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1962 Ampeg Reverberocket R-12 Low, Distorted Output

Discussion in 'Amp Tech Center' started by Faceman, Aug 20, 2019.

  1. radiocaster

    radiocaster Poster Extraordinaire

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    It looks like they would be useful in his case, as V2 and V3 either have opens or there's something else wrong in the circuit.

    I think it would be a good idea to swap V2 and V3 and see if the voltage readings are the same on the same pins, that would tell you if it's the tubes or circuit.

    Pin 2 is also a bit high on V1.
     
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  2. timfred

    timfred Tele-Meister

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    Pin 2 on V6 should read the same as all the other heaters: +21VDC.

    I'd re-check/fix that first.
     
  3. Faceman

    Faceman Tele-Meister

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    I went back through and took everyone's suggestions. I also retested the tubes for leaks and shorts. I have determined that I cannot rely on my tube tester. When I re-installed the tubes, I purposely put them in different positions (again) and now I have more volume but more dirt. I ordered some NOS tubes last night and am going to see what happens. All components test fine so process of elimination...must be tubes. We'll see. I will follow up.
     
  4. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    A tube tester can tell you if a tube is bad - it can't tell you if a tube is good. Only your ears can work that magic.
     
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  5. Wally

    Wally Telefied Ad Free Member

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    Faceman, a tube tester can not resolve the issue which D’tar pointed to. Did you go back through, test the voltages, and find any problem in that area to which D’tar directed you?
     
  6. Faceman

    Faceman Tele-Meister

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    Wally,
    Yes I did. There was no short at the "F" node. I will have to retest the voltage drop at the resistor again because I do not remember what it was but will post the voltages again tonight. I just bit the bullet and bought a Fluke meter today. My meters digital screen took a crap yesterday.
     
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  7. Faceman

    Faceman Tele-Meister

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    You nailed it. I pulled one leg of the resistor out of circuit and it was WAY high...like 7 meg. Weird because I was getting funky readings in circuit but nothing that whacked. Popped another 22k in there and I’m in business. Thanks so much for the help. Case closed!


    Sent from my iPhone using Tapatalk
     
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  8. Faceman

    Faceman Tele-Meister

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    On another note, I was able to get in touch with Ampeg and they gave me the service manuals WITH VOLTAGES!! I thought I would post them here so others may get some use out of them.
     

    Attached Files:

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