2nd Thoughts...

Discussion in 'Amp Central Station' started by Old Deaf Roadie, Dec 5, 2019.

  1. Old Deaf Roadie

    Old Deaf Roadie Tele-Afflicted Silver Supporter

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    Okay, so I bought a 69 Fender Dual Showman Reverb head from a friend for an outrageously low price. Yes, he knew he was selling well under value... My intent was to flip it for a profit & get something a bit more "tweedy".

    Then...I see a pop up ad for a power soak & I start thinking that maybe I should get a power soak & keep the amp. Will a soak color the sound at all?

    Any insight would be helpful. I have a bunch of 2-12 & 2-15 cabs to choose from to run the amp through.
     
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  2. FenderGuy53

    FenderGuy53 Poster Extraordinaire

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    We need an intervention here... :rolleyes:
     
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  3. BobbyZ

    BobbyZ Doctor of Teleocity

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    I've got two Twin Reverbs one BF one SF, honestly didn't think I'd like them as much as I do! Easily four times the wattage I actually need.
    Never tried an attenuator but I do tend to prefer speakers with lower efficiency. It all depends on the sound you're going for I guess.
    Has the amp been serviced?
     
  4. uriah1

    uriah1 Telefied Gold Supporter

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  5. Wally

    Wally Telefied Ad Free Member

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    Step 1....full evaluation and recap.
    Step 2....that amp can be modded to yield ‘tweedier’ sonics.
    Step 3....get a really good reactive load attenuator with a direct out.

    these three steps will probably eat up your ‘savings’ on your cost for the amp versus marketplace norms, but that is how one wants to buy a vintage amp....unless it already has been properly serviced. Great amp...congrats.
    Out of curiosity, take a look in the head cab. Does it have an actual baffleboard in the head cut for 2 x 8’s??? some Dual Showman heads were prepped at the factory for this. eminence sells an 8” that will handle the power you have there.... voila!, a ‘small’ package for use when you don’t need a big cab.
     
    Last edited: Dec 5, 2019
  6. Mexitele Blues

    Mexitele Blues Tele-Holic

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    I agree with Wally. Mod the normal channel to your tweediest desires. With the attenuator you'll have yourself a poor man's Tone King.
     
  7. rolandson

    rolandson Tele-Holic Silver Supporter

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    Ahhh...
    What about pulling two of the power tubes? It was/is a common practice used on the Twin Reverb that cuts output rather effectively without affecting the "flavor".

    There's some discussion about it here (despite this being Twin Reverb specific, I believe the circuitry is nearly the same)...
    http://fenderguru.com/amps/twin-reverb/

    Additionally, disconnecting one of the speakers, especially in conjunction with pulling power tubes, can be very effective.

    ETA: Yes, an attenuator, or 'power soak' will affect the tone...flavor...fidelity. Whether positively or negatively is a matter of personal preference. I found using the Weber Mass 100 an unacceptable solution ... for me.
     
    Last edited: Dec 5, 2019
  8. telemnemonics

    telemnemonics Doctor of Teleocity Ad Free Member

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    Yeah, my feeling is that a Twin or DSR won't sound tweedy even cranked, never mind with a primitive power soak.
    Modding would probably be more cost effective than buying a decent attenuator capable of handling 100w.
    But then why buy a large amp only to try to make it sound like a small amp?

    Some of us still like big amps!
    I suppose spending to mod up a dirty channel keeps it useful as a big clean amp on the other channel.
    Not sure how well a modded amp sells though after the investment.
     
  9. jrblue

    jrblue Tele-Afflicted

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    Honestly, those amps (and many other higher powered units) sound fine to me just turned down -- no attenuator -- but of course that's personal, as this works fine for "my" tone and signal chain. I'd run it through 1 speaker only, ideally a less-efficient one. And that's it for me. I would see it and buy something smaller and different before going with mods and an attenuator. Why try to turn one good amp into another kind of good amp?
     
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  10. Wally

    Wally Telefied Ad Free Member

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    why mod that Normal channel? So that one can have a two channel amp with two distinctly different channels. And...fwiw....these AB763 based amps were being modded long before any of us dreamed there would be an Internet. Dumble amps began in that manner.
    I agree that these big Fenders can sound great at low volumes....simply push the tone controls up at volumes below 5. Reduce the tone settings with volumes above 5.
    Re: disconnecting one speaker. Pull two power tubes and disconnect one speaker. The power is reduced by half, the amount of air being moved is reduced by 50%, and the proper impedance match is maintained. Tis won’t cut volume by half, but it is a reduction.
     
  11. Wally

    Wally Telefied Ad Free Member

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    well, these big amps have lost their collectible value anyway because the modern crop of h7man beings can’t deal with more than 25 pounds, it seems!!!! Eeeehaw..... so, why not mod one???. As for getting a grainier, mid heavy Sonic out of one of these amps, it happens.
     
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  12. rolandson

    rolandson Tele-Holic Silver Supporter

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    ahh...isn't the 69 Dual Showman a Silverface...AC568, AA769, or AA270 circuit?
     
  13. Wally

    Wally Telefied Ad Free Member

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    all of the BF/SF amps are based on the AB763 circuit...same basic preamp. The changes that were made to these amps over the years had more to do with the output section, push/pull boosts, and master volumes. They are all very closely related as to the basic topography...and that circuit was designed in 1963. Some feel that it was perfected at that time, too. Some don’t feel that way. But...none of the BF/SF amps resemble the 6G or the tweed amps to such a degree as they resemble each other.
     
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  14. rolandson

    rolandson Tele-Holic Silver Supporter

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    Of course the Silverface circuits were "based" on the earlier designs, just as the Blackface circuits were the evolution of earlier designs. But it isn't the 763 circuit.

    As I read the OP, I understand the discussion to be output related. I don't know which of the circuit designs is relevant to this specific amp, but no, it's not a tweed.

    I thought the question was whether a power soak will color the sound. I offered that, in my opinion, it will...negatively so.

    I also offered the possibility of reducing output by pulling tubes, and I hope the OP reads the link because there is a good discussion about preamp tube substitutions that can be rather useful too...to reduce output a bit.
     
  15. Wally

    Wally Telefied Ad Free Member

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    Well, rolandson, we’ll agree to disagree on this one. Go through and delineate the differences between the OP’s ‘69 SF DSR and the AB763 TR....the differences are very minor as to the circuit.
    and.....My statement was “AB763 based circuits”, and that statement is accurate. I did not say it was THE AB763 circuit. Fact of the matter is that one would have to have the amp in front of one or be looking at some good pics to know what actual circuit it is...a ‘68 or a ‘69. When someone says “AB763 based circuit”, I know exactly of what they speak; and I have never before seen or heard any tech take exception to the use of that term in the way I used it. Ymmv.
     
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  16. bftfender

    bftfender Friend of Leo's

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    one of the one's that has 3 fender SF with normal chan modded on all 3. To my exact break point needed. Playing goes way up when you get to "your" sound. Exactly the way you want it.
     
  17. rolandson

    rolandson Tele-Holic Silver Supporter

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    okay.

    And...back to the OP's issue...? Without major surgery? Which is preferable, an attenuator or some other approach?
     
  18. Wally

    Wally Telefied Ad Free Member

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    My first post are my thoughts.....

     
  19. rolandson

    rolandson Tele-Holic Silver Supporter

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    Okay...mod...got it.
     
  20. Wally

    Wally Telefied Ad Free Member

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    I didn’t say to mod it. I said it could be modded to gain versatility.
     
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