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60's stereo console tube amp removal

Discussion in 'Tube Audio' started by skywachr, Jun 13, 2018.

  1. skywachr

    skywachr New Member

    Messages:
    33
    Location:
    AZ
    First off I am a complete novice in the area all things tubular but consider myself quite knowledgeable in the area of vintage solid-state audio gear. I do not however get into doing my own re-capping etc.

    I have come across a GE console stereo model Abbington from the early 60's in perfect working order in a thrift store. The tuner emits a stereo FM signal with very pleasing stereo tones given the limited 8" speaker that is in the unit. The cost of the unit is $38.

    I am very interested in making this my first tube project. I am not knowledgeable enough to understand whether there is a preamp integrated into the tuner electronics as it seems to be on board in one area of the console with the amp as a separate unit.

    Is this a viable project? Will I be able to use any of my solid-state preamps feeding into the tube amp? Would it be wiser to use the preamp/tuner section as part of this whole set up? I really don't know what I'm stepping into here. Any help would be greatly appreciated. I am going to attempt to attach a photo of the simplified schematic which was stapled to the bottom of the unit to this posting which will tell you exactly which tubes are part of all of this.

    Thanks in advance.
     

    Attached Files:

     

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  2. FlaCharlie

    FlaCharlie Well-Known Member

    Messages:
    595
    Location:
    Gainesville, FL
    Yes, it's a viable project. It does look like the preamp / tuner is in a separate chassis from the amp. The amp is single-ended (one 7189 output tube per channel) so not a lot of power. I think this amp uses a circuit board instead of being wired point to point. You should be able to use a SS preamp with it but I'd suggest pulling the pre / tuner section too.
     
  3. FlaCharlie

    FlaCharlie Well-Known Member

    Messages:
    595
    Location:
    Gainesville, FL
    Last edited: Jun 13, 2018
    Dandy likes this.
  4. skywachr

    skywachr New Member

    Messages:
    33
    Location:
    AZ
    Thanks Charlie. I was mistaken. It's actually an RC4238 model. The Abbington seems to be the RC4231A which may be a different style cabinet for the same model. I haven't compared the drawings yet as I'm looking at this right now on my phone. I could find nothing related to that exact model number in a web search except for ads in old newspapers.
     
    Last edited: Jun 13, 2018
  5. skywachr

    skywachr New Member

    Messages:
    33
    Location:
    AZ
    The model I'm looking at (RC4238) has the same tubes as in that post for the RC231A you referenced.
     
    Last edited: Jun 13, 2018
  6. FlaCharlie

    FlaCharlie Well-Known Member

    Messages:
    595
    Location:
    Gainesville, FL
    The Sams I linked to lists several model numbers including 4238A. I'm sure the addition of the 'A' suffix is a fairly minor revision and the schematic should be essentially the same. The different model numbers may refer to the console itself and reflect differences in cabinet styles or other features such as different record changers.
     

     

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  7. skywachr

    skywachr New Member

    Messages:
    33
    Location:
    AZ
    Once I was able to see the whole Sam's I saw the 4238 reference. I was specially interested in the photos which showed how he isolated the control amp and amp pieces together on a board to hopefully make it usable. I have a hold on the piece and will definitely go for it. Thanks for the encouragement.

    By the way, the outputs to the speakers look like mini rca plugs. Is there a term for these?
     
  8. cubby01

    cubby01 aka Buck

    Messages:
    9,742
    Location:
    Kansas City area
    RCA connector. I doubt its actually 'mini' though it may look it at first glance.
     
  9. skywachr

    skywachr New Member

    Messages:
    33
    Location:
    AZ
    Thanks. That did occur to me. Just not as beefy as what I'm used to seeing and handling all the time. No separate ground connector. Just a common ground running all over. Makes sense that is possibly where the term common comes from.
     
  10. fredtroy

    fredtroy Member

    Messages:
    77
    Have fun with your tube endeavor.
     

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