Main slide trigger suggestions.... please

[Mike-ICR]

Hi folks,

A while back I acquired a large Buescher Eb tuba. I added the 4th valve, shortened the main slide (to standard pitch), and did some basic body work. It plays in tune throughout aside from a little sharp on the open notes above Bb in the staff. I can 'lip' those few down (and have been) but tone quality suffers. The obvious (to me) solution is to install a main slide trigger.

I'd like suggestions, pictures, drawings or whatever to help me figure out how to add such a thing. I've added slide triggers before on several instruments but never a main slide trigger and never on a 'sousa style' piston set like this. I'm a little stumped. I'm thinking it would be good as a right hand thumb trigger to keep my left hand free for 4th slide pulls and page turns and so on. One thing I KNOW FOR SURE is that I don't want a long T-bar handle type rod.

Any help is greatly appreciated.

[imperialbari]

It may be splitting hairs, but I do not agree in the description of the pitch of your instrument. It isn’t the 4th partial and up that are sharp. It is the 2nd and 3rd partials that are flat.

If you mount a trumpet style adjustable slide stop, you may hone the main slide to easier movement without making it leaky. The slide stop will prevent it from dropping off. There are more ways to mount springs to keep the slide extended to the position set by the slide stop.

Use the 4th partial as the tuning note to set the slide stop. Mount some sort of thong on the main slide stay, which will allow your right thumb pulling the slide upwards when needed in the lower range.

Klaus

[tokuno]

Assembly instructions:
1) Use only "off" (non-tapping) foot

Tips:
1) Avoid strolling gigs. If unavoidable, Hop on free foot.
2) Beware snagging late-arriving trombonists.
3) Should the connecting string snap, use direct-drive. Preparatory yoga recommended.

Restrictions:
Not recommended for two-foot tappers.

Caution:
Select spring tension carefully. Use of garage door return spring can cause undesirable gross thigh muscle development.

[imperialbari]

Assembly instructions:
1) Use only "off" (non-tapping) foot

Tips:
1) Avoid strolling gigs. If unavoidable, Hop on free foot.
2) Beware snagging late-arriving trombonists.
3) Should the connecting string snap, use direct-drive. Preparatory yoga recommended.

Restrictions:
Not recommended for two-foot tappers.

Caution:
Select spring tension carefully. Use of garage door return spring can cause undesirable gross thigh muscle development.

I look forward for this suggestion in action being taped on video and put on Youtube.

Klaus

[tokuno]

Can't see how much space there is behind the 1st valve slide, but how about something like this?
Thumb lever poking through 1st valve slide (roughly parallel to valves), with the connecting lever at 90 degrees to the thumb lever.
Might be insufficient throw to lessen the effort. I.e. might require too much leverage.
And to gain the leverage means losing accuracy, so fine tuning would be really hard.
Also might be too much play between the two levers.
But might work with very light friction on the tuning slide and a push/pull ring instead of spring return (to reduce load)?

[Mike-ICR]

I thought the same at first, Klaus. When I first noticed the problem I was already warmed up. I checked it against a good tuner and found that everything was playing a little sharp (about 5 cents) and the Bb, Eb and G in the staff were almost 20 cents sharp. I tuned the sharp Bb and found everything else flat (the Eb and G above that were in tune). I think part of the problem is that this horn was cut up to pitch from low pitch and I didn't cut the valve circuits.

I like your idea of adding a trumpet style slide stop. I will definitely to that! Great idea.

I love your diagram, tokuno (both of them). I think I'd like something sprung but I think you're on to something here. I'll try to mock something up tomorrow.