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Conn 10J Valve Springs
Posted: Wed Oct 01, 2025 3:41 pm
by Richard III
I'm looking for replacement springs for my 10J. Specifically, I would like it if the springs "locked" into the bottom caps like my bottom sprung Conn trumpet's springs do. On my 10J, I get noise from the springs moving around.
Re: Conn 10J Valve Springs
Posted: Wed Oct 01, 2025 5:06 pm
by bloke
Does the bottom cap feature an indention?
If "yes", can you put calipers on its diameter?
Otherwise, it it's a riser (and the spring fits OVER it, still: diameter...
...and identify which and maybe a NOT-way-too-zoomed-in picture.
Re: Conn 10J Valve Springs
Posted: Tue Oct 07, 2025 4:33 pm
by Richard III
IMG_2253 by
genevie7, on Flickr
There is nothing for the spring to attach or wedge to. All the springs for my trumpets that are bottom sprung, are wider at the bottom and match the bottom caps.
Re: Conn 10J Valve Springs
Posted: Wed Oct 08, 2025 10:04 am
by bloke
Okay as long as there's not any sharp fitting area in the bottom cap...
10J pistons and casings are pretty similar to the standard Elkhart production Conn sousaphone pistons, other than the porting of them.
Have you tried the really common long/large diameter springs that are really common and made for Conn sousaphones?
Most busy repair shops have a whole ton of those (used and perfectly fine) laying around...
If the ones described just above have too many coils and make a crunch sound, probably Yamaha tuba springs would work just fine.
Re: Conn 10J Valve Springs
Posted: Wed Oct 08, 2025 1:05 pm
by Richard III
Good thought. But the sousaphone springs are the same diameter as what I have, which is 19mm. What I really need are springs that are 29mm at the bottom and 19mm at the top. The larger bottom of the spring locks the spring into the cap, like with my Conn trumpets. That way there is no movement or shifting during use. I'm guessing that simply does not exist because all searches I've done shows no tuba or sousaphone springs with that configuration. It would seem Conn never thought of doing something like that. Odd since they do it for trumpets and cornets.
Re: Conn 10J Valve Springs
Posted: Wed Oct 08, 2025 1:28 pm
by bloke
Richard III wrote: Wed Oct 08, 2025 1:05 pm
Good thought. But the sousaphone springs are the same diameter as what I have, which is 19mm. What I really need are springs that are 29mm at the bottom and 19mm at the top. The larger bottom of the spring locks the spring into the cap, like with my Conn trumpets. That way there is no movement or shifting during use. I'm guessing that simply does not exist because all searches I've done shows no tuba or sousaphone springs with that configuration. It would seem Conn never thought of doing something like that. Odd since they do it for trumpets and cornets.
I don't believe that exists. I know what you're talking about...the old small-bore Conn trumpets (with the most expensive of those being the "Connstellation").
Once tuba/sousaphone springs are in the center, there's no real force encouraging them to shift sideways, as the center (with the center of the bottom cap being low) is the most relaxed position.
Re: Conn 10J Valve Springs
Posted: Wed Oct 08, 2025 2:07 pm
by Richard III
I get it. Thanks for your help. I've never thought about it but one of my springs shifted and got noisy. I'll be more careful with the positioning.
Re: Conn 10J Valve Springs
Posted: Wed Oct 08, 2025 5:26 pm
by bloke
Richard III wrote: Wed Oct 08, 2025 2:07 pm
I get it. Thanks for your help. I've never thought about it but one of my springs shifted and got noisy. I'll be more careful with the positioning.
The later Conn caps (unless yours was made late enough to be this later simpler style) were much less elegant and didn't have a slope down to the middle. They were simply flat on the inside.
If you would like to improve your lot and have a friend with a lathe and some skills, if they have an end mill that is maybe a half millimeter larger diameter than your Conn springs, they could go into your three bottom caps and cut out a relief in which the springs could rest.
Re: Conn 10J Valve Springs
Posted: Sat Oct 18, 2025 9:43 pm
by York-aholic
Something like this? Says "Valve Springs, Genuine Conn 52J, King 1150, 1151, Tubas, set of 4"
https://www.ebay.com/itm/276655159227?_ ... R5Dcuai_Zg
Re: Conn 10J Valve Springs
Posted: Sun Oct 19, 2025 8:03 am
by Richard III
Wow. Thanks. I am ordering them now.
Re: Conn 10J Valve Springs
Posted: Sun Oct 19, 2025 8:22 am
by York-aholic
@Richard III
I don’t know if those are right for your Conn. A Conn 52j essentially has King valves which have a diameter of approximately 15/16”. <— not precise, only measured with tape measure to try to tell you before you order…
Re: Conn 10J Valve Springs
Posted: Mon Oct 20, 2025 7:57 am
by Richard III
York-aholic wrote: Sun Oct 19, 2025 8:22 am
@Richard III
I don’t know if those are right for your Conn. A Conn 52j essentially has King valves which have a diameter of approximately 15/16”. <— not precise, only measured with tape measure to try to tell you before you order…
Tope, the company that is selling them has the specs on their website. While the fit may not be perfect, it is close enough that they may work. The bottom of the springs are 32mm in diameter and I measured the inside of my bottom caps at 29mm. We will see.
Re: Conn 10J Valve Springs
Posted: Mon Oct 20, 2025 8:08 am
by arpthark
Hope you find something that works. I’ve been interested in those sort of “form fitting” springs but I suppose it really depends on the model and the piston diameter.
Any update on those kids locked in that tower?
Re: Conn 10J Valve Springs
Posted: Mon Oct 20, 2025 11:45 am
by bloke
Find some brass discs (perhaps .6mm thick) on the internet that are just the right diameter to fit inside your bottom caps after determining by measuring.
With a soldering iron, solder your OEM Conn springs to the centers of those discs AFTER you punch holed in the centers of those discs.
Re: Conn 10J Valve Springs
Posted: Thu Oct 23, 2025 1:27 pm
by Richard III
Update on the new springs. The lower portion compresses and just snaps into place in the bottom caps. Thanks so much for this suggestion.
IMG_2261 by
genevie7, on Flickr