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Eventually I want to have my 20J converted to a 4 front valve, short action horn..Since these are so rare like 36J's and 22J's, I want to make my own. How could you go about doing this while keeping the .770 bore? I thought about getting a 20K valve section and adding a 4th valve and slapping it on my tuba. But I don't want the smaller .734 bore. Or could I use my valves from the 20j and get a 4th valve from a 25J and switch some tubes around to make it front action? Here is a pic of what i would like it to look like. But mine would be satin silver with an upright bell of course..and what is the model number for this horn? Tubaexchange called it a 24J but that is a top valve version

If you want to minimize your risks of total failure, tuba-acquisitionwise, buy a 5 valve piston Fafner.

You are operating with so many unknown factors on the basis of a frame, which not everybody consider worthy of your planned efforts.

Klaus

It's GOT to be possible..

.

I just bought a recording bell Conn 20J from Bloke with the same setup as that of the OP (3 valve top loaded). I prefer the way this horn plays and sounds to that of the brand new Miraphone 5v 1291 BBb I recently sold at Dillons after I got my 5/4 Rudy Meinl BBb. The 1291 is a great horn, but the 6/4 horns (the "5/4" Rudy is 6/4) have a sonority and presence that can't be duplicated (by me) with the smaller horns.

Gravitas ...

I have 3 or 4 Conn short actions valves that came from the 20J's. If you are needing one to create a 4th. I believe that I have a 1st, 2nd, and two 3rd valves. But I'd have to go out in the garage and check. They all have had the knuckles removed. I do have a few extra knuckles too.

I also prefer the sound of this horn above any new horn like the previous post said. I'm not interested in buying a NEW horn right now. I know this is possible because Harv cut one down to CC a while back and made it a front action tuba. I think this would be an amazing horn to have converted.

I'm doing this right now... .
Although I'm not keeping the larger bored pistons, I am going the "simple-er" route and using a sousaphone valve set. Plus when I want to (or have money to) add a fourth valve parts will be easy to come by. I'm not quite as worried about the bore size, just how in-tune it plays once I'm done cutting and "pasting" it back together.
I played mine in a sort of "last hurrah" today, in concert, it was fun but it'll be nice once it's done.

Please post pics when its done! You got me interested in wanting to do this. I plan on getting valves from a 24J... and attaching it to possibly a 20K valveset using the right elbows and attaching the 4th valve tubes somehow..I dont know this will work out but its definately a possibility

I stripped the old scratched lacquer this past weekend and brasso-ed the bell, it turned out quite nice. If you plan on doing this I'd recommend Aircraft brand peeler. Works great! But wow, a 20J is a LOT of surface area to polish. Currently I'm awaiting my repair-man's vacation to start (Day job) so I can get going on the main job at hand.

I hope you are planning to do all the work yourself and are prepared to perhaap have a pile of brass that is worse than what you started with. I shiver when I think about how much this would cost to have done.

I know you are a young guy so I wonder how many BBb tubas you have actually played. I gotta think that there must be something suitable out of the box in the way of a 6/4 BBb horn. Holton 345? Fafner? There is a 6/4 Willson on Oberloh's site that looks big and meaty!

If you wanna do this, have at it but really think it over first. Planning it out in your head or sketching it on a napkin over dinner with your pals is really different than actually accomplishing the task.

I don't plan on mixing bore sizes. I plan to get a 4th valve from a beater 24J and stick it on! I know this is going to be extremely difficult but I think it will be worth it if it turns out good. Again, I'm not looking to buy a different tuba such as a Fafner or others mentioned. There is nothing like an old Conn. But hey, if it turns out a total failure..then I'll try again! Have faith people

TUbajohn20J wrote:I don't plan on mixing bore sizes. I plan to get a 4th valve from a beater 24J and stick it on! I know this is going to be extremely difficult ......

Don't scrap a 4V valve section to get a 4th valve. Scrap a 3V one and salvage the 2nd piston and casing.... leaving as much of the cross-port tubing as possible. I've done this and it's certainly not easy. I just finished building a 4V oval-port valve section for a Conn short-action euphonium project. It wasn't easy!

Like others have said.... don't simply charge into this project. I've built several 4V valve sections for both Kings and Conns using donor parts and that 2nd valve has always been the one that works best. You'll see by taking a look at the open bugle on just about any valve section that about the only way you'll match the 'in and out' ports is to use a 2nd valve.... unless you want to stagger the height of the 4th valve.... maybe not a bad thing to think about but a little uncommon.

Bear in mind that since the pistons for the short-action sousas are not the same.... and that the 'J' series is no longer being produced... you may seriously consider using 'K' series parts even though the bore is slightly smaller. Bigger is necessarily better! The idea of using top-action components to build a front-action horn is wrong from the beginning.

This is a going to be a tough project. Even with the experience I have building 'Frankenhorns'... I would not take on this project for a customer and promise any good results.

I'm a new owner of a 20J and absolutely love it--currently using it in one of my ensembles and gotten quite a few compliments about it. I'm not a fan of altering original tuba designs (especially the mutilation of fine old BBb horns to turn them into CC horns--IMO a crime against nature! [mini rant over]) If you insist on doing this, I hope that:

This is not your main axe.

That you realize once you start cutting on this instrument it will NEVER sound the same again.

There is no starting over--only going forward with whatever you end up with--which could be a pile of 1st rate brass scrap.

I hope you really give this some more thought--Best of luck.


JJ

Brian, your homemade plastic tubas prove, that you are specially gifted in making ideas end up in real stuff. So I understand you encouraging experiments. But then I seem to remember that even you have gone through frustrating phases, where you ran into problems delaying your projects.

I am conservative on taking playable instruments apart to let them be transformed into something with a bleak prognosis. Changing a top valve block into a front block is tough in the first place. Adding another valve or two adds to the problems.

If somebody has large ressources in form of money, tools, parts, back-up instruments, skills, and mental surplus there of course will be no need for reservations.

Klaus

Hey everybody thanks for the advice. Also, I do agree with Tubad somewhat because I too am against cutting good BBb tubas down to CC. My 20J is going to stay BBb no matter what I decide to do to it. It's obvious The "easier" way to do this would be to get a 20K/22K valve section instead of the .770 valve section. But I want this horn to be as close to a 22J or the 4 valve version as possible. This is probably a dumb question but is it possible to keep the 20J valves and casings plus a 2nd valve from another 20j for the 4th valve, and attach it to a 20K valve section? would the knuckles fit even though they are made for a .734 bore? Also I would like to have the "lowered" 4th valve position like the factory horns, but if that would cause too many problems I would keep them level. If I did this and it turned out great, I see no need to get that new silver Willson 3100 FA5 like I was planning on eventually getting. I am going to see how tubatom's 21J turns out and look at the pictures before I start anything. Or better yet, where can I find one like this from the factory so I can buy it, and keep this on like it is? haha, yeah right!

Now that you mention it, a seven valve 20J might be worth making. HA, just kiddin'. But ok, thanks for the advice. I'm still thinking "there's GOT to be a way to convert my 20J valves to front-action without going to the smaller bore size".

Here's my plan:
1) take it apart and de-dent it (it's a post-public school horn with flat edges on the stack after all!)
2) put it back together with the bows flipped so that the bell stack is on the "right" side (to the player)
3)take my 20K valve section and graft it in, utilizing the main slide from the 21J (the small side fits the 20K valve section)
>>>>to do this I am leaving the pipe that houses the large side of the main tuning slide (20J) and removing the matching/similar part from the 20K set. Since my 20K valve section is missing a length of tube after the main slide this situation is ideal and can be easily done, and i wont have to mix match the size of tubing after the main slide. Pictures posted below.

in the above pic it shows the damaged section on the 20K set that I intend to replace with the 20J pipe (dark green)

in this picture it shows the mentioned that is to be saved. (Green)

I played it for the last time pre-alteration yesterday and here is what it looks like as of now.

You could just settle for one of these:

Couple things...

First, you could use the original valve section... I've thought of this many times. You would lay the section in perpendicular to the body in the front action position - Perhaps akin to a York angle. You'd need a new leadpipe. Leave the second valve slide alone. Cut the top bows of the 3rd and 1st valve tube assemplies in half, and solder them to the knuckles. Attach the tuning slide tubing to there (perhaps with a couple extra knuckles) and remove a little for the extra bends but more for the fact you'll require a wider u bend (insert a straight piece in the bow perhaps?) If this makes no sense, I'll draw a picture.

Second... I'm hoping to pick up a 20J to convert to front action with the sousa valve body. These horns are always sharp (I've found) and a little longer leadpipe and 3rd valve branch to the tuning slide might be a good thing, worthy of the experiment.

Unlike cutting 6/4 Holton and York BBbs, there are a billion of these things around, so I don't feel it's a desecration to play with one. At this point, they almost deserve a little experimentation - cull the herd!

J.c.S.