High End preamplifier wit ECC83 (12AX7)!

Discussion in 'The Projects Forum' started by Petrus Armagedon, Jul 3, 2011.

  1. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    Hi
    Here I started working preamplifier with ECC83!
    For starters here are wooden boxes
     
    Last edited: Jul 3, 2011
  2. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    Hello all!
    Something i recently worked and managed to create this Tube Premplifier with ECC83 (12AX7)?;):)
    View Post: Circuit for preamplifier with 12AX7!
    Here's my work looks like this:
     
    Last edited: Jul 6, 2011
  3. MrChips

    Moderator

    Oct 2, 2009
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    Cool!
    One of my first projects I built when I was 16 was a darkroom timer using a 6SN7.
     
  4. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    "OK"!???
    Human stupidity is infinite,..... and the univers?
    For I am not sure unvers,....??!
    Einstein
    Cheers !
     
    Last edited: Jul 6, 2011
  5. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    Hi
    Not to be all the way,.... this is how the second harmonic is!;)
    And the frequency response is here!;):)
    thanks
     
  6. Audioguru

    New Member

    Dec 20, 2007
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    The very old tubes preamp has pretty high distortion. The second harmonic is a 0.5% distortion and the third harmonic is at 0.1%. The distortion will get worse as the tube wears out.

    Why is there a 5dB peak at 30kHz? Why does the circuit produce 50Hz, 100Hz and 200Hz hum?

    If you use an audio opamp (OPA2134 dual or better) then the total distortion will be only 0.00008%. The distortion will not get worse. The response will be absolutely flat up to about 100kHz. There will not be any hum.
     
  7. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    If everyone got rid of audio distortion then Rock music would sound HORRIBLE.

    :)
     
  8. Audioguru

    New Member

    Dec 20, 2007
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    A lot of rock music sounds HORRIBLE to people who weren't deafened by its terrible distortion. Deaf people can't hear the high frequencies where the distortion is located.
     
  9. CDRIVE

    Senior Member

    Jul 1, 2008
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    Why a response like this? :mad:
     
  10. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    Spoken like an honorable man who has never played a rock guitar riff with the amp turned up to the 'mythical' 11.

    :)
     
  11. #12

    Expert

    Nov 30, 2010
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    A lot of old people don't like rock and roll, just some of them get cranky about it. :p
     
  12. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    Distortion is the second harmnic 0.78% at 2kHz! To get the right one Valve/Tube sound!!;):) At 30kHz the elevation of 5dB due to losses in the cables?
    Noise (hum) at 50Hz, 100Hz and etc so is the equipment (from the computer sound card "Creative Sound Blaster Audigy SE").
    Cheers ;)
     
    Last edited by a moderator: Jul 8, 2011
  13. Audioguru

    New Member

    Dec 20, 2007
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    No.
    The input is 1kHz so the second harmonic is at 2kHz. It is shown at 46dB down so its is -6dB (half) of -40dB (1%) which is 0.5%.
    I know that vacuum tubes (valves) produced high even-order distortion that some people like.

    No.
    Capacitance of cables will cut high frequencies, not cause one frequency to be boosted. I don't know why until I see the schematic.

    Hum is usually from using AC for the filament. Some people use filtered DC for the filament to eliminate hum in one of these very old circuits.
     
  14. Petrus Armagedon

    Thread Starter New Member

    Jul 1, 2011
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    Audioguru, your remarks somewhat wrong!?
    Power the filaments tubes with a well filtered DC-voltage (2x6,3Vdc) - noise (hum) is >88dB below!! (see measuraments with CLIO!) ;):eek: Second harmonic (even harmonics) gives one a real warm sound that Valve is great for introducing!! ;):)
    Cheers

    P.S.
    Here are the measurements from profi device CLIO!
    Figure A and Figure C.
     
    Last edited: Jul 8, 2011
  15. Audioguru

    New Member

    Dec 20, 2007
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    I disagree with you because my first preamp and power amp used vacuum tubes about 48 years ago and my newest solid state amplifiers have much less distortion that does not get worse which happened when the vacuum tubes wore out.

    An amplifier is not supposed to produce any audible distortion. 1% second harmonic or more is terrible. Listen to a live orchestra or singer and there is NO distortion just like a modern amplifier.

    Vacuum tube power amplifiers have an output transformer that rolls-off low and high frequencies. It adds distortion. The output impedance is up to 1000 times more than a modern solid state amplifier so the resonances of speakers are not well damped.
     
  16. #12

    Expert

    Nov 30, 2010
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    Dear AG,

    A HIGH FIDELITY amplifier is not supposed to produce any audible distortion. A transistor amplifier for guitars produces so little distortion that it sounds terrible to the musicians. After they are done performing, you are welcome to listen to it with a hi-fi amp. On stage, you couldn't sell a no-distortion amplifier for a penny a watt.

    The world has more than one kind of people in it, and judging by the billions of dollars spent purchasing music from distorted amplifiers, I think there are several people that disagree with you. I hope you don't feel as bad as you sound when you are grousing about distortion. I wouldn't want this issue to affect you health.

    With all respect, #12
     
  17. CDRIVE

    Senior Member

    Jul 1, 2008
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    Personally, I'm glad that there's young folk out there that still appreciate the old girls. This argument is about as pointless as those who like liver and those who would rather eat road pizza!
     
  18. Audioguru

    New Member

    Dec 20, 2007
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    I have also noticed that speakers and enclosures for them made for electric guitars are also horrible.
     
  19. CDRIVE

    Senior Member

    Jul 1, 2008
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    AG, I don't think that you'll ever have to worry about being dethroned as AAC's most contrary, cranky and argumentative (I may miss some adjectives) member. :D I thought Canadians, with all that clean air, were generally mellow? You gotta get out more.... Maybe fishing?:rolleyes:
     
  20. Audioguru

    New Member

    Dec 20, 2007
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    I live in a suburb of Toronto in southern Canada. Most "clean" air comes from the polluting coal burning electricity stations in Illinois (USA). Near me they destroyed the last coal burning electricity station a few years ago.

    I am not mellow because I get out too much. I see too many new immigrants who are scary-looking.
     
    #12 likes this.
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