AC30 - tube layout? - photos

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by kirk95, Oct 1, 2011.

  1. kirk95

    kirk95 Jazz Lines You Can Use in the Blues Silver Supporting Member

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    My AC30 just started making a buzzing sound. So I opened her up....and wow looks like this amp hasn't been opened in a long time. There were cobwebs in the there. This was my late brother's amp so I really don't know the history. I believe it is a mid 60's - not sure where or from who he bought it or when was the last time anyone serviced it - if at all??

    Can someone decode the tube layout for me?

    All the tubes light up. But I am getting this buzz that I wasn't getting just a day ago.

    The preamp tubes are all Mullards. The EL84s are 2 Pinnacle, 1 Phillips and 1 unmarked.

    Thanks in advance for your help...


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  2. diagrammatiks

    diagrammatiks Member

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    Oh jeebus that's a beautiful ac30.

    i'd take that to a tech and have it looked over.
     
  3. guiltless

    guiltless Member

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  4. kirk95

    kirk95 Jazz Lines You Can Use in the Blues Silver Supporting Member

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    I removed the right 2 tubes...lost the the Vib-Trem Channel.. and the Buzz.

    Still would feel better if someone would verify tube layout.

    Here's what was in there....

    [​IMG]
     
  5. 229someday

    229someday Member

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    Found this on Plexi Palace in the Vox section. Can't vouch for it : Starting near the big GZ34 rectifier tube: Phase Inverter - 12ax7 (ECC83), Brilliant & Normal front end - 12ax7, Vib/Trem Modulator - 12au7 (ECC82), Vib/Trem Oscillator - 12ax7, Vib/Trem front end - 12ax7
     
  6. fab58

    fab58 Member

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    If I remember correctly, as you look at the pre-amp tubes from the back, the first three on the left are in the VIB/Trem circuit. The middle one should be a 12au7. The 4th from the left is the normal and brilliant channel and the far right is the Phase Inverter.

    Here it is from left to right:

    V7 VIB/TREMOLO in (ECC83/12AX7)
    v9 OSCILLATION (ECC83/12AX7))
    V8 MODULATION (12AU7)
    V1 BRIGHT/NORM INPUT (ECC83/12AX7)
    V2 PHASE INVERTER (ECC83/12AX7)

    The rectifier is a GZ34 and the 4 Power amp tubes are EL84.
     
  7. pdf64

    pdf64 Member

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    Pinnacle are often relabelled Mullard or some other British Valve Association manufacturer.
     
  8. TheAmpNerd

    TheAmpNerd Member

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    That is a whole lotta fun in that amp.
     
  9. Red House

    Red House Silver Supporting Member

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    Firstly, beautiful amp!
    :beer

    Be careful when handling the tubes so that you don't rub the markings off of them.

    Again, awesome amp!
     
  10. TheAmpNerd

    TheAmpNerd Member

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    Yeah, your memory is pretty good, especially in dealing with
    the definitive British amp. The tube numbering scheme would
    make even Spock cringe though. I'll post a real treat for you
    over on my thread.
     

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