TromboneChat

Hi Chatters,

I've got a Bach 36BO. I'm planning on cutting the F-attachment tuning slide to G. How much tubing to I need to cut from it to make the magic happen? Is there a formula I can use to remove 2 half-steps of tubing from the attachment? If it's longer than the available length of the tuning slide itself, I'll need to figure out how to reduce the length of the attachment itself, which may actually be a better plan.

Thoughts?

A Bb horn is approx 108 inches tube length, for every 1/2 step higher, divide by 1.0595 (twelfth root of 2)
For every 1/2 step lower, multiply by 1.0595, so that:
Eb=80.9 (alto length)
D=85.7
Db=90.8
C=96
B=102
Bb=108 (tenor length)
A=114.4
Ab=121.2
G=128.4
Gb=136
F=144.2 (F contrabass length)
E=152.7
Eb=161.8
D=171.4

so F to G = 144.2 - 128.4 = 15.8 inches removed (7.9 inches per leg)

Exactly what I was hoping for. Thanks! I hope this helps someone in the future, too.

Why is g better?

/Tom

imsevimse wrote: ↑Tue Aug 07, 2018 1:12 pm Why is g better?

/Tom

All 4th position notes now in first position... Still a C and B, but closer to the middle of the slide. Only notes lost are pretty rare anyway, low Db and C.

imsevimse wrote: ↑Tue Aug 07, 2018 1:12 pm Why is g better?

/Tom

So you can play G whizz.

I can see the point when going from an f to a d on fourth and back. That's a common pattern. That will be easier on rhe g-valve as well as F-Db and back were you often need to play the f on sixth position. You loose the E. Maybe not very common on fast passages on a tenor but you also loose the Bb on v3. That's worse. Interesting concept!

Are there any factory made horns with g-valve?

/Tom

All the botique makers have it as a standard option on their basses for the second valve, so technically yes. THey'll also build you oe on request without too much difficult though I don't know if I've ever seen one that wasn't customized aftermarket.

Just make it independent and you get the best of both worlds, or dependent Bb/G/F!!

Yes, I know the inline basses are like that. I mostly play dependant so I have not experimented much with that tuning.

On a tenor the valve is most used for C, B, Bb, F and E. If you go lower you are in the bass register and if you think of it the notes below E are mostly used when you play third in a trombone trio (usually written for a bass trombone) or some solo litterature that wants you to play at least a low C. In most advanced big band charts the third part could be a lot easier with a g-valve.

/Tom

If you do this (which I've thought was a very interesting idea for some time), first do the math, and then approach the surgery as a sequence of steps. Do not try to "get there in a single cut". The chance of overshooting is high, and then you'll be real sorry. And at each cut, play on it for a while -- like a week or so. Don't try to proceed too quickly. Do the test playing in several different conditions (temperature, humidity, small room, large concert hall, etc.). Slow and steady wins the race.

Having cut a similar section (42BO), try this... Get a closed wrap tuning slide. Rotate the "S" tube a little and just cut the 90 just enough so that the tuning slide span matches the new tuning slide radius. You will have to trim the length on the closed wrap tuning slide and slightly trim the nickel outers to get an in tune G. But, if you just start with the 90, that is the only part you are modifying to make it really close.

FWIW, I like my G attachments to be capable of being adjusted from 20.5-22" in length. I measured mine in tune at ~21" with a piece of string. I'd check it again, but I don't own it anymore.
Cheers,
Andy

extremely close to the measurements given above

remember, only include measure ONE of the 2 ports inside the rotary valve for purposes of the cumulative length of the section. The other port's length is "borrowed" from the overall length of the horn.

And, also remember, its always better to be sharp, so don't worry about cutting a little too much. a little.

imsevimse wrote: ↑Tue Aug 07, 2018 3:21 pm I can see the point when going from an f to a d on fourth and back. That's a common pattern. That will be easier on rhe g-valve as well as F-Db and back were you often need to play the f on sixth position. You loose the E. Maybe not very common on fast passages on a tenor but you also loose the Bb on v3. That's worse. Interesting concept!

Are there any factory made horns with g-valve?

/Tom

One of the regular contributors on TTF had pictures of reconfiguring his King just by resetting tuning slides. Don't know if that's still possible on the Kings.

Holton also sold a tenor trombone with G tuning.

Do you recall which model Holton tenor trombone has the 'G' attachment please?

TR658 was the model number. Found one here
http://www.horn-u-copia.net/show.php?se ... 3D"Holton"

/Tom

Thank you Tom!

imsevimse wrote: ↑Tue Aug 07, 2018 1:12 pm Why is g better?

/Tom

Here's a blast from the past:

https://patents.google.com/patent/US5435222

There was quite a long discussion about the advantages of the G attachment (aka minor third attachment) on the old Forum, and I guess on the trombone-l that preceded it. Proponents were Alan Charlesworth and B. P. Leonard. I didn't find anything searching the archives.

It made a lot of sense to me, for technical options in the medium range.

So if I wanted one of my valves in the key of D instead of G-flat, how long would it have to be?

One of the regular contributors on TTF had pictures of reconfiguring his King just by resetting tuning slides. Don't know if that's still possible on the Kings.
[/quote]

Not with the couple of King's I've seen lately. Conn-Selmer has changes the configuration of the valve section so that it will take quite a bit of slicing & dicing to get this interchangeability possible.

And thinking a bit more deeply into the project I recently had, I'm vaguely remembering that it was not possible to make it flip from G to F again. But I may be wrong.

I'll see if I can contact the customer and find out.


Eric

Rrova wrote: ↑Fri Aug 17, 2018 6:38 am So if I wanted one of my valves in the key of D instead of G-flat, how long would it have to be?

That one is actually pretty straightforward if I'm understanding it correctly: it would be the length of an F attachment + the length of a Gb attachment. According to Andy's chat from before, it looks like it'll be about 5' of tubing!

That makes sense! Thanks!

Rrova wrote: ↑Fri Aug 17, 2018 6:38 am So if I wanted one of my valves in the key of D instead of G-flat, how long would it have to be?

REALLY long. See this: https://www.ebay.com/itm/Yamaha-Dual-Tr ... C7000%7C10

Apparently, this guy insisted on playing through one valve at a time! But he paid a steep price with all that tubing - must weight a ton!

Gatt wrote: ↑Wed Aug 08, 2018 11:49 pm Do you recall which model Holton tenor trombone has the 'G' attachment please?

I have a Holton TR650 with a G-att. I believe it is a .500-bore horn. The slide needs a little work; I haven't really used it. But it seems to play well.

https://photos.app.goo.gl/zqfJu9UQMz4CSCyTA

Sorry for resurrecting an old thread, but as the original TTF thread seems to be lost...

I have a King 607F which I had modified by Osmun Brass several years back to be F/G convertible. The trick is in the tuning slides being equal radius, which isn't the case for older 3BFs, for example, but seems to hold for newer horns. I'd actually like to make the same mod to a 605F and 3B+/F I own, both of which have equal-radius tuning slides.

The modification isn't cut-free: due to the lengths of the slides, the longer section of the attachment needs to be shortened:



(picture from eBay; edited by me)

A drawback is that you can run into clearance issues between the attachment slides and the tuning slide brace. I found that I needed a counterweight after the modification. And of course, you lose E pull, though you might be able to get that back with a custom tuning slide.

Due to a recent move, many of my horns, including this one, are in storage halfway across the country Once I've got it back, I can post a couple of pictures of how it all works. It was a relatively inexpensive mod: a few hundred dollars, IIRC.

John

I'd like to see it. Also, I did cut that 36BO and it plays like a champ. It's fully convertible to G or F since I have tuning slides for both.

Is a G attachment with F pull possible?

harrisonreed wrote: ↑Thu Feb 27, 2020 3:04 pm Is a G attachment with F pull possible?

Not with a straight pull, you'd have to add a section. or replace the slide.

I wonder about like a tube within a tube within a tube. Like a telescoping mechanism. Maybe that would just sound horrible.

Such a mechanism was created for the slide section of a trombone an acquaintance of mine in the army possessed. It wasn't a custom job for him but I can't remember the name of the maker.

harrisonreed wrote: ↑Thu Feb 27, 2020 3:04 pm Is a G attachment with F pull possible?

Figure the open horn is about 9' (108 inches/~274 cm) long. To lower the pitch 1/2 step, you need to add 5.95% to the length (and remember, it's like compound interested, so the first half step is 5.95%, the second is 5.95% of the open horn plus 5.95% of the length you added to get the first 1/2 step). To lower the pitch a step and a half, you'd need to add 18.9% (about 20.5"/52 cm). To lower the pitch two and a half steps, you'll need to add 33.5% (about 36.2"/91.2 cm) to the length. That means that somewhere in an attachment that is about 20.5"/52 cm, you need to find enough room to put a 15.7"/39.9 cm pull, leaving you about 4.8"/12.2 cm for the crook, bends, and the length added by the valve itself - plus you need to allow a little extra pull for tuning purposes. Gonna be pretty tight, I think it would be doable.

Maybe start with something with a flat wrap and tight bends out of the valve (like this Getzen) Tip the valve (like on a Benge) so you don't have to put any dogleg in the attachment to clear the main tuning slide and make the attachment a single long loop.