Results 1 to 8 of 8

Thread: bore sizes

  1. #1

    bore sizes

    So I've had my new Besson Prestige 2052 about a week now, and I still have a borrowed Willson 2900 here, I was curious about bore sizes, so I pulled out my (plastic) digital calipers. Here's what I got.



    2nd valve slide

    Besson .590

    Willson .590



    Compensating loop, 3rd valve slide

    Besson .630

    Willson .630



    4th valve slide

    Besson .650/.650

    Willson .630/.670



    I verified by trying the slides on each other. Other than being different lengths, the 2nd valve and compensating valve slides are interchangeable between the two instruments with a good fit. The smaller leg of the willson 4th valve tuning slide fits perfectly into the compensating tuning slide on the back.



    Willson quotes their bore as being .590/.630, Besson has historically quoted their bore as being .580/.640, but has recently switched their literature just to say .590.

    Anyways, I had always assumed Willsons to be much bigger bore than Bessons based on the quoted specs, but it's really not true. They are exactly the same until the compensating loop comes out of the 3rd valve at which point the besson starts getting bigger first whereas the willson stays cylindrical until the bow of the tuning slide at which point it gets a little bigger than the besson does in the tuning slide. Their average size is the same.

    I also had an interesting time measuring my 4-valve besson 2056 baritone against a friend's besson 955 3-valve compensating baritone recently. Besson quotes the 2056 as being .540 bore and the 955 as being .916. That sounded wrong to me since they play so similarly and have very similar sounds, but that's a huge difference. Well, it's true. The 2056 is indeed .540 on both the 2nd valve slide and the 3rd valve compensating loop slide and the 2nd valve slide on the .955 is indeed .516. The main tuning slides are identical, though, and it looks like the branches and bell from the tuning slide on out are identical. My guess is that they found the smaller bore didn't work so well with the extended low range, and found a way to compensate for the bore with the leadpipe tapers to make them sound and feel the same.

    So anyways, this is all very nerdy, but my point was that you can't really compare the bore sizes that manufacturers quote in their literature or on their web site, and even if you can directly compare them, it doesn't necessarily mean anything about how the instrument actually plays!

    --
    Barry

  2. #2

    bore sizes

    To wit, miraphone 5050 is listed on their website as being .610/.638 (once I do the mm to inches conversion). I'd be interested to know if that .638 is the compensating loop on the back of the valves bore or of it is the 4th valve tuning slide bore, the way that besson and willson quote it. Certainly the .610 is much bigger than the .590 besson/willson use -- but the .638 could either mean the 5050 is a more cylindrical instrument, at least within the 4th valve section, or they could have taken the smaller measurement.

    Sterling's web site actually lists three bore sizes, for "1st 2nd 3rd", compensating, and 4th. Their measurements are .590,.630,.670 -- Sounds like the same as the willson, but it'd be interesting to see how they actually did it.

    Anyone have any digital calipers and want to get some data on their euphoniums?

    --
    Barry

  3. #3

    bore sizes

    Originally posted by: bbocanerTo wit, miraphone 5050 is listed on their website as being .610/.638 (once I do the mm to inches conversion). I'd be interested to know if that .638 is the compensating loop on the back of the valves bore or of it is the 4th valve tuning slide bore, the way that besson and willson quote it. Certainly the .610 is much bigger than the .590 besson/willson use -- but the .638 could either mean the 5050 is a more cylindrical instrument, at least within the 4th valve section, or they could have taken the smaller measurement.


    Quick measurement of my 5050 show 0.610" at 2nd valve, 0.638" at 4th valve and in comp loop.Don Winston

  4. #4

    bore sizes

    Interesting! That would seem to suggest that even though the 5050's tubing through the valves is larger than a lot of the other instruments, it's probably slightly smaller than Besson or Willson at the beginning of the main tuning slide - because there can't be a big jump from the end of the 4th valve tuning slide to the beginning of the main tuning slide.

    Thanks, Don!

    --
    Barry

  5. #5
    Join Date
    Jan 2006
    Location
    West Palm Beach, FL
    Posts
    3,853

    bore sizes

    Barry,

    Not sure if you're interested in the measured bore size of Yamaha comps. The specs are listed as the same for 642 and 641 (0.591-0.661"). Below is what I actually measured on my 641 with my digital calipers:

    2nd valve slide:
    .591

    Comp Loop 3rd valve slide:
    .630

    4th valve slide:
    .630 / .670



    We had a discussion some time ago about which model horns had a tapered 4th valve slide. If I remember correctly it was only the Besson and Sterling that DID NOT have a tapered 4th slide. But... from what "djwpe" posted, looks like the Miraphone 5050 does not have a tapered 4th valve slide either.
    Rick Floyd
    Miraphone 5050 - Warburton BJ / RF mpc
    YEP-641S (recently sold)
    Doug Elliott - 102 rim; I-cup; I-9 shank


    "Always play with a good tone, never louder than lovely, never softer than supported." - author unknown.
    Symphonic Band of the Palm Beaches
    El Cumbanchero (Raphael Hernandez, arr. Naohiro Iwai)
    Chorale and Shaker Dance
    (John Zdechlik)

  6. #6

    bore sizes

    Thanks, Rick. Interesting stuff!

    --
    Barry

  7. #7

    bore sizes

    Originally posted by: RickFWe had a discussion some time ago about which model horns had a tapered 4th valve slide. If I remember correctly it was only the Besson and Sterling that DID NOT have a tapered 4th slide. But... from what "djwpe" posted, looks like the Miraphone 5050 does not have a tapered 4th valve slide either.
    I've been meaning to get back and clarify for a couple of days. The 5050 DOES have a tapered 4th slide. I will put a more comprehensive set of measurements up sometime later in the week.Don Winston

  8. #8
    just wanted to add to this that I have had a chance to measure a MODERN Besson 955 against the Besson 2056 and both are .540. They must have changed the entire line over to .540 when they restarted 955 production in 2010(ish?).

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •