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New Tubes?

Discussion in 'Pro Audio Equipment' started by eddies880, May 27, 2005.

  1. eddies880

    eddies880 Guest

    As Ive stated before,I own a used 2000e and was considering replacing the tubes,I was able to locate a pair of J.J. ECC 81 12AT7s(new).
    Im getting ready to lay vocal tracks,
    1. Is there anything I should look out for as far as replacing the
    the tubes
    2. How many hrs of use on the Seb before they brk in?
  2. mikE@THECAVE

    mikE@THECAVE Guest

    yea i'd get me a Mullard and an Amperex and some others telefunken
  3. eddies880

    eddies880 Guest

    Them-ter Mullards arent cheap$$
  4. Sebatron

    Sebatron Well-Known Member

    Dec 22, 2002
    The boogey man..... Elvis Presley ......
    No seriously... ,, look out for microphony ..... tap the tube with your fingernail and listen to the sound. Does it ring?
    If so , it may be microphonic.
    Avoid Sovtek by all means.

    4 hours minimum.
    10 hours is good for NOS.
    20+ hours should settle them in well if they are brand new.

  5. eddies880

    eddies880 Guest

    If you wouldnt mind,please explain the term "microphony"---is it some source of unwanted tone?
  6. Sebatron

    Sebatron Well-Known Member

    Dec 22, 2002
    sometimes valves ( due to variances in construction) exhibit a tendancy to be sensitive to sounds and vibration.Sometimes it's so bad they can feedback on themselves during high gain demands.
    Tapping the valve is one way to check for microphony.
    Usually the J.J valves don't have many problems.


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