Circuit for preamplifier with 12AX7!

Discussion in 'The Projects Forum' started by Petrus Armagedon, Jul 1, 2011.

  1. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    Hello!
    A friend lent scheme and said it was great!;)
    Because I want to Make this preamp with ECC83 (12AX7) seek opinion or comment about it?:rolleyes:
    I will be very grateful
     
    Last edited: Jul 1, 2011
  2. SgtWookie

    Expert

    Jul 17, 2007
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    The 12AX7's were great tubes/valves. Many audiophiles still prefer the "warm sound" of tubes/valves over transistorized amplifiers.

    However, without seeing your schematic, it will be very hard to comment on it.
     
  3. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
    24
    0
    Hello!
    A friend lent scheme and said it was great!;)
    Because I want to Make this preamp with ECC83 (12AX7) seek opinion or comment about it?:rolleyes:
    I will be very grateful
     
    Last edited: Jul 3, 2011
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    The components in the schematic do not have any values, other than the tube/valve itself and the 250v B+. It would be difficult to evaluate the performance of such a circuit.
     
  5. #12

    Expert

    Nov 30, 2010
    16,284
    6,797
    Much like wookie said, The basic layout is valid except nothing has a value labeled. The values of the resistors and capacitors can make or break this circuit. That completely ruins its value as a workable circuit. Your "friend" didn't give you anything useful.
     
  6. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
    24
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    Here the value of components:
     
    Last edited: Jul 3, 2011
  7. SgtWookie

    Expert

    Jul 17, 2007
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    Wait a moment - in this thread:
    http://forum.allaboutcircuits.com/showthread.php?t=56430
    you have mentioned wanting to use a 12AU7/ECC82 instead of a 12AX7/ECC83

    The 12AX7/ECC83 is a high-gain (Av~=100) tube/valve, where the 12AU7/ECC82 is a medium-gain (Av~=17-20) tube/valve.

    Were you intending to adapt the schematic and components used for the medium-gain tube/valve?
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    12AU7 specifications: http://www.nj7p.org/Tube4.php?tube=12AU7
    12AX7 specifications: http://www.nj7p.org/Tube4.php?tube=12AX7

    [eta]
    Here's a preamp project using 12AU7 tubes that a fellow built:
    http://www.shine7.com/audio/12au7_pre.htm

    It's based on the 12AX7 preamp that he also built:
    http://www.shine7.com/audio/12ax7_pre.htm

    Since that person has already constructed two completed projects and published the results, I'd suggest you follow their design closely if you wish to obtain similar results.
     
  9. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    I begged you to offer your scheme (circuit) with ECC88 or ECC82, and to decide on which scheme to create preamplifier?!
    thanks
     
  10. SgtWookie

    Expert

    Jul 17, 2007
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    See my reply #8; click on the links that I posted for the preamp projects. I think they are exactly what you need.
     
  11. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
    24
    0
    Very good design!
    Where to find power supply for this scheme preamolifier?:confused:
    thanks
     
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