Convert Bach 50K3 to other valves

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BassTromboneEnthusiast
Posts: 1
Joined: Jun 17, 2024

by BassTromboneEnthusiast »

Hello all,

I just joined this forum and I have a question.

I own a Vincent Bach Stradivarius 50K3 bastrombone

The experience I have with the K-valves is that they become heavy and slow in operation.

I am considering an modification to other valves (Hagmann, Laetzch, Rotax).

Anyone suggestions?

Thanks for your response.

Regards Johan
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BGuttman
Posts: 7368
Joined: Mar 22, 2018

by BGuttman »

For money you can do a lot. But if the only problem with the K valves is that they are getting sluggish, have them looked over by somebody. My main complaint about the K valves was ergonomic (stuck into my neck); otherwise they were pretty good.

If you like the degree of openness of the K valves, you might want to look into axials. Most of us who prefer Hagmanns or other non-Bach rotors is that the axials are too open, but they are very similar to K valves in that respect.

Remember, whatever change you make is irreversible. If you don't like the result you are going to have to live with it.
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elmsandr
Posts: 1373
Joined: Mar 23, 2018

by elmsandr »

Nothing will be cheap, but picking up a decent used set of valves can make it less painful. You have to be careful what type of valve and who you get it from; for example, I would be very skeptical of used thayers from an unknown seller. But from a reputable seller, like say Aiden who recently (maybe still does) have a Thayer set for sale.. that’s where I would look. Personally, I’d probably look for some improved rotors rather than any other design.

That all said, I’d love to take those K valves off your hands… I have a thing for obsolete valves.

Cheers,

Andy
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harrisonreed
Posts: 6479
Joined: Aug 17, 2018

by harrisonreed »

Get the bell and possibly tuning slide mounted to a Shires valve section. A colleague has a horn that is mostly Bach parts but they all work with the Shires "core". He sounds awesome on it.
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elmsandr
Posts: 1373
Joined: Mar 23, 2018

by elmsandr »

[quote="harrisonreed"]Get the bell and possibly tuning slide mounted to a Shires valve section. A colleague has a horn that is mostly Bach parts but they all work with the Shires "core". He sounds awesome on it.[/quote]
This isn’t terribly difficult from where you are starting, you need to reverse the tuning slide and move the main bell flange. You can get some parts from Shires to make the mounts compatible. Then there are lots of valve sections available. But it won’t be inexpensive overall.

Cheers,

Andy
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hyperbolica
Posts: 3990
Joined: Mar 23, 2018

by hyperbolica »

Honestly I'd sell the K and get something set up the way you want. The K valves are kind of interesting, and there are people willing to buy horns like that as a collector or out of curiosity. There are so many other 42 setups out there, that you can probably find something you like that already exists, and the transaction will be close to a wash. A valve set and the work to replace it will be the price of a nice used horn. Even more than the money to convert will be the time. Finding a good tech with time available might be the biggest hurdle.
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BGuttman
Posts: 7368
Joined: Mar 22, 2018

by BGuttman »

Psst -- OP was talking about a 50. But your comment is still correct.
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hyperbolica
Posts: 3990
Joined: Mar 23, 2018

by hyperbolica »

[quote="BGuttman"]Psst -- OP was talking about a 50. But your comment is still correct.[/quote]

Ok, a 50 then. Maybe even more odd and thus collectible, and even more reason to keep it whole. It's always tempting to fix what you have, but after pricing things out a couple of times, and variable experiences with techs, I'd go for something that already exists.
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WGWTR180
Posts: 2152
Joined: Sep 04, 2019

by WGWTR180 »

Shires valves on anything but a Shires-meh...
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jonathanharker
Posts: 139
Joined: Aug 14, 2022

by jonathanharker »

[quote="BassTromboneEnthusiast"]The experience I have with the K-valves is that they become heavy and slow in operation.[/quote]

Having owned a 50K in the past, I found they play very nicely, but there are two things about them:

1. they are often poorly aligned from the factory, so they leak, or feel stuffy. God only knows why Bach can't get that together before they ship them, but what can you do. Get a technician to align them for you, it will make a big difference.

2. they are thirsty for oil, compared to a standard rotor, because they are vertical when playing, so the oil tends to drain to the bottom, and they have a larger surface area. Give them a good clean and load 'em up with oil, you might be surprised.
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bassboneman69
Posts: 290
Joined: Aug 15, 2018

by bassboneman69 »

Johann

Aiden Richie - BurgerBob posted stuff on this horn. I would exhaust all options before cutting up a good trombone.

Especially if the valves are just misaligned.