Question about the slide to bell connection.

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Bhrzg
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Joined: Jul 05, 2025

by Bhrzg »

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Hi all,

My first post here, and I know very little about trombones at this point, so bear with me...

I bought recently this trombone. It's an old Albert Wolfram "Sinfonia" from East Germany. I don't expect it to be any great instrument, but after cleaning and lubricating it, it seems to work nicely, I'm getting pleasing sounds out of it and am having a good time practicing with it.

But there seems to be something strange in the slide to bell connection. Please see the images below. At the end of the slide there's an additional piece of tube marked with a red arrow. This tube goes inside the tube marked with blue, which in turn goes inside the tube marked with green. So it's a kind of threefold joint.

However, when connected there's a small gap between the blue and green tubes, which means that the whole slide is able to wiggle a little.

This makes me think that the piece of tube marked with red is not an original part, but a later addition. It would make much more sense that the connection would be simply between the blue and green tubes, locked in place by their slightly conical surfaces.

What do you think, am I right with this assumption? But then, if I am right, then the next question is why this extra piece of tube has been added? And what could be done to it?

Thanks in advance!

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JohnL
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by JohnL »

That looks a lot like the tenon end of the upper inner slide.
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Bhrzg
Posts: 4
Joined: Jul 05, 2025

by Bhrzg »

[quote="JohnL"]That looks a lot like the tenon end of the upper inner slide.[/quote]
Thanks for your response!

Yes, it does look like that, but... the inner slides are the same length at the other end. If this is the tenon end of the upper inner slide, then the other inner slide must have been shortened. But what would be the purpose of this kind of modification, and why would it have been done so that one of the inner slides protrudes like this and becomes a part of the slide to bell joint?

Also, the diameter of the protruding piece of tube is a bit smaller than the inner slide tube (about 13,3 mm vs 14,0 mm).
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JohnL
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by JohnL »

What do you see when you look down the tube?

(you might need to do a little cleaning before you can see anything but aged slide muck)

(Whoops - we're actually talking about the <I>lower</I> slide; sorry about that)

Two reasons I can think of for that sort of setup:

1) Mechanical reinforcement, or

2) Eliminating steps in the bore through the tenon area.
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CalgaryTbone
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by CalgaryTbone »

[quote="JohnL"]That looks a lot like the tenon end of the upper inner slide.[/quote]

I briefly owned a Holten 185 that came to me looking like that. I had a tech work on it and he (a Bass trombone player) said exactly that. Luckily, he had seen it before. In the case of the Holten, the soldering had come loose in the receiver and then it came to be stuck in the slide. It was a bit of work for him to get it out and return it to the bell section.

The good news was that it was an eBay purchase that had obviously been a school instrument. Since the bell would flop over with this piece in the wrong spot, the horn had obviously been left in the case for years, and hadn't been completely trashed. A good tech can fix tha for you - be sure it's a horn that you care enough to put a few dollars into.

Jim Scott
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Bhrzg
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by Bhrzg » (edited 2025-07-07 9:50 a.m.)

[quote="JohnL"]What do you see when you look down the tube?[/quote]

Good question! I took a photo at the end of this mystery tube (please see below). I think it quite clearly shows a seam in there, which means this piece of tube is indeed an additional part, not just the end of the inner slide tube.

But is it a later addition put there for some reason, or is it an original part that is just in wrong place as Jim Scott wrote, i.e. should be soldered in the receiver but has come loose and stuck in the slide?

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Bhrzg
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by Bhrzg » (edited 2025-07-07 10:45 a.m.)

[quote="CalgaryTbone"]In the case of the Holten, the soldering had come loose in the receiver and then it came to be stuck in the slide.[/quote]

Thanks for the reply! This same diagnosis was suggested also by a user in Reddit, where I also asked about this. And I think it could really make sense.

But on the other hand, another Reddit user thought that this joint with the additional piece of tube looks too convoluted, because German trombones, according to him/her, usually had a very simple friction fit joint. So I don't know really...
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Blabberbucket
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by Blabberbucket »

If it fits together reasonably well, seems secure while playing the instrument, and the instrument plays acceptably in tune I would just leave it alone.