Shortening a valve slide

[Mary Ann]

How big a deal is this? (not asking whether it's a good idea -- it's MY tuba.)

[arpthark]

The slide itself, or the entire valve circuit?

[bloke]

If possible, I always try to shorten the stuff that leads up to the slide tubes, rather than shortening the slide tubes themselves.

You have some Miraphone tubas. I have one as well. I shortened the #1 circuit as well as the main slide. I took away no slide tubing from either one of those.
I also added range to the #3 circuit along with lengthening it's shortest possible length, as well as adding pulling range to the #4 circuit. (I had no reason for doing the fourth circuit thing, but I thought "What the heck, someday I may find a reason or purpose for extending it way out", and I was replacing a couple of slightly damaged outside slide tubes on that circuit anyway.)

Your question was whether it's a big deal. It was a big deal to do all of those to my own satisfaction. Each one required a considerable amount of time and concentration.

With silver plated instruments - if there's an attempt to mar up that finish as little as possible, that's another big deal. My instrument is lacquered, and there are places where the lacquer is a little bit burned and there are also places where I replaced tubes that I've not yet bothered to shine up and spray clear over them. I'm not going to lie and say "I don't care about the looks, and only care about the sound", but I do find that I need to get on with things and get back to making money - rather than continuing to work for myself for free. Sometime, I'll polish all the areas that are not shiny - which I altered - and spray over them. I did go ahead and do the main slide, because it's so noticeable.

[Mary Ann]

The slide itself, or the entire valve circuit?

I can't answer that because I don't know enough. I am in the apparently unchangeable habit of using 3 instead of 12 unless there is a specific ergonomic reason in a fast passage to use 12. On one of my tubas that is otherwise easy to play in tune, 3 by itself is flat. I found a discussion of this tuba on the old forum, and this was actually discussed, that A is flat on this C tuba. It's in tune enough with 12 but not with 3, and I find I'm too old and have way too many years on a C tuba of using 3 for A, so I want to shorten what I have to, to get it up to pitch. Those who came up through a band program have 12 ingrained, but I came from the French horn world where use of 3 is very common.

[bloke]

It's not uncommon for three alone (and pushed in all the way) to be a little bit longer than 1-2 in their normally tuned positions.
If you use third valve for everything that most people play with 1-2, I understand wanting to shorten it.
Since all of the pitches in most any overtone series vary in tuning, the reason most people play them with 1-2 is so they can move their first slide on the fly and micro adjust the tuning... unlike horn, we can't easily stick our hands in the bells of tubas and tweak the tuning that way.

[Mary Ann]

On my horn, all valve slides and the tuning slide are within milimeters of being all the way in, I don't find it necessary to waggle my hand in the bell, and to my ears I can play it in tune because it is a flexible instrument. If it is really hot outside yup the tuning slide will come out some. I have played horns that were otherwise fine whose slots were so narrow that hand wagging was a necessity. Some prefer that to help them hit the notes.