c conversions

Discussion in 'Trumpet Repair and Modification' started by dcpritchett, Jun 29, 2015.

  1. dcpritchett

    dcpritchett Pianissimo User

    Jan 20, 2015
    Central FL
    I keep reading about Ambassador b flat conversions to C. Would the measurements of an Olds Custom Crafted C which is also .460 bore work on the Ambassador?
  2. SteveRicks

    SteveRicks Fortissimo User

    Aug 15, 2009
    So you mean take an Ambassador Bb and cut the slides down to a C? Personally, I would probably look for a C rather than trying a conversion unless you have a junker you are experimenting with. Most things are best the way originally designed. Anyway, looking forward to seeing others ideas.
  3. dcpritchett

    dcpritchett Pianissimo User

    Jan 20, 2015
    Central FL
    I own the c in question. I was looking at the conversions that are being advertised for uo to $700. Buy a good ambassador, convert and make money fr more horns.
  4. BrassBandMajor

    BrassBandMajor Fortissimo User

    Jan 13, 2015
    I know guy who is selling a Holton Collegiate horn cut down to C.
    Quite nice looking horn
  5. Vulgano Brother

    Vulgano Brother Moderator Staff Member

    Mar 23, 2006
    Parts Unknown
    If the slides are the same distance apart (the bows are the same) you can just measure off your C.
  6. rowuk

    rowuk Moderator Staff Member

    Jun 18, 2006
    You have an excellent question. This has been asked several times here and the answer is that it depends. For cylindrical tubing, the length determines the frequency. Conical or flared parts tune according to horn theory and irregular shapes resonate based on volume.

    In the case of cutting down a Bb, the length of the valve slides including the bow should be the same. Most designs have similar bell lengths, so the second place to cut is the leadpipe on both sides of the tuning slide. The problem with that is that a Bb leadpipe has the wrong proportions for being cut down. I would recommend getting a real C trumpet leadpipe like from Najoom, Malone, or from Yamaha (there are others but I haven't tried them). A real C leadpipe will improve intonation.

    That all being said, the ambassador is not that hot of an instrument and cutting it down will for sure be fun, but the C will be sluggish sounding and playing compared to a horn designed for C. You will have to experiment with braces until you get a fairly even response.
  7. PelicansRule

    PelicansRule Pianissimo User

    Feb 2, 2015
    Pittsburgh, PA
    Aw man, don't do that. Keep it original.
  8. trumpetsplus

    trumpetsplus Fortissimo User

    Jun 11, 2006
    South Salem, NY
    I have converted a few Ambassadors. They have all worked well, especially when I change the garrote bracing around the valve casings. As Rowuk suggests, he critical thing is to know how to modify the lead pipe.
  9. dcpritchett

    dcpritchett Pianissimo User

    Jan 20, 2015
    Central FL
    In other words, it will work, maybe. Your mileage may vary. I never really expected the conversion to be a really good C as the manufacturers seem to still have their own challenges (intonation) when they start from scratch. I think I will leave well enough alone and just enjoy my Custom Crafted. Thanks for the replies.
  10. Bochawa!!!

    Bochawa!!! Forte User

    Nov 4, 2007
    It is good to read one of these conversion threads that has sensible replies. So much, "If you attempt this you will unleash a pox upon the nation," bull sh** out there.

    Here's my first one I just finished . . .





    I listed it on eBay and it was purchased by John Hagstrom who plays for the Chicago Symphony. I certainly did not expect that. I was beside myself stressing about whether or not he would find it satisfactory. Here's what he said;

    "I once played on the C trumpet that Conn had made for Harry Glantz (by cutting down a Bb—it may have been a 2B or 22B), and yours plays better in tune!"

    PHEW!!! What a relief.

    Who knows? Maybe I just got lucky, but I am just about to start another one. It is a 1921 threshold 2B New Wonder/4B Symphony that is in way better shape than the 2B was. I'll post my progress in this thread, if it's alright with you guys.

Share This Page