(Alto) Bb Attachment Length

[Matt K]

Anybody have an alto they can give the approximate length for their Bb attachment tubing?

[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.

[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.

[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

[Matt K]

Thanks all! Can't believe I didn't think to check the length of a Bb instrument. D'oh!

[heinzgries]

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

[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!

[heinzgries]

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.

[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.