something that probably no one would ever dare try

[bloke]

putting an actual hole somewhere down the bugle of a tuba in order to lower a pitch or a group of pitches (for improved intonation)…

… but what if it actually worked, and didn’t make that tuba sound “leaky”?

[Snake Charmer]

Some high-end rotary trumpets are fitted with two "overblow keys" and a long lever for the waterkey, located on the main tuning slide after the very short leadpipe and valves. As you see them in many german top-level orchestras it seems to work.
According to some trumpet players they help to secure some delicate notes, which a piston trumpet doesn't have!
A hole at an intelligent place may will change the playing and tuning characteristics of a tuba. Most times I found leaks in some instruments the playing was afflicted, not the sound. And some leaks I only found while rinsing the horn. Unfortunately the leaks were all in bad places so the horns played better after closing up
In the late 19th century Courtois made ophicleides with an extra hole in the bell (without key), for egalizing the sound between keyed and "closed" notes (the same as "open" notes on a valved instrument)

[hubert]

https://www.martin-schmidt-potsdam.de/w ... lappen.pdf

Is this what you are indicating?
I have seen some of these once on a tuba restored by Matthias Vogt from Leipzig (Passion in Brass). Do not know, what the exact effect was.
Hubert

[matt g]

Wasn’t there a tuba posted somewhere that had a strategically mounted water key on the second valve slide for this purpose?

[BramJ]

My Besson 994 has 4 waterkeys (main, 1st, 3rd, 4th) I'll try what it does to the pitch

[YorkNumber3.0]

.

[Dan Tuba]

One of those JinBao 600F tubas would be a great candidate for such an "enhancement"

[WC8KCY]

My Boosey & Hawkes 8-10 B-flat soprano clarinet has a ~5 mm hole in the bell joint right up next to the tenon socket. It improves the tuning relationship between E/F below the staff and the in-staff B/C, with no loss of tonal focus.

Seems to me it would likely work on a tuba, but unless there was some set of calculations that could be used to determine where the hole should be located along with its shape and size, it would be a lengthy and very labor-intensive trial-and-error endeavor.

Perhaps an organ builder might have some insights on how this could be done.

[Mary Ann]

Reminds me of the guy who dropped his mouthpiece on his rotary F tuba and created a node that made the low C play like a piston tuba. There is as picture of it somewhere way back on the other forum.

[the elephant]

What’s that old “bullet hole in a tuba” saying?

It was in the hilarious booklet "Les" Brass" from back in the early 1980s.



It went something like, "A pinhole in a trumpet can render it unplayable, but a bullet hole in a tuba will go unnoticed."

[iiipopes]

Wouldn't it raise the pitch - in the manner of an ophicleide? As above, although I have never had the privilege of playing a rotary trumpet, it is my understanding that on these trumpets one or more water keys are placed so that when depressed, the open hole, just like on a woodwind instrument, functions as a register key to help intonate certain higher pitches. My take on it is as a kind of hybrid between a rotary valve instrument and an early 19th century keyed bugle.

[BramJ]

He posted that today... is he reading here?

[pjv]

Wouldn't it raise the pitch - in the manner of an ophicleide? As above, although I have never had the privilege of playing a rotary trumpet, it is my understanding that on these trumpets one or more water keys are placed so that when depressed, the open hole, just like on a woodwind instrument, functions as a register key to help intonate certain higher pitches. My take on it is as a kind of hybrid between a rotary valve instrument and an early 19th century keyed bugle.

As far as I know: yes.

Modern made barok trumpets (natural) sport three holes for tuning.

But aren't there computer programs nowadays for making tubas in tune?
I'm making a joke, but I'm also serious.

[bloke]

The bugle taper programs help make the worst problems not as bad, but still at the expense of former non-problems.

[Stryk]

How do you go about finding where each node is generated? I'm thinking about a frankentuba I have that everything is close to in tune except bottom line G, which is a half step flat. I have it disassembled and and starting to put it back together now. This would be a good time to experiment!

[cjk]

Reminds me of the guy who dropped his mouthpiece on his rotary F tuba and created a node that made the low C play like a piston tuba. There is as picture of it somewhere way back on the other forum.

IIRC, this guy's name was Steve Hoog and he lived somewhere around Chicago. The F tuba was a PT-10. The dent was on the body of the tuba close to the 5th valve.

[cjk]

How do you go about finding where each node is generated? I'm thinking about a frankentuba I have that everything is close to in tune except bottom line G, which is a half step flat. I have it disassembled and and starting to put it back together now. This would be a good time to experiment!

I had the dogleg after the main tuning slide and the main tuning slide replaced on a big piston CC tuba of mine. It was a MW 2165. A MW 6450 dogleg was modified to fit and a custom main tuning slide made. Both the 5th and 3rd partials moved. If I remember correctly, the fifth partial E went from flat-ish to in tune. The third partial G went from a bit saggy to a bit flatter.

[bloke]

How do you go about finding where each node is generated? I'm thinking about a frankentuba I have that everything is close to in tune except bottom line G, which is a half step flat. I have it disassembled and and starting to put it back together now. This would be a good time to experiment!

I had the dogleg after the main tuning slide and the main tuning slide replaced on a big piston CC tuba of mine. It was a MW 2165. A MW 6450 dogleg was modified to fit and a custom main tuning slide made. Both the 5th and 3rd partials moved. If I remember correctly, the fifth partial E went from flat-ish to in tune. The third partial G went from a bit saggy to a bit flatter.

in summary, then:
trial-and-error

bloke "sort of like calculating valve circuit lengths via 12th root of 2 calculations...and then discovering that they're all (not millimeters, but) INCHES off from useful lengths"

[Yorkboy]

How do you go about finding where each node is generated? I'm thinking about a frankentuba I have that everything is close to in tune except bottom line G, which is a half step flat. I have it disassembled and and starting to put it back together now. This would be a good time to experiment!

I had the dogleg after the main tuning slide and the main tuning slide replaced on a big piston CC tuba of mine. It was a MW 2165. A MW 6450 dogleg was modified to fit and a custom main tuning slide made. Both the 5th and 3rd partials moved. If I remember correctly, the fifth partial E went from flat-ish to in tune. The third partial G went from a bit saggy to a bit flatter.

This may sound a little nutty, but I’ve always suspected that what makes the .750 bore Grand Rapids York tubas play so well (among a few other things) is the one piece of @ .782 tubing found on the small side of the MTS, coming out of the 4th valve. It’s the only place on the horn where that size is used - the large side is @ .812.

3/4 - 25/32 - 13/16

[cjk]

How do you go about finding where each node is generated? I'm thinking about a frankentuba I have that everything is close to in tune except bottom line G, which is a half step flat. I have it disassembled and and starting to put it back together now. This would be a good time to experiment!

I had the dogleg after the main tuning slide and the main tuning slide replaced on a big piston CC tuba of mine. It was a MW 2165. A MW 6450 dogleg was modified to fit and a custom main tuning slide made. Both the 5th and 3rd partials moved. If I remember correctly, the fifth partial E went from flat-ish to in tune. The third partial G went from a bit saggy to a bit flatter.

in summary, then:
trial-and-error

bloke "sort of like calculating valve circuit lengths via 12th root of 2 calculations...and then discovering that they're all (not millimeters, but) INCHES off from useful lengths"

Yeah, my point was mostly that monkeying with these parts moved around the 3rd and 5th partials, so the 3rd partial which Stryk might want to mess with is "in that ballpark" of the tuba and that if you fix one partial, you might un-fix something else.