PVA= Voodoo??

Discussion in 'Trumpet Discussion' started by dizforprez, Aug 8, 2004.

  1. dizforprez

    dizforprez Forte User

    1,097
    1
    Nov 2, 2003
    I admit I am among the most skeptical people out there when it comes to “magic†solutions to problems on the horn but this weekend was an eye opener. On Saturday I had the pleasure to meet Joel ( aka riff dog here on TM) and he was kind enough to let me blow a few notes on his stomvi elite piccolo so he and I could do a little side by side comparison of our two piccolo trumpets.

    The results? His stomvi with a PVA blew better than my stomvi with a Blackburn pipe. In every way you could imagine his horn came out on top. Now not that mine was a dog, but I dare say his horn made playing piccolo a pleasure.

    Time to pinch some pennies :wink: thanks joel!
     
  2. MUSICandCHARACTER

    MUSICandCHARACTER Forte User

    1,140
    2
    Jan 31, 2004
    Newburgh, Indiana
    Interesting. Did his have a Blackburn pipe? I know that PVA is all the rage, and that is part of the "tweaking" you get from a Wild Thing. But shouldn't a well-built horn have a valve alignment? It sounds like buying a new car and taking it to a independent tire shop to have the wheels aligned. I would be a bit more than upset.

    Now on a used horn, it seems to make more sense. After some years, the valves may need to be aligned (like perhaps a used car).

    The reason I asked about the leadpipe is that I believe you must really match a mouthpiece to your embouchure and to the horn -- including the leadpipe. Using your mouthpieces may not be right for his piccolo. Using his mouthpieces may not be right for your embouchure.

    I guess the only way to know is to have a PVA done to yours. That is what we live for -- to play better. A piccolo is so hard to play in tune that any help might be quite useful.

    Jim
     
  3. W Scott

    W Scott Piano User

    488
    4
    Dec 8, 2003
    Carson City, NV.
    My horn will be back from the Brass Bow with a PVA by the end of this week. I'll let you guys know how it turns out. The procedure is not just making sure that the valves are lined up. They also replace the felts, corks and anything else that can degrade with something called Delrin (sp?) which is inert and won't change with time.

    Bill
     
  4. pangaea

    pangaea Pianissimo User

    94
    0
    Nov 10, 2003
    Here we go again...

    No, a PVA is not voodoo. I consider the cryo treatment to be questionable, and science backs that position up. But a PVA yields a measureable result.

    I agree that a new pro horn SHOULD have its valves perfectly aligned, but that's patently not the case. A Schilke, my favorite trumpet and perhaps one of the top handful of horns anywhere, does NOT come with perfectly aligned valves.

    Why they do not come w/ a PVA is a matter for discussion.
     
  5. riffdawg2000

    riffdawg2000 Pianissimo User

    59
    0
    Jan 9, 2004
    Atlanta, GA
    Not a problem Jason! Glad you enjoyed it!

    Yea, I am a firm advocate for valve alignments. At least the ones that Wayne Tanabe does at the Brass Bow. I am sure that Bob Reeves and K.O. also do a good job.

    My story ... I got my Stomvi Elite piccolos almost a year ago. Prior to the PVA, it was a good little piccolo. Intonation was decent and it played very well ... but I knew that the third valve must not be aligned right because you could FEEL the interruption in the airflow when it was depressed. So, my teacher recommended a PVA ... and off the horn went. It left, a solid and good piccolo, IMO it came back an outstanding piccolo.

    Well ... back in July, I sent off my 1993 Bach Strad CL180S to the same PVA ... once again ... it left being a 'good' horn, now it's an outstanding horn (IMHO)

    The 1992 Bach 180S is next ... scheduled for September ...

    Anybody that is interested - just call and talk to Wayne or 'Ken' at the Brass Bow, they will explain and schedule a specific time for you to have the work done!

    IMHO, it is WELL worth the $130-$175 you pay!

    Regards,
    Joel
     
  6. tom turner

    tom turner Mezzo Forte User

    779
    11
    Oct 25, 2003
    Georgia, USA
    Hi,

    There's no vodoo science involved in eliminating the ACCUMULATED tolerance variations found within an assembled valve. Once those tolerance flaws are eliminated, both vertically and rotationally, any instrument will play better!

    Bob Reeves says it so well on his website. I'll post the link below, which also shows a photo of 5 of the six valve parts disassembled.

    [However, he did NOT unsolder the valve spring barrel from the top of the valve. Sometimes even a valve itself is too short or tall. Same with the valve spring barrel . . . or the valve spring barrel can be soldered onto the top of the valve a degree or two off, rotationally (causing rotational mis-aliginment). Then sometimes even the three valve BODIES can be assembled a little off tolerance-wise . . . or have the valve guide slot cut a little off . . . etc.]
    ____________________________
    Here's what Bob said, at link http://www.bobreeves.com/products/valvealignment/truth/index.htm :

    "All horns suffer from what is known as accumulated tolerances. Accumulated tolerances result from the way all instruments are built: Each part of the trumpet is made to a certain specification, and each specification is given a designated tolerance (typically .005").

    For example, let’s say the dimension for a given valve button is .250" high (1/4 Inch). With a tolerance factor of plus or minus .005" the machinist can make a button anywhere from .245" to .255" and it will still pass inspection.

    Assume the person who built your horn made the valve button .255" (.005" big). Then let’s say the valve stem was made .003" big, the spring barrel .002" short, the valve cap exactly to specification, and so on...

    By the time the horn is assembled, it is easy to see how the accumulated tolerances can add up to .020", .030", .040", or more!" - Bob Reeves
    __________________________________

    Probably about .030 is the norm on pro horns. Going into the local guitar shop to purchase a valve "alignment" set of felts will NOT correct for an accumulated +/- of .030" on a SPECIFIC valve!

    Plus, not all out of spec problems can be solved with felt! Sometimes a valve spring barrel must be unsoldered from the valve, then realigned PERFECTLY to get the ports lined up rotationally. Sometimes a valve spring barrel must be shortened . . . or a valve stem . . . etc.

    It is truly amazing what life can be put into an assembly line horn when a perfectionist like Wayne Tanabe, Bob Reeves, or Flip Oakes gets hold of a stock horn and fixes all the accumulated imperfections!

    dizforprez . . . I'm glad you got to find this out!!!

    All any decent player has to do is PLAY the horns to tell the difference . . . and that . . . dear friends . . . ain't vodoo science either!

    Sincerely,

    Tom TUrner
    "
     
  7. djm6701

    djm6701 Pianissimo User

    My Benge 3x was so far out on the downstroke that Ron Partch had to mill down the tops of the valve casing caps to allow the valve to go down far enough to be in alignment, but the horn came back playing sooooo much better!
     
  8. dizforprez

    dizforprez Forte User

    1,097
    1
    Nov 2, 2003
    It would make sense to me that a new horn should come with a valve alignment but it would seem that it just isn’t the case. Playing his piccolo this weekend and my teachers old C trumpet that has also had a PVA has finally sold me on the idea that this is really worth the effort to have it done.

    the leadpipe issue is a good point but in this case since we had the "same" horn so i think it was a good test of the PVA. I didn’t have any problems with the leadpipe mpc match up, because I have played a stomvi with and with out a Blackburn pipe before( i only got the pipe last month). My laskey picc mpc worked just as well with his horn as it did with mine.

    anyway..i give it the thumbs up for all of you out there if you are up for trying it.
     
  9. riffdawg2000

    riffdawg2000 Pianissimo User

    59
    0
    Jan 9, 2004
    Atlanta, GA
    What can I say? I like my Bachs. And I guess the Yamaha's don't impress me enough to spend the time selling my Bachs, and buying new (or slightly used) Yamahas.

    If I knew a little over a year ago when I started my 'comeback', what I know now ... I might have started out with Yamahas ...
     
  10. MUSICandCHARACTER

    MUSICandCHARACTER Forte User

    1,140
    2
    Jan 31, 2004
    Newburgh, Indiana
    Tom,

    I thought I posted this before, but perhaps I didn't hit the submit button. I can understand how cumulative problems can add up. But they don't always add UP. For example, if the valve button is off .005 and then the valve stem is off .003. It might be the other direction and thus make the cumulative off by only .002. In fact, over the long haul, this would be just as likely. The statistically principal of the central limits theorem would suggest that with enough samples, a regression to the mean (average) is expected (too many years of teaching graduate statistics). Again, the central limits theorem does not directly say this, but after putting it into action it predicts the outcome.

    So on a new horn, the cumulative tolerances would be MORE LIKELY to be closer to zero than the other extreme. Again, I would be upset if I paid for a new horn and a PVA was required.

    The other point is what you said above. Flip can be truly amazing at bringing a stock horn "to life" by making adjustments. I have seen you and Flip post that Flip puts hours into a horn to tune it (tweak it) before it ships. A PVA is part of that tweaking if I understand it right. You talked about how a PVA sometimes requires soldering and de-soldering to get the rotational tolerances right. Does that mean that Flip will take a new Wild Thing from Kanstul and actually de-solder and solder it?

    Knowing what I know about manufacturing processes and statistics, I cannot imagine a horn being out by that much in a cumulative fashion. All the errors would have to be in one direction.

    Jim
     

Share This Page