TubeNet

I would be very surprised if, at the point where the bell attaches to the rest of the horn, there was any dimensional difference between a 52J, a 54J (19" bell), and a 56J -- wouldn't make sense from a production POV to have three different diameters at that point when the only noticeable difference between the three models is the final bell diameter. I could, of course, be wrong ...

Elessar wrote:Greetings -

To the point: can one put a bell from a Conn 52J on the body of a Conn 56J?

Other than the 18 inch vs. 20 inch diameters, are they the same? Can a competent brass tech simply switch them out?
<cut>
I have a chance to get a stock (raw brass) 52J bell at a rather reasonable price, so I would appreciate any input you may have.

It would be easy to measure if you have ready access to both bells. Measure the circumference of each and if they are equal, it should/might fit.

What part of the world are you in? Geographically. it would make sense to pick someone close and you might not even have to ship it. Maybe drive a way but could avoid the shipping.

Kevin Hendrick wrote:I would be very surprised if, at the point where the bell attaches to the rest of the horn, there was any dimensional difference between a 52J, a 54J (19" bell), and a 56J -- wouldn't make sense from a production POV to have three different diameters at that point when the only noticeable difference between the three models is the final bell diameter. I could, of course, be wrong ...

I agree. I would be absolutely dumbfounded if the 52J bell didn't fit perfectly. If I were the original poster, I'd call Matt Walters at Dillon Music. I bet he would know for sure.

My understanding from when these were first introduced that all the 5xJ tubas used the same bell, which is a bell from an old King Eb Monster, or something like that. They are formed on the same mandrel, but trimmed and rolled to different diameters.

That doesn't mean they are truly identical from example to example, but I would think any reasonably competent technician could fit a replacement with not much effort.

Rick "yes, Matt Walters would know" Denney

Call Dillon's and ask Matt, since he developed the prototype for Conn/Selmer, he will be able to provide the difinitive answer.

I think you will find that you can make the swap perfectly.
Based on the proportions of the bell and flair, my guess is that the 52J bell is approx 1/2 inch shorter than the 56J and the 54J is 1/4 inch shorter than the 56J. I would think that the leadpipe mounting points should be identical across the series.

Good luck with the continued mods and post some pics!!!!

Yes, the 18" 52J bell, 19" 54J bell, and the 20" 56J bell come off the same mandrel. If they cut the bottom off at the same spot, then it should fit your tuba just fine. However, years ago they had some "B-stock" bells that were cut too short and would just barely fit inside the bottom bow ferrule. Make sure you know what you are buying. The original bell was about 19.25" and came from a World War One vinatge King (H.N. White) Eb tuba.

If you make the switch, please send me a PM or e-mail re: your 20" bell.

The OP obviously has customised his 56J, an approach I often have taken myself especially in ergonomic matters.

If the replacement 18” has the right dimensions at the narrow end, I would investigate the options for having these two contrasting bells of 18” and 20” made exchangeable by using some clamping system in stead of soldering for the mounting.

The 18” bell may solve some problems, but there will be situations where the 20” may be missed.

Klaus

imperialbari wrote:The OP obviously has customised his 56J, an approach I often have taken myself especially in ergonomic matters.

If the replacement 18” has the right dimensions at the narrow end, I would investigate the options for having these two contrasting bells of 18” and 20” made exchangeable by using some clamping system in stead of soldering for the mounting.

The 18” bell may solve some problems, but there will be situations where the 20” may be missed.

Klaus

This here is a great idea and most likely not too hard to do.