    The output tranny on mine is 3" and the power tranny just short
    of 4"

    We're talking early Marshall Super Lead dimensions! :eek:

    I think by the early 70s they had downsized them.

    The one I sold to a forum member had been modded, I suspect.
    The sound and response was indentical to my Super Lead; they
    even started to breakup at the same point on the volume.

    This is especially intersting to me because, again a Super Lead
    uses 4 EL34s and the YBA-1A,of course just 2.

    Pete Traynor was able to design the output section as such to
    squeeze, about, 90 apparent watts out of 2 output tubes.:confused:

    The 1A that I still have needs a tweak or two as it's a little brighter than the first
    I suspect the first one had a lower value bright cap installed and
    a few other 'tweaks'.

    The Hiwatt comparison is very appropo.

    I also have 2 YBA-3s made in '67 that get an incredible, sort of,
    Blonde Showman/Hiwatt-esque crunch starting at about 5 on the
    volume.

    I bought that first one to have a bass amp; this after I'd been
    getting into the Traynors for a few months.

    Not only was it a great bass amp, as you would imagine, but when
    I plugged in a guitar and wound it up, the particular tone I was
    getting spun me right out.

    The second I found a second one(virtually it's twin) I snagged it .

    The YBA-3 Custom Specials are awesome, in their own right.
     
  6. cameron

    cameron Member

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    He just designed to what a pair of EL-34s is capable of. The reason Marshalls are so much lower in power is that the original Marshall designs were very closely based on the Tweed Bassman circuit, which used 6L6 or 5881 tubes (depending on which iteration of the circuit you look at). Jim Marshall just made the minimal changes to the circuit to support EL-34s, which resulted in the classic Marshall design, but which really wasn't getting all the power he could have out of the tubes. The designers at Traynor and Hiwatt actually built their output sections around the EL-34 (strictly speaking 6CA7 tubes in the case of the Traynor) tubes, and thereby got a good deal more power out of them.
     
  7. jonny guitar

    jonny guitar Member

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    My 68 (with choke) weighed more than the 4x12 cab. I had to sell it becaus it was killing me to move it around.

    Look at the size of those trannies.
    [​IMG]
     
  8. ROKY

    ROKY Member

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    Makes sense, to me.

    When I get around to it I'm going to try Sylvania 6CA7s in one
    of my YBA-3s for guitar and squeeze in some KT88s in the other
    for Bass .

    Should be very interesting .:cool:
     
  9. ROKY

    ROKY Member

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    Yup there she is :dude
    Looks indentical to mine(same year, so, no surprise, there..)

    Unreal iron in those things:eek: :D
     
  10. jonny guitar

    jonny guitar Member

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    Have you discovered that lubricating your fan with teflon grease makes it virtually silent?
     
  11. ROKY

    ROKY Member

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    No, but ****thank you**** for mentioning that !!!!!!!!!!!!

    My YBA-3 fans are both too loud :mad:

    Where would I lube those girls up ??:eek:
     
  12. jonny guitar

    jonny guitar Member

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    Whoops, sorry about the delay.

    I used a teflon based grease that is actually made for Mountain Bikes...it worked fine. I am sure that you could use a light gauge machine oil too. It is really easy to apply it: just unscrew the middle part of the fan with a flat head screwdriver and squirt it on in. Silent operation.
     
  13. Deaj

    Deaj Member

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    Cpokay's YSR-1 (mostly a YBA-1 with reverb and tremolo) is one of the best sounding amps I've ever played and it's bone stock. No need to mod - these things rock!
     
  14. Shemp

    Shemp Member

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    It's the perfect platform for a Fuchs mod. My YBA1 mod from Andy was pushing 84 watts from a pair of el 34s. With KT 90s it was up near 100.

    Heavy mofo however.
     
  15. cocheese

    cocheese Supporting Member

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    I've had a 68 YBA-1 (now with my brother) and a 65 Yba-1 (still have). They are just great amps, period. The 68 is much louder and more Hiwatt/Marshall than the 65 which is more Tweed Bassman-esque. The 65 is not nearly as loud as the 68 which is a real paint peeler.

    My bro had a master put on his 68 which made it more giggable without shattering eardrums. I heard him with it live a few times and on recordings and it sounds simply fanastic. It has a Marshall kind of thing but is mostly Hiwatt to my ears. It has that clarity like Hiwatts have. Has all the drive but keeps you from getting lost in the mix.

    My 65 has 1 Meg pots in it which is a mod that the previous owner had done. I cannot tell you whether it is a worthy mod because I never heard it before, but I can tell you that it sounds great now! :D
     

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