78 Deluxe Reverb Anyone Remember start of Push/Pull Volume

Discussion in 'Amps and Cabs' started by SuperSoundMusic, Feb 18, 2006.

  1. SuperSoundMusic

    SuperSoundMusic Member

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    Just got a 78 Deluxe Reverb In. I thought by 78 they had push/pull on the volume. This one doesn't. Anyone remember when Fender started doing that? The Pots on the volume knobs date accordingly so I don't think they've been changed. Also, on the control panel it doesn't say anything about Push/Pull.

    :confused:
     
  2. Westy

    Westy Member

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    A push-pull pot was added to some amps in 1974. Therefore, if you have a push-pull pot, your amp is 1974 or newer.

    Source
    http://www.superiormusic.com/page195.htm

    So I guess you have a custom model or special order (no push pull)! Nice!

    Westy
     
  3. SuperSoundMusic

    SuperSoundMusic Member

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    How strange. I didn't realize that Push Pull was quite that early. Everything in the amp most certainly dates to 1978. I know it's not impossible that Fender would do a custom amp, just doesn't seem very likely with all the Hustle & Bustle CBS Coporate Bean Counting. I've seen stranger things though from Fender that were most certainly original.
     
  4. Shea

    Shea Member

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    I believe 1979 was the year that it was added to Deluxe Reverbs and Princeton Reverbs. Other Fenders had it earlier than that.

    The pull-boost circuit in Deluxe Reverbs and Princeton Reverbs is different from the one in the bigger amps in one respect. The circuit used in the bigger amps would boost the preamp gain by injecting some of the signal from the reverb transformer before the third gain stage, and then attenuate the overall preamp level down to about the same volume level as when the boost is off. So you'd get a raspy preamp distortion tone, but no volume boost.

    But the boost in Deluxe Reverbs and Princeton Reverbs would only do the first step (injecting the extra gain from the reverb tranny) without the second step (attenuating the preamp level back down). So, you'd get a very hot signal that would overdrive the phase inverter and power amp as well as the preamp.

    I liked it when I had my Princeton Reverb, but back then I was a teenager and loved really nasty, trebley tones, so I'm not so sure I would still like it today.

    Edit: The Fender Amp Field Guide at www.ampwares.com says the pull boost was added to Deluxe Reverbs and Princeton Reverbs around 1977, but that doesn't jibe with your amp, so who knows.

    Shea
     
  5. Reeek

    Reeek Member

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  6. John Phillips

    John Phillips Member

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    I had a '77 Vibrolux with it, and a '79 Princeton, and I've worked on a few others of both models from around that period with it... but I've never seen it on a Deluxe - no matter how late (which is at least '79, maybe '80). I don't know if none of them have it, or some did and some didn't. It would seem unlikely that they would make both versions at the same time though, so either the changeover is much later than the records suggest and I simply haven't seen one (later DRs are quite rare in the UK, they were beginning to get very expensive for the market over here at the time), or never happened at all, I don't know.
     
  7. sstweed

    sstweed Supporting Member

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    I have a '76 Deluxe and it does not have it.
     
  8. Shea

    Shea Member

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    I've definitely seen a silverface Deluxe Reverb with pull-for-boost. I saw it in a store in Cambridge, Mass.

    What year did they go back to blackface cosmetics? It would have been made before then, because it had a silver panel.

    Shea
     
  9. John Phillips

    John Phillips Member

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    '81. That means that the changeover must have been 1979 or 80 depending on whether my memory is right about seeing an '80 SFDR (might not be!) - I have definitely seen more than one '79 without it though. It may have varied model by model depending on how much stock was left of the parts for the older version ... Fender's amp production was apparently way down ("to about 10,000 units a year" according to Paul Rivera) then and they may have just been built to the old spec until they were used up.
     
  10. Shea

    Shea Member

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    Something to keep in mind is that the boost circuit needs a reverb transformer and three gain stages to work. In your earlier post, you referred to a Deluxe that didn't have boost. I'm not sure if you meant "Deluxe" literally, or as shorthand for Deluxe Reverb. But if you meant it literally, a Deluxe (sans reverb) would never have had the pull boost, in any year.

    Shea
     
  11. gkelm

    gkelm Supporting Member

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    Ha! That brings back memories of cranking his little PR out in the garage in high school days...same feeling. :)

    My SFDR has the pull-boost, and I believe it's a 78...I can double-check later tonight.

    Greg
     
  12. HHB

    HHB Member

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    I own a 79 deluxe reverb and it has the pull boost, it's a gainly little muther even w/o the boost engaged
     

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