Valve Conversion Risks
- Wayne
- Posts: 12
- Joined: Mar 22, 2025
I play an at least 35 year old Bach 42B that I enjoy very much, but it has that very tight F attachment section. Am I risking the rest of the playing characteristics if I decide to get an open valve conversion done? (Attach a Thayer like valve and wrap section for example.)
- Bonearzt
- Posts: 833
- Joined: Mar 22, 2018
ANY work done, especially a full valve install & rebuild WILL change how the horn responds.
But along those lines, I've found that rebuilding older Bachs to remove stress in the valve section GREATLY improves the horn! Even without changing the valve.
But along those lines, I've found that rebuilding older Bachs to remove stress in the valve section GREATLY improves the horn! Even without changing the valve.
- Kbiggs
- Posts: 1768
- Joined: Mar 24, 2018
[quote="Bonearzt"]ANY work done, especially a full valve install & rebuild WILL change how the horn responds.
But along those lines, I've found that rebuilding older Bachs to remove stress in the valve section GREATLY improves the horn! Even without changing the valve.[/quote]
+1
You could also try modifying the valve core—I think it used to be called “boring out.”
But along those lines, I've found that rebuilding older Bachs to remove stress in the valve section GREATLY improves the horn! Even without changing the valve.[/quote]
+1
You could also try modifying the valve core—I think it used to be called “boring out.”
- TomInME
- Posts: 315
- Joined: Jan 03, 2024
There's a better option than boring out now - it's called "3d printing".
- tbonesullivan
- Posts: 1959
- Joined: Jul 02, 2019
[quote="Kbiggs"]You could also try modifying the valve core—I think it used to be called “boring out.”[/quote] opening up the valve ports is a pretty standard mod for the Bach 42B. I believe the gooseneck can also be swapped out, but if you are that far in, might as well just replace the valve with something better.
- brassmedic
- Posts: 1447
- Joined: Dec 14, 2018
I put a Thayer valve on my 42B and I would NEVER go back. Just all improvement. It was great before, but outstanding with the Thayer install.
EDIT: It was open wrap originally. What made.it great was not open wrap, but the Thayer install, and a lot of that might have to do with the more open neckpipe.
EDIT: It was open wrap originally. What made.it great was not open wrap, but the Thayer install, and a lot of that might have to do with the more open neckpipe.
- brassmedic
- Posts: 1447
- Joined: Dec 14, 2018
I put a Thayer valve on my 42B and I would NEVER go back. Just all improvement. It was great before, but outstanding with the Thayer install.
- Wayne
- Posts: 12
- Joined: Mar 22, 2025
Thanks, now it's down to sourcing parts and finding a tech to do the work in Canada (Toronto area) hopefully. I don't really want to ship my horn cross border. {just the hassle}
- elmsandr
- Posts: 1373
- Joined: Mar 23, 2018
Always risks to cutting into a horn, even if it is just different, that might be a problem for you. That said, I’ve never regretted getting rid of the standard Bach rotor on a 42 for literally anything else, almost no matter how silly. (Even the old Holton Monster valve plays and sounds better in some ways).
Before you buy a Thayer like item; play a couple and see if you like it. I love the blow of a Thayer tenor.. But with even the minor maintenance requirements, I’d rather try a couple of other more improved rotors if I were doing it again.
Cheers,
Andy
Before you buy a Thayer like item; play a couple and see if you like it. I love the blow of a Thayer tenor.. But with even the minor maintenance requirements, I’d rather try a couple of other more improved rotors if I were doing it again.
Cheers,
Andy
- muschem
- Posts: 372
- Joined: Jan 17, 2021
[quote="TomInME"]There's a better option than boring out now - it's called "3d printing".[/quote]
Pete Edwards is doing some very interesting stuff in this area. I understand that Pete can 3D print stainless steel CAIDEX-like valve cores and lap them to fit existing valve casings. A core replacement is a neat and easily reversible modification that doesn't require torch work. Doing a core-only mod is also less costly compared to a full valve replacement, but you won't get the potential benefits of stress-relief and the opportunity to change/improve the gooseneck and other parts, which come along with a good rebuild. Potential benefits either way.
Pete Edwards is doing some very interesting stuff in this area. I understand that Pete can 3D print stainless steel CAIDEX-like valve cores and lap them to fit existing valve casings. A core replacement is a neat and easily reversible modification that doesn't require torch work. Doing a core-only mod is also less costly compared to a full valve replacement, but you won't get the potential benefits of stress-relief and the opportunity to change/improve the gooseneck and other parts, which come along with a good rebuild. Potential benefits either way.
- Kbiggs
- Posts: 1768
- Joined: Mar 24, 2018
[quote="muschem"]<QUOTE author="TomInME" post_id="292144" time="1767918453" user_id="17474">
There's a better option than boring out now - it's called "3d printing".[/quote]
Pete Edwards is doing some very interesting stuff in this area. I understand that Pete can 3D print stainless steel CAIDEX-like valve cores and lap them to fit existing valve casings. A core replacement is a neat and easily reversible modification that doesn't require torch work. Doing a core-only mod is also less costly compared to a full valve replacement, but you won't get the potential benefits of stress-relief and the opportunity to change/improve the gooseneck and other parts, which come along with a good rebuild. Potential benefits either way.
</QUOTE>
Thanks for the reminders about Pete Edwards and 3D printing.
I can also vouch for the benefits of de-stressing and re-assembly of Bach bell sections.
There's a better option than boring out now - it's called "3d printing".[/quote]
Pete Edwards is doing some very interesting stuff in this area. I understand that Pete can 3D print stainless steel CAIDEX-like valve cores and lap them to fit existing valve casings. A core replacement is a neat and easily reversible modification that doesn't require torch work. Doing a core-only mod is also less costly compared to a full valve replacement, but you won't get the potential benefits of stress-relief and the opportunity to change/improve the gooseneck and other parts, which come along with a good rebuild. Potential benefits either way.
</QUOTE>
Thanks for the reminders about Pete Edwards and 3D printing.
I can also vouch for the benefits of de-stressing and re-assembly of Bach bell sections.
- Boneaphone
- Posts: 14
- Joined: Sep 05, 2018
I had the original rotor on my 42BO replaced with an Instrument Innovations rotary valve. The difference was profound in a good way.
- GabrielRice
- Posts: 1496
- Joined: Mar 23, 2018
Considering you've been playing that Bach for a long time, I would suggest going ahead with an open wrap conversion but sticking with a rotary valve rather than getting a Thayer. It would still be the same instrument with the Thayer, but it would feel quite a bit bigger all over the range.
For my rare tenor doubling, I have a 42B I bought used, and I compared it to other new and used 42s with various valve configurations. It started as a closed wrap and somebody did a nice open wrap conversion, keeping the original valve. Maybe they opened up the ports, maybe they changed the gooseneck - I don't know. What I know is that it was the best 42 on the wall of that store.
For my rare tenor doubling, I have a 42B I bought used, and I compared it to other new and used 42s with various valve configurations. It started as a closed wrap and somebody did a nice open wrap conversion, keeping the original valve. Maybe they opened up the ports, maybe they changed the gooseneck - I don't know. What I know is that it was the best 42 on the wall of that store.
- TomInME
- Posts: 315
- Joined: Jan 03, 2024
It's partly "get what you pay for". Spend a few hundred for a drop-in valve core replacement for a better blow, or spend more than a thousand and get the de-stress also. (for a bass, it's more like $500 vs $2,500)
It also depends whether the horn is worth the extra. If it's a little beat-up or the bell just isn't that great, might not be worth it for a full conversion.
A lesser consideration is time. Valve core replacement is pretty quick, the transit time is the biggest component. A rebuild will be somewhere in the week or two range (plus shipping), I think?
For me, with an older Bach that has taken some hits, a full rebuild wasn't worth the $$, but the valve replacements were a huge value considering the performance increase vs the cost. It might have been nice to get another 20% improvement, but not at 400% greater cost.
But if the bell was a real gem and I had the cash, a rebuild could have been worth it.
It also depends whether the horn is worth the extra. If it's a little beat-up or the bell just isn't that great, might not be worth it for a full conversion.
A lesser consideration is time. Valve core replacement is pretty quick, the transit time is the biggest component. A rebuild will be somewhere in the week or two range (plus shipping), I think?
For me, with an older Bach that has taken some hits, a full rebuild wasn't worth the $$, but the valve replacements were a huge value considering the performance increase vs the cost. It might have been nice to get another 20% improvement, but not at 400% greater cost.
But if the bell was a real gem and I had the cash, a rebuild could have been worth it.
- harrisonreed
- Posts: 6479
- Joined: Aug 17, 2018
Thayer valves are an aggressive change. They are almost too open on either side of the valve -- your whole horn will play very different, maybe for the better, but it will be like a granny smith apple vs a mango. The throw is forever on those things. That said, the Bach 42 is one of the most restricted, tight trombones ever made, so the Thayer might be the best thing you could do to it, "removing the sock out of the slide crook" so to speak. The one 42 horn that I really dug was actually a 42T. I would have bought it and played it as my main ax if I had been looking for a large bore at the time I tried it.
If you mostly like your 42 already, I'd convert to a bigger modern conventional rotor with the Minick wrap and be done with it. That would be like a Granny Smith Apple vs a Fuji Apple. 99% of people will take the Fuji Apple over the other green waxy thing.
If you mostly like your 42 already, I'd convert to a bigger modern conventional rotor with the Minick wrap and be done with it. That would be like a Granny Smith Apple vs a Fuji Apple. 99% of people will take the Fuji Apple over the other green waxy thing.
- Wayne
- Posts: 12
- Joined: Mar 22, 2025
I get your point and will look at some options. I did play a Thayer on a dual bore (47"/6?") Edwards for about 7 years. I loved that feel but was not going to be playing Bruckner with the NYP any time in my future so it was more horn than I needed. I'd like to get that feel of a horn not making legato or creating an even tone through ranges a chore again.
- slidesix
- Posts: 107
- Joined: Jan 03, 2025
Wayne, I think Harrison might be mentioning a simple conversion, like this with Conn:
Thread (36632) Eastlake Conn 88HO - Successful Instrument Innovations Valve Swap
<LINK_TEXT text="viewtopic.php?t=36632">https://trombonechat.com/viewtopic.php?t=36632</LINK_TEXT>
Nice isn't it? I think so. (Not my horn, BTW)
I have a Bach A47I. It has a Bach in-house axial valve similar to 42T or 42AF (more like the latter). The Axial isn't the be-all-end-all. I thought it was going to be MORE OPEN than it is. But this is a sample size of 1, to take this with a grain of salt.
Don't get me wrong. I still think it is a fine horn. I wasn't sure what to expect. I am glad I did get to experience an axial. Back in our time when your 42B was new, I think axials or thayers were the rage. Not sure that is still the case since we have other valve options, like rotors that have vastly improved. So don't discount them. With that said, the axial valve isn't bad. It plays fine. The throw is actually shorter and quicker than I was expecting. Nor does it seem to suck-the-air-out-of-me.
Common advice is normally to buy the full horn you like rather than assemble one from parts. I think that advice is gear towards your thread title here. As it down plays the risk. But might cost more. Often modders will mod more than once, making buying a whole complete horn sometimes safer and cheaper in the long run. but given that the 42B has such an undersized valve to begin with, I'm sure the overall risk is likely low.
Just be aware that you might need to mod more than once to find what you ultimately may want. To keep that in mind that this might be a trial-and-error process. Good luck!
Thread (36632) Eastlake Conn 88HO - Successful Instrument Innovations Valve Swap
<LINK_TEXT text="viewtopic.php?t=36632">https://trombonechat.com/viewtopic.php?t=36632</LINK_TEXT>
Nice isn't it? I think so. (Not my horn, BTW)
I have a Bach A47I. It has a Bach in-house axial valve similar to 42T or 42AF (more like the latter). The Axial isn't the be-all-end-all. I thought it was going to be MORE OPEN than it is. But this is a sample size of 1, to take this with a grain of salt.
Don't get me wrong. I still think it is a fine horn. I wasn't sure what to expect. I am glad I did get to experience an axial. Back in our time when your 42B was new, I think axials or thayers were the rage. Not sure that is still the case since we have other valve options, like rotors that have vastly improved. So don't discount them. With that said, the axial valve isn't bad. It plays fine. The throw is actually shorter and quicker than I was expecting. Nor does it seem to suck-the-air-out-of-me.
Common advice is normally to buy the full horn you like rather than assemble one from parts. I think that advice is gear towards your thread title here. As it down plays the risk. But might cost more. Often modders will mod more than once, making buying a whole complete horn sometimes safer and cheaper in the long run. but given that the 42B has such an undersized valve to begin with, I'm sure the overall risk is likely low.
Just be aware that you might need to mod more than once to find what you ultimately may want. To keep that in mind that this might be a trial-and-error process. Good luck!
- Wayne
- Posts: 12
- Joined: Mar 22, 2025
What I am most worried about is if the sound would brighten up considerably.
I can't play a small bore below .505 and expect anyone else to stay in the same room as me. The sound just blows apart with any force and gets quite edgy.
My Edwards had a bunch of stuff to keep the sound a bit more controlled: extra long lead pipe, extra big and heavy bell and a different alloy tuning slide.
I played an 88H before the 42 and my control in louder playing changed greatly for the better when I moved to the Bach.
I don't need the trigger a lot, but when I do, it such a drag to not be able to make it sound like the rest of the horn. I don't know if fixing the trigger sound would be worth creating a horn that rips apart on me at high volume.
I can't play a small bore below .505 and expect anyone else to stay in the same room as me. The sound just blows apart with any force and gets quite edgy.
My Edwards had a bunch of stuff to keep the sound a bit more controlled: extra long lead pipe, extra big and heavy bell and a different alloy tuning slide.
I played an 88H before the 42 and my control in louder playing changed greatly for the better when I moved to the Bach.
I don't need the trigger a lot, but when I do, it such a drag to not be able to make it sound like the rest of the horn. I don't know if fixing the trigger sound would be worth creating a horn that rips apart on me at high volume.
- Kbiggs
- Posts: 1768
- Joined: Mar 24, 2018
There are aftermarket components that can provide a similar effect to a 42B that you had for your Edwards. However…
Sometimes a horn that plays differently is an opportunity to learn how to play differently.
If your Edwards was designed to keep your sound controlled at loud volumes, and if your experience with a Conn was that it was difficult to control in louder volumes, then perhaps an adjustment to the way you play in louder volumes could help.
Do you notice any changes to your embouchure as you increase volume? What is your soft playing like?
Sometimes a horn that plays differently is an opportunity to learn how to play differently.
If your Edwards was designed to keep your sound controlled at loud volumes, and if your experience with a Conn was that it was difficult to control in louder volumes, then perhaps an adjustment to the way you play in louder volumes could help.
Do you notice any changes to your embouchure as you increase volume? What is your soft playing like?
- Sesquitone
- Posts: 291
- Joined: Apr 25, 2022
[quote="Wayne"]I play an at least 35 year old Bach 42B that I enjoy very much, but it has that very tight F attachment section. Am I risking the rest of the playing characteristics if I decide to get an open valve conversion done? (Attach a Thayer like valve and wrap section for example.)[/quote]
Before you do anything "drastic" and irreversible—like boring out the typically undersized Bach valve or a full conversion to another type of valve, you might try a simple "fix" of the well-known "very tight F attachment" problem. See if you can borrow (from a colleague or nearby music store) a Bach 50 bass-trombone hand-slide, and try that on your 42. Unless your valve is misaligned (or damaged), that will convert your Bach 42B into a good approximation of the Jay Friedman "Chicago" style Bach tenor. If that helps (a lot), you might consider investing in a Bach HS6262LT slide, or (even better, in my estimation) an HS4762LT dual-bore slide. [Or other equivalent slides, like Edwards, that are compatible with your Bach slide receiver.]
Why would this simple fix "work"? On the standard 42B, when the valve is engaged, the sound-path sees a sudden increase in bore size between the slide and attachment, and then a sudden <B>decrease</B> again between the attachment and the beginning of the gooseneck. This tends to distort the second and third attachment harmonics, lowering the second and raising the third: F2 (stuffy) and C3 (uncentered), respectively, in first position. And it can also affect higher harmonics, causing poor tone quality and unreliable attack response. With the matched bore, the attachment is simply an extension of the cylindrical slide bore near the location of the slide-receiver, before the gradual expansion through the gooseneck into the bell. This maintains the natural distribution of all harmonics.
Once the matched-bore slide is affixed, tune the attachment to match the pitch of F3 in first position with and without the valve engaged. The F2 will be clear and well in tune. The C3 will be quite stable. Sub-tenor notes will blend seamlessly down towards pedals.
That should make a big improvement to all attachment notes—without significantly affecting the slide-alone upper register (Mr Friedman praises the "open feel" throughout all registers). You might still need a better valve. Some of the newer (modular) Bach 42 attachments actually use a (slightly modified) Conn 88H valve: the rotors are identical (interchangeable), the only differences are in the knuckle geometry.
.
Before you do anything "drastic" and irreversible—like boring out the typically undersized Bach valve or a full conversion to another type of valve, you might try a simple "fix" of the well-known "very tight F attachment" problem. See if you can borrow (from a colleague or nearby music store) a Bach 50 bass-trombone hand-slide, and try that on your 42. Unless your valve is misaligned (or damaged), that will convert your Bach 42B into a good approximation of the Jay Friedman "Chicago" style Bach tenor. If that helps (a lot), you might consider investing in a Bach HS6262LT slide, or (even better, in my estimation) an HS4762LT dual-bore slide. [Or other equivalent slides, like Edwards, that are compatible with your Bach slide receiver.]
Why would this simple fix "work"? On the standard 42B, when the valve is engaged, the sound-path sees a sudden increase in bore size between the slide and attachment, and then a sudden <B>decrease</B> again between the attachment and the beginning of the gooseneck. This tends to distort the second and third attachment harmonics, lowering the second and raising the third: F2 (stuffy) and C3 (uncentered), respectively, in first position. And it can also affect higher harmonics, causing poor tone quality and unreliable attack response. With the matched bore, the attachment is simply an extension of the cylindrical slide bore near the location of the slide-receiver, before the gradual expansion through the gooseneck into the bell. This maintains the natural distribution of all harmonics.
Once the matched-bore slide is affixed, tune the attachment to match the pitch of F3 in first position with and without the valve engaged. The F2 will be clear and well in tune. The C3 will be quite stable. Sub-tenor notes will blend seamlessly down towards pedals.
That should make a big improvement to all attachment notes—without significantly affecting the slide-alone upper register (Mr Friedman praises the "open feel" throughout all registers). You might still need a better valve. Some of the newer (modular) Bach 42 attachments actually use a (slightly modified) Conn 88H valve: the rotors are identical (interchangeable), the only differences are in the knuckle geometry.
.
- dukesboneman
- Posts: 935
- Joined: Apr 02, 2018
I had my valve removed on my 42BO and had the Olsen Rotary valve from Instrument Innovations put on.
Best thing I could have done for the horn. Plays fantastic and the "F" side is now just as open as the open horn
Best thing I could have done for the horn. Plays fantastic and the "F" side is now just as open as the open horn
- hornbuilder
- Posts: 1384
- Joined: May 02, 2018
Something that has not been mentioned, is the factory gooseneck on the Bach 42. It is just as much of a choke point as the factory rotor valve, being "considerably" undersized for a horn of that size slide bore.