Making a 90G trombonium convertible

[Thrawn22]

Hi all,


As much as i don't like cutting up unique or classic horns, the design of the 90G makes it very tempting.

For those who don't know what a 90G is, it's an upright valve trombone Conn made for marching band. What makes it intriguingly genius (or dumb depending on what side of the fence you're on) is it's an 8H bell section (reciever and all) mated with a valve section. Now the only thing keeping it firmly on other than the bell receiver is a few braces.

My idea is to make the bell section detachable so i can utilize the bell section by itself. "Why" you ask? The 90G is nickel plated, and I've wanted a nickel bell large bore since i tried an 88HN years ago (almost as rare a horn as the 90G). Also i would like to see if a largers bell would give the horn a more baritonish sound.

Thoughts?

[hyperbolica]

I'll tell you what. You sell me the 90g and then you can do whatever you want with the money. I'll just play the 90g as it is. I should have bid on that thing, especially for the price you got it for.

[glenp]

I don’t have anything to say about the 90G idea; but if you’re wanting an 88HN I’ve got one that I’ll be posting for sale soon. Let me know if interested.

[Matt K]

It’s hard to improve on an Elkhart 88 bell, imo.

[brassmedic]

That's a lot of braces. You'll have a bell with a bunch of connectors sticking out of it, I guess. Not sure what mechanism you'd use to make the short braces detachable. And how would you make that long flat brace that supports the leadpipe detachable? And then would you put the same kind of connectors all over the larger bell that you're planning to use with the valve body? And make them shorter to account for the larger diameter of the bell? Or were you just planning to take all the braces off entirely and have a structurally unstable instrument?

[brassmedic]

Another question is, can the receiver on those be uncoupled or is it soldered together? If the tenon and nut have a bunch of solder inside, it's not gonna be fun to clean up so that it functions correctly.

[elmsandr]

One of my "stupid projects" that I've wanted to do was make a new version of this but utilize a bass trombone bell section instead of an 8H.

As Brad notes, you are going to have a heck of a time making the leadpipe stable in the existing configuration, but you could probably do something more like a Sousa neck... but you'll have to move stuff around. May want to start with the assumption that you'll need a different leadpipe angle and a different way to hold the horn if you want the bell section to come off.

Hadn't figured it out yet, but that 24I that is sitting in the classifieds would make an interesting valve section to base this on... but I think I want ~.580-.590 or so.

Cheers,
Andy

[Thrawn22]

Another question is, can the receiver on those be uncoupled or is it soldered together? If the tenon and nut have a bunch of solder inside, it's not gonna be fun to clean up so that it functions correctly.

I was wondering the same thing. That'd be the monkey in the wrench if they soldered the receiver. Until it's in my hot little hands i won't know what I'm dealing with. In the meantime i can't wait to get it.

One of my "stupid projects" that I've wanted to do was make a new version of this but utilize a bass trombone bell section instead of an 8H.

As Brad notes, you are going to have a heck of a time making the leadpipe stable in the existing configuration, but you could probably do something more like a Sousa neck... but you'll have to move stuff around. May want to start with the assumption that you'll need a different leadpipe angle and a different way to hold the horn if you want the bell section to come off.

Hadn't figured it out yet, but that 24I that is sitting in the classifieds would make an interesting valve section to base this on... but I think I want ~.580-.590 or so.

Cheers,
Andy

That 24I is tempting just for the fact it's in a bit better shape than mine and i wouldn't mind a forward bell to go with my upright. And parts. Parts are nice.

[hyperbolica]

One of my "stupid projects" that I've wanted to do was make a new version of this but utilize a bass trombone bell section instead of an 8H.

As Brad notes, you are going to have a heck of a time making the leadpipe stable in the existing configuration, but you could probably do something more like a Sousa neck... but you'll have to move stuff around. May want to start with the assumption that you'll need a different leadpipe angle and a different way to hold the horn if you want the bell section to come off.

Hadn't figured it out yet, but that 24I that is sitting in the classifieds would make an interesting valve section to base this on... but I think I want ~.580-.590 or so.

Cheers,
Andy

A bass trombonium is kind of a goal of mine too. The 24i in the classifieds is mine, but I don't think it's a great starting point. The bore is too small, and the stock receiver is for small bore. You might be better off with a larger bore euph. Maybe one of those cheap Chinese models, and then get a smallish baritone bell. Better yet, a 5 valve F or Eb valve cluster from a tuba hooked up to a smaller throat bell. There is someone on the tuba forum who is building something like this, but it's in limbo for the time being.

[Finetales]

J.c. Sherman has built a few bass tromboniums in low Eb (picture here) for customers. According to this old TubeNet thread, he used a 10" G marching baritone bugle bell and a King baritone valve set.

I'm sure one in Bb with a bass trombone bell (just find a cheap Miraphone or Yamaha single valve or something) and 5 valves would be lots of fun.

[Thrawn22]

So i got it today. It's quite phenomenal. The big hang ups are that it looks like Brad is correct that Conn soldered the bell receiver to the valve section. And if i move braces around to more user friendly spots I'll have bare spots of brass since they nickel plated in post.

In anycase it plays great as is. Very open blow and good trombone sound despite the valve section.

[greenbean]

I would keep the 90G as it is and play the $hIt out of it. But also buy that 88HN mentioned above!

Anyway, that is my 2 cents...