Fender Twin AC Receptacle

Discussion in 'Glowing Bottle Tube Amp Forum' started by Telecastoff1, May 16, 2019.

  1. Telecastoff1

    Telecastoff1 Tele-Meister Silver Supporter

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    Does anyone know what year Fender changed the AC receptacle at the rear of a Fender Twin Reverb from an ungrounded two-wire to a grounded three-wire?
     
  2. Ten Over

    Ten Over Tele-Meister

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    1970, probably. I have seen a TR with mid 1970 date codes that had a three-prong. I have also seen 1970 date codes with two-prong. I have never seen a TR with 1971 date codes that had two-prong
     
    Last edited: May 16, 2019
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  3. Telecastoff1

    Telecastoff1 Tele-Meister Silver Supporter

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    Thank you! I appreciate the info!
     
  4. Milspec

    Milspec Friend of Leo's

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    My Deluxe Reverb has a 3 prong in '68. I don't know if they did any earlier though.
     
  5. zombiwoof

    zombiwoof Tele-Afflicted

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    Some people upgrade the receptacles on the old ones to 3 prong, although I remember that at one point it was getting difficult to find the 3 prong receptacles that fit in place of the original ones. Maybe they are easier to find now, but the point is that you may run across an older amp that has had the receptacle upgraded.
    Al
     
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  6. BobbyZ

    BobbyZ Doctor of Teleocity

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    Every original three prong I've seen has the red plug. Those are often bad right at the plug, probably from getting yanked outta the wall at 2am by a guitar player under the influence.
    Another tell is the plug in on the back of the amp, the two prongers used a two prong plug there, normally that doesn't get changed to a three hole plug.
    You can also tell by looking inside since almost no one solders as well as the ladies that put them together originally.
     
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  7. Axis29

    Axis29 Poster Extraordinaire Ad Free Member

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    @BobbyZ, I think he’s talking about the courtesy outlet....
     
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  8. Milspec

    Milspec Friend of Leo's

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    Okay, I got bored, but after looking at amps on Reverb from '68 - '71 it looks like the 3 prong receptacle started in '70 or '71. What is interesting now is that my '68 Deluxe has a 3 prong and the original owners manual shows a 3 prong, yet I couldn't find a single one on the Reverb site that had a 3-prong. I guess CBS was a little sloppy at that point and building from a parts pile left by Leo still? I don't know, just seems weird.
     
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  9. teleman55

    teleman55 Tele-Holic

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    My '70 Pro Reverb had a two prong ac outlet.
     
  10. Wally

    Wally Telefied Ad Free Member

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  11. Wally

    Wally Telefied Ad Free Member

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    https://el34world.com/charts/Schematics/files/Fender/Fender_twin_reverb_sf_100_schem.pdf

    The AA270..February, 1970...Twin Reverb schematic below still shows a two wire supply. The 100 watt schematic above is the first I find for the Twin Reverb that shows a three wire supply. If you blow up the small insert of the schematic, you will read 1972...at least I think that is what I read. I am not near my reference materials to see things better.
    https://schematicheaven.net/fenderamps/twin_reverb_aa270_schem.pdf
     
  12. Ten Over

    Ten Over Tele-Meister

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    I think Fender had some serious and persistent inventory control problems. They weren't going to start installing an upgrade until the old parts were used up. But they didn't know when exactly the old parts were used up.
     
  13. spellcaster

    spellcaster Tele-Holic

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    My 1970 Twin Reverb chassis came with a two-prong receptacle. I ordered a three-prong convenience outlet from Marsh and changed it over when I did the three-wire cord conversion.
     
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