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(Alto) Bb Attachment Length

Posted: Sat May 12, 2018 9:36 am
by Matt K
Anybody have an alto they can give the approximate length for their Bb attachment tubing?

Re: (Alto) Bb Attachment Length

Posted: Sat May 12, 2018 9:51 am
by Neo Bri
To jump on this, isn't there something like a 6% increase in the length of a tube to get another half-step? So you should be able to figure it out that way. I've been trying to remember what the exact percentage is.

Re: (Alto) Bb Attachment Length

Posted: Sat May 12, 2018 6:44 pm
by timothy42b
Well, a Bb trombone is 9 feet, an alto 6 feet, so..................3 feet of tube?

That means you could make a Bb tenor/alto trombone just by making a straight short trombone with a really curved bell section tubing. No valve, just continuous looped tubing in the gooseneck.

It would fit in a really small case and be great in a pit or other short space.

Re: (Alto) Bb Attachment Length

Posted: Sat May 12, 2018 7:25 pm
by elmsandr
Bb in the neighborhood of 108-110”, verify with any tenor you have handy. Eb in the neighborhood of 84”. Do a little subtraction...

Or, figure out your own Eb length and use the 12th root of 2 to add each half step on a chart in excel.

Make it log the first time and trim down the legs of the tuning slide. Just have to not get too fancy with the wrap so that you have nothing to trim.

Good luck,
Andy

Re: (Alto) Bb Attachment Length

Posted: Sun May 13, 2018 8:31 am
by Matt K
Thanks all! Can't believe I didn't think to check the length of a Bb instrument. D'oh!

Re: (Alto) Bb Attachment Length

Posted: Sun May 13, 2018 9:01 am
by heinzgries
timothy42b wrote:
Sat May 12, 2018 6:44 pm
Well, a Bb trombone is 9 feet, an alto 6 feet, so..................3 feet of tube?

That means you could make a Bb tenor/alto trombone just by making a straight short trombone with a really curved bell section tubing. No valve, just continuous looped tubing in the gooseneck.

It would fit in a really small case and be great in a pit or other short space.
I have build one with Photoshop :wink:
Its my alto with a tunngslide to Bb. But it has max. a 6th position.

Image
https://i.imgur.com/83xba5q.jpg

Re: (Alto) Bb Attachment Length

Posted: Sun May 13, 2018 9:07 am
by Matt K
That's seriously cool! Is that the horn that is largely Bach 36 parts (or the slide perhaps?) or am I misremembering?

The horn I want to do this to is a Wessex 525/547. If I'm measuring correctly, I can still fit it in my Cronkhite alto gig bag when it's all said and done. Will be a super compact horn for sure. The screwbell thread is potentially for this horn. It has a super small bell and a distinct alto sound... wondering if I get an option for a bigger flare if it'll make it sound more tenory. Of course, that come after the Bb attachment though. I suspect putting it in Bb will go a long way towards giving me maybe a little bit of both. Although my Conn 36H certainly sounded like an alto on both sides of the horn, at least to me. So maybe not!

Re: (Alto) Bb Attachment Length

Posted: Sun May 13, 2018 10:54 am
by heinzgries
Matt K wrote:
Sun May 13, 2018 9:07 am
That's seriously cool! Is that the horn that is largely Bach 36 parts (or the slide perhaps?) or am I misremembering?
You remember right. Its a large Helmut Voigt alto with a short 36 Bach slide. This "german/american friendship"
works real fine.

Re: (Alto) Bb Attachment Length

Posted: Wed Jun 13, 2018 2:52 am
by Jgittleson
I made an A valve on an alto, all i did was measure how far i move the slide to get from Eb to A, and that was the wrap length, pretty straight forward.