Valve alignment

Discussion in 'Trumpet Discussion' started by nordlandstrompet, Aug 6, 2009.

  1. nordlandstrompet

    nordlandstrompet Forte User

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    Apr 5, 2008
    Norway
    “Valve alignment” is obviously meant to be a correction/adjustment of the ports/liners in the valves
    to obtain a smoothest possible transition between the valves and tubes/slides.

    When thinking about acoustics and standing waves, I am not sure that we actually talk
    about “smoothest possible transport of air” but I tend to think more like
    “smoothest possible transport of the standing wave”.

    As an example: I bought an old Couesnon flugel, which had an extremely
    “tight” resistance when I tried it with open fingerings.
    This “tightness” opened up when I pushed down the valves.
    The more valves pushed down, the more open sound.
    The short stroke of the valves made me suspicious, and when I took out the valves,
    there was three (3) felts under the cap. The misalignment was appr 3mm
    which covered 30-ish percent of the passage through the valves.
    Removed two of the felts, the valves came back to their original position
    again (95-ish%...)and the horn started to play again.

    So, what about this “smoothest possible transport of the standing wave theory”?
    My idea is that in this (my) case, the wave was disturbed (reflected?)
    by the extreme obstructions/surfaces it met on its way through the
    “acoustic area” in the horn.
    When the obstructions was removed, the wave could operate freely again.

    Just some philosophical poetry?
     
  2. rowuk

    rowuk Moderator Staff Member

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    Any change in the bore size moves the resonant nodes to a different place in the length of the wind instrument. Braces are usually placed to damp certain nodes. If we have dramatic out of alignment, it is possible that the "good vibes" are affected by the bracing, and the "bad vibes" get through and make the horn harder to play.
     
  3. oldlou

    oldlou Forte User

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    Many years ago at the York Band Instrument plant Gene Pilchuk discovered and did a GREAT DEAL of research on the relationship of a tuned stepped bore leadpipe to correct intonation problems in the trumpet. I was just a college kid at that time, but Genes leadpipe on my dads King Silvertone trumpet made false fingerings and on the fly slide adjustments a thing of the past. That old trumpet was a super fine horn, right from the factory, but became a much better horn immediately after the installation of Genes leadpipe. The concept of a tuned series of slight expansions in the leadpipe instead of a constant taper is all that this took.


    OLDLOU>>
     
  4. Bob Grier

    Bob Grier Forte User

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    When the ports in the pistons don't line up with the ports in the casings, they cause a disturbance in the air/sound column. It baffles the air if you will. This by degrees causes the horn to play stuffy and out of tune with itself
     

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