WTH? A Holton 345 6th Valve?

[the elephant]

I did some mocking up; I did some photographing. I even did some measuring.

I checked my parts boxes. I looked through my junk drawers.

I espied my horizons.

I'm going to do it, dammit.

I remembered that the 5th valve section of the 345 is fully removable SEPARATE from the piston section. Further, I realized that zero tools are needed to remove the 5th valve section and swap in a straight piece of tubing, making this a four-banger that wears a little less on my lower back and hips when I lug it around.

However, since the weight difference is not nearly as much as I had hoped I never avail myself of this "feature". (It is nice to know that one day when I have to take apart the rotor to clean it out, replace the corks, etc. I can do it VERY EASILY.

Things I have recently noted about this setup: I have the exact, same Miraphone .837" rotor sitting on my bench, brand new and sort of homeless. I ended up not needing it. The only difference is that the one on the Holton is brass with nickel silver knuckles, and the new one is all nickel silver. The only problem I have with this is my inborn OCD nature.

Further, there is room for another rotor between the 5th valve and the sixth branch of the bugle. Right now it is set up as a mini slide. The valve is attached to the bugle via a very short, snug (and greased) inner/outer slide leg. I have to come up with a suitable connection point between that branch and a rotary valve knuckle. If I can do that I have everything needed here to make a slide, a lever, and a linkage.

Joe added that 6th valve to his old 2165. It was simply a tuning loop and not a usable valve by itself, however, when not in use it was still an extra twist to the open horn. AND IT DID NOT AFFECT HOW IT PLAYED AT ALL. Since that 2165 and my Holton blow so similarly I am feeling safe to believe that another rotor in the open horn would not change anything at all in how it plays.

Boys and girls, I love the six-valve system of my Kurath so much that I am dying to try it out on a CC just to see what it allows me to do, technically. Right now, without moving any slides, the horn plays quite well in tune with a few alternates. Mostly I use 13 on that overtone series (rather than 4) and for low D I pull 1st. (Oddly, bottom line G is only a tad flat and I play it 0.) However, all notes I would use a half step down have to be played 24 as my 1st slide is too short to pull out far enough for 123 to work. And below the staff in certain keys where you have to move around a lot between 13 and 24, I have a hard time at this age. But 136 would be pretty easy. If I ever had to trill Db to D (okay: never gonna happen) 136 to 13 would be a cinch.

So why not? I can make a separate 5th/6th section from one that is just 5th, and swap them out with the straight tube so that this horn could be converted to 4, 5, or 6 valves in ten minutes using zero tools.

Use for this? Probably very little, but HOW FREAKING COOL!

So I was a good dog and did my math, took my pics, made my mockups… and it works!

So I am going to add a 6th valve (that is fully removable) to this tuba because I want to. HAHAHA!!!

It will go here. There is room for a Nerf football between the back piston caps and the 5th slide. Seriously, you could stick a brown bag lunch in there, so a shorty 6th slide will be no problem.


So the 5th unit's inner slide leg is in the way to see how this will fit, but I slapped a bit of the outer tube on the valve as a ferrule and slid it over the connection with the sixth branch of the bugle and you can clearly see that, despite being tight, there is more than enough room for the knuckles without hitting the 2nd piston bottom cap. To clear this the vale has to be installed at roughly a 45º angle whereas the 5th is flat. This does not add to the issues surrounding the linkage and where I want my lever to be, which is suboptimal, at best. But everything *will* work. The blue circles show where the ports will be when the valve is in its correct location.


Oh, no! You can't get to the back cap, so the rotor cannot be removed! REMEMBER: Not only does the whole valve section come off of this tuba, but the rotary valve section can be removed separately from the pistons using no tools.


Another angle from that perspective…


Move that over to the left about an inch and a half and you got it. The 5th will be almost exactly where it goes right now. I can install all this and only have to move the base of one brace to get it all to plug in correctly.

[the elephant]

The lever would be a hinged bar across the back of the 1st slide that I can access from any position so long as I have my hand on the slide crook. It would be pulled from back to front by my left thumb.

[the elephant]

Anyway, I think this will be fun to do, won't cost me anything out of pocket, will be pretty easy, and will add some functionality. Will that be USEFUL functionality? Who knows? I never thought I would like a 6-valved F tuba, and I was seriously wrong about that.

Also, another experiment is to make an extended slide to drop 5th to the flat major third (or 23) used on Mirafones in the old days, which I learned and sort of prefer.

That would make this tuba have 4 pistons PLUS:

• M2 5th
• M3 5th
• M2 5th, m2 6th
• no 5th or 6th

Move over, Jinbao. I'm going to get "more bang for my buck" without you.

[Tubajug]

I eagerly await another excellent build thread!

[the elephant]

I *thought* I had everything I needed to do this.

I was sadly mistaken. However, I can get by with what I have. I need a 2nd crook for the bore size I am using, and I don't have one. I do, however, have a 1st crook, so I made do with that. Of course, this leaves me with a nearly functionless slide, with a mere one inch of pull, so I had better get this right because there will be next to zero adjustability. <sigh> I am making this so that it will be easy to pull the slide from the valve and make another using the needed crook once I get one. I may play this and decide it is not worth the expense and time. I really don't know yet.

Anyway, I managed to hack together two runners that will allow for the use of a 1st crook. I cut the four needed ferrules and then had to screw around with the two runners, nipping out length bit by bit to try and regain some for the slide legs. It took me forever. Two ferrules and the runners have been soft-soldered to the case of 6, using the crook as my alignment point. This will help me line up the very short legs, which I will cut and install tomorrow… maybe…

Si once again, this is not going to plan, but it will work just fine. In the pics, the crook and its two ferrules are just press-fit. The 5th is still in line with the 6th, so I need to take them apart from one another so that I can fiddle with the angle of the 6th.

I still have to decide how I want to attach this to the bugle. I think what I already have would be good, but the parts have to lose about half of an inch of length to work. Hmm…

[bloke]

I feel you on this mod. If I still owned a C instrument and was still fighting low D tuning, I would be scratching my head about a way to get this done... and sure, it dials in other things as well. With the instrument I have, that pitch is obviously now C, is rarely requested in gig sheet music, and the third-valve-alone fake version is remarkably good - which is something to which I wasn't accustomed (but which obviously pleases me).

In regards to that circuit loop, am I still considered to be a manly man if I refer to its shape as "cute"?

Once done, where will you then be storing your lunch?

[the elephant]

Alas, I must now eat in the car on the way to work.

I finished the 6th circuit. It has a nice pull sans "ting" upon extraction, so despite being difficult to align due to its shortness — I nailed it. Horray, me. I would like to add one of those 186 one-piece braces, but being of a fatter bore, I am not sure if the radius of the crook is the same. I can always fit and install a three-piece brace, I guess.

The 5th and 6th are still on the same plane, and they need to be more than 45º off, so I have to pull them apart, clean inside/outside the joint parts so that I can press-fit them together, and rotate them to the correct angle. There is a small chance that this slide will not fit the space, but I think all my eyes are dotted and tees crossed in that regard. Maybe not.

I have one major issue that I have to ponder as I sleep. (The best time for me to solve problems is when I am not actively worrying about them,) I still do not have a plan for connecting 6th valve to the sixth branch. I have ideas, and all will work, but not as well as what I have. So I need to be getting more sleep at night so I can figure this out.

If I can get this installed to the removable rotary section (well, since that is just the valve and the slide and the two ends that splice them together, I guess it is more like removing the old slide and installing it to this pair of valves) I can make my lever, which is something I enjoy quite a bit.

Connecting that lever to the stop arm on the 6th will be less amusing, but I think I have that sorted already. (I took a nap, you see…)

Porn time…





I hope everyone is having a wonderful day of thanks.

[the elephant]

Today I continued work on the Holton's 6th valve, and did some work on the Kurath using my lathe, which is the first time I have used it for real work since I bought and rebuilt it.

At great pains I separated the new 5th and 6th valves, joined by Miraphone using what appears to be solder made of 50% tin and 50% anger, based on the difficulty I had taking them apart.

I did facing cuts to the ends of two brass rods, center-drilled each end to a depth of about 10 mm, then tapped them to 4-40. I screwed in some all-thread and trimmed it to length. BOOM. New Kurath linkage rods for 5 and 6. Boring for most of you. Lots of fun for me.

I tore down the Holton and scrubbed that nasty thing out. I had never cleaned it out after having done quite a bit of assemblly work and buffing. It had a big clump of… something… impregnated with tripoli polishing compound in the leadpipe. (It played great, too. Go figure.) I soaked it in vinegar and then hot, soapy water, and as I said before, a lot of gunk came out. Comme c'est charmant.

I finally finished adding the decorative tubing end rings that help stiffen the edges of the outer slide tubes. I decided years ago that they were very attractive but not really worth all the extra work. The issue with finishing the job was that I did not have the next tube size up in the system that Miraphone uses. So I had rings on all the slides save for the large side of the the MTS and either side of the 5th, but with 6th now in need of these, too, and my having an ample supply of the needed tube, I cut five new ones and installed them. At least everything matches now, because it *still* isn't work all the fuss.

Separating the two new rotors allowed me to do more mockup work, which was what I needed, since I was bugging out over a possible miscalculation that might have made my slide unusable. However, the slide has no clearance issues behind the pistons. Nice.

In other news, I am well and truly back to work as in the old days: I burned TF out of my hand. Yep. Good, old Wade is back in the saddle again. I hope my insurance is current…

The COVID is losing its hold over me and I got a lot of work done. I am glad this crap is going away and hope I never catch it again.

Here is a fit test of the 6th slide, but 5th is still attached, and should be nearly 45º over from this orientation. (I get to that later…)


It looks tight, but it isn't. But even if it had been IT'S OKAY BECAUSE IT IS ALL REMOVABLE. Maintenance can be done "off the horn".


Here are the two rotors in their intended orientation. Hey, check out those sexy tube end rings on that slide!


My little Commie DDR laboratory lathe finally got used for actual work today. I did very little, yet I had a ball doing it. I have improved my ability to produce accurate work by a huge amount. I m so stoked to have this very accurate, little device!


Look at that! Dead center, dead straight! I used to work so hard on stuff like this, only to get mediocre results. Now it is easy. I am a fortunate guy.

[the elephant]

Diese Scheiße klappt bei mir nicht.

I'm working on it, but just about any way you slice it I will have to lose .75" of MTS pull, and that ain't good, friends. I need to think about how short my connection to the bugle can be without becoming *fragile*.

I'm out of here for a few days. I feel the need to chew cud and cogitate.

[bloke]

Most all of us understand the the difficulty of a contrabass tuba tuning slide being the same length or even shorter than those found on trumpets, horns, and trombones, yet our instruments are four times or at least twice as long.

It's a rare instrument that I acquire which does not require me resetting the tuning range of the main slide so as I've got just enough push for 64° in the winter and just enough pull for 78° in the summer. That uses up just about all of what I have typically, and it needs to be pretty much precision-centered to be able to accommodate those extremes.

I'm not posting anything that Wade doesn't know, but I might be posting something that some of those of you - with generous length main slides - don't have to consider.

Also, I continue to insist that my ears are not the world's best, yet I seem to find myself pretty triggered when I'm not able to play up to pitch or down to pitch at home, so I must be able to "hear" fairly well.

[MiBrassFS]

Sweet commie lathe! And, nice work!

[bloke]

I have absolutely no idea...(??)...but - if your 2-3 G-sharp (bottom space of the staff) is typically saggy, a 6th valve could possibly come to the rescue with some sort of combination...

If that pitch - with this instrument - doesn't need any help, consider yourself blessed.