(Alto) Bb Attachment Length

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Matt_K
Posts: 4809
Joined: Mar 21, 2018

by Matt_K »

Anybody have an alto they can give the approximate length for their Bb attachment tubing?
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Neo_Bri
Posts: 1342
Joined: Mar 21, 2018

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.
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timothy42b
Posts: 1812
Joined: Mar 27, 2018

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.
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elmsandr
Posts: 1373
Joined: Mar 23, 2018

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
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Matt_K
Posts: 4809
Joined: Mar 21, 2018

by Matt_K »

Thanks all! Can't believe I didn't think to check the length of a Bb instrument. D'oh!
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heinzgries
Posts: 250
Joined: Apr 24, 2018

by heinzgries »

[quote="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.[/quote]

I have build one with Photoshop <span class="emoji" title=":wink:">😉</span>

Its my alto with a tunngslide to Bb. But it has max. a 6th position.

User image

<IMGUR id="83xba5q">https://i.imgur.com/83xba5q.jpg</IMGUR>
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Matt_K
Posts: 4809
Joined: Mar 21, 2018

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!
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heinzgries
Posts: 250
Joined: Apr 24, 2018

by heinzgries »

[quote="Matt K"]That's seriously cool! Is that the horn that is largely Bach 36 parts (or the slide perhaps?) or am I misremembering?[/quote]
You remember right. Its a large Helmut Voigt alto with a short 36 Bach slide. This "german/american friendship"

works real fine.
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Jgittleson
Posts: 255
Joined: Jun 13, 2018

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.