TromboneChat

I have now collected my little Bach family of horns, a MV 16 (great), an early Corp straight 36 (also great), a mid-70s Bach 50 (this horn really sings, its original dependent set-up soon to be replaced), and now, a Corporation Bach 42 (seems like a red-brass bell) with a stock rotary valve, a 42 slide and main tuning slide from another 42, and a bunch of press-in leadpipes.

I note for you Bach sleuths that the main tuning slide stocking to goes into the neackpipe is kind of a loose fit, and all the leadpipes go in a bit too easily as well: none of these are moving around or rattling, per se...

The horn just seems very bright, and simultaneously, strangely non-resonant, and when I use my Bach 50 slide on this 42, it's not any better.

I got all these components at a reasonable price, so there's some budget to fiddle with this horn: Assuming this is an avenue worth pursuing, and there's a component or sloppy assembly to blame, who would you recommend to send the horn to to see about what might be done to calm it the Hell down?

Is there a way for the right brass tech/exorcist to determine what can be done to improve the horn, or should I just be grateful I'm batting .750?

Plenty of Bachs out there like that. Could be better with a reassembly, could be a bad bell, etc. Having owned 50+ Bachs, they're not all worth saving.

Yes, this seems to be the consensus, anyone out there who can get to the bottom of this, including a considered medical opinion that "your Bach just sucks?"

You can have someone else play it!

Loose fit tubes, either of the tuning slide or leadpipe variety, are not a good start. Fortunately both can be fixed by a decent tech. Once those are correctly fit, if the problem persists, check for leaks anywhere else on the horn.

Burgerbob wrote: ↑Fri May 02, 2025 10:00 am You can have someone else play it!

There's no doubt anyone with a decent embouchure and ears will reach the same conclusion, unfortunately nobody close to me who fits that description.

Was thinking more of a brass tech who can say "there is nothing I can do short of major surgery to take your horn from "dud" to "stud" (you know, in that cheesy, glib chatter brass techs are well-known for).

I will say that if that's what you want, but I may have trouble with the cheesy, glib part.

Send it to SweeneyBrass they will rebuild and it will play 100 times better.

hornbuilder wrote: ↑Fri May 02, 2025 1:25 pm I will say that if that's what you want, but I may have trouble with the cheesy, glib part.

Give it to me straight, Doctor!

In terms of just how loose the main tuning slide is, if you insert only the lower leg (into the neckpipe) and point the bell up, the tuning slide falls right out.

Yeah, that slide tube is leaking.

Put some really heavy grease on it, and play it. Did it make a difference?

Thanks! Never had that one before....

The main tuning slide is from another instrument, not sure if the culprit is a "too small" leg on the slide or a too big receiver on the neckpipe, the only reason I can think of for caring is if I want to try out a copper tuning slide from Hoelle, which works exceptionally well on the Bach 50

The heavy grease is not a fix, it is simply a diagnostic tool.

The fix is to burnish the inner tube to expand it to fit correctly. ( I am assuming the current tolerance is within burnishing range. It may be better to replace the tube, if the difference is too large)

As to the Hoelle slide, that would be another hurdle to address if/when you have it in hand.

I suppose that there are two possibilities for such a problem:
1. Too narrow inner tube, or
2. Too wide outer tube.
If it's possible, try to find other 42's tuning slide and check how it works. If it sits correctly the problem is with inner tube. If not - problem is with outer tube.
BTW, there is possibility that Hoelle's tuning slide won't fit too because of it.

Try your 36 tuning slide in the 42.

In theory, they are the same part.

Dennis wrote: ↑Sat May 03, 2025 10:35 am Try your 36 tuning slide in the 42.

In theory, they are the same part.

Great catch! Yeah, the 36 tuning slide in the Bach bell section is not super loose, fits nice and tight... seems to be the lower leg of the Bach tuning slide, not the receiver on the neck pipe...

The lower leg on the 36 tuning slide is about 3/16" longer than the receiving tube on the neckpipe (propably has a better name, female ferrule, maybe?), but otherwise fits nice and tightly.

Will test play this afternoon after a concert (don't want to confuse my Bach 50 chops...)

Great thing about the 36 and 42 compatibility, just need to buy a single Hoelle copper tuning slide for both the 36 and 42!

Mr. Impulse Control couldn't help himself: Tried out the horn, it's definitely better...

It still sounds like it's leaky, and while the f-tuning slide is very tight, is it possible for the valve itself to be leaking? If so, how to test for this? I note that, with the valve not engaged, I can still easily move the f-tuning slide, comes across as bad compression, assuming this is "a thing."

The F tuning slide should move, but it should also give an audible pop when you press the valve after moving the slide. If not, it may be leaky.

It does pop...

I lack the skills to run down a list of suspects to determine if this is a good horn with poor assembly and/or worn/misfitting components, or just a turkey.

Trouble is, all the really good techs seem to have really long waiting lists, and I don't want to send the bell to someone who cannot properly diagnose it.

Burgerbob wrote: ↑Sun May 04, 2025 9:39 am The F tuning slide should move, but it should also give an audible pop when you press the valve after moving the slide. If not, it may be leaky.

undercaffeinated... it pops when I pull it out, will try it your way...

Burgerbob wrote: ↑Sun May 04, 2025 9:39 am The F tuning slide should move, but it should also give an audible pop when you press the valve after moving the slide. If not, it may be leaky.

Sorry, being dense here: Do you mean after moving the F tuning slide?

JTeagarden wrote: ↑Sun May 04, 2025 10:14 am

Burgerbob wrote: ↑Sun May 04, 2025 9:39 am The F tuning slide should move, but it should also give an audible pop when you press the valve after moving the slide. If not, it may be leaky.

Sorry, being dense here: Do you mean after moving the F tuning slide?

Yes, leave the valve as it, move the slide, then press the valve. It should make some sort of pop.

JTeagarden wrote: ↑Fri May 02, 2025 6:22 pm In terms of just how loose the main tuning slide is, if you insert only the lower leg (into the neckpipe) and point the bell up, the tuning slide falls right out.

As @hornbuilder says, heavy grease is a diagnostic tool, but I've found that Ultra-Pure Heavy Slide Lube works well on one of the tuning slides on my baritone which is a tad loose. I get a really good seal (as proved by the 'pop' when I pull it out), and it stays in the correct place. That being so, I'm not inclined to spend a lot of money on a mechanical repair which is not really necessary.

In your case, however, it might be worth trying that lube on your tuning slide, to see what effect (if any) it has on the sound. If the heavy lube brings about a significant improvment, then itmight be worth taking it to a repair shop, or buying another slide. If the heavy lube gives a stable seal on both legs of the tuning slide, but there's no significant improvement in sound, that would suggest that the problem is somewhere else - and you've saved the cost of a less than essential repair.

That way, if you do track the problem down to another part of the instrument, you've got that more more cash to pay for the fix which really is needed to solve the problem.

HTH, and best regards,
Jack

Burgerbob wrote: ↑Sun May 04, 2025 10:15 am

JTeagarden wrote: ↑Sun May 04, 2025 10:14 am

Sorry, being dense here: Do you mean after moving the F tuning slide?

Yes, leave the valve as it, move the slide, then press the valve. It should make some sort of pop.

Resounding pop when I do this with the Bach 50, very tiny one on the 42, might be part of the problem? The horn has some wonky partials (very unstable...)

How does it play with your 50 slide?

Much worse! Wonkier still ...

more diffuse, less stable, no pitch center

Probably not the slide then. Interesting

valve alignment?

Don't know how to check (other than look for the notches you sometimes see on the rotar to show spindle and rotar alignment)

On this measure, the valve is perfectly aligned...I also restested for compression as Aidan suggested, and actually getting a decent pop if I enage the valve, pull the f slide all the way out, disengage the valve, push the f slide in, and then engage the valve.

Might be the loose push-in leadpipes? All other removable leadpipes I every had, there was no real wiggle room between the end of the lead pipe and the inner surface of the top oputer handslide tube, here, there most certainly is...

But as I note above, the Bach 50 handslide didn't improve things, maybe should re-try now that the Bach 36 main tuning slide takes care of the one leak.

Maybe try the 42 slide on the Bach 50...

Another test is to put really heavy oil in the rotor. This will.makw the rotor "very" slow, but will indicate if the valve is leaking.

Another option. Pull.out the main and F tuning slides. Put your finger over the main tuning slide receiver to close it. Put the bell section under water, and blow into the handslide receiver. If air bubbles from the F valve tubes, it's leaking.

Matt,

If there's any way for you to squeeze this in in say the next 4 weeks, would love to send it to you!

/s/
(nearly) hornless in Seattle

hornbuilder wrote: ↑Sun May 04, 2025 1:39 pm Another test is to put really heavy oil in the rotor. This will.makw the rotor "very" slow, but will indicate if the valve is leaking.

Another option. Pull.out the main and F tuning slides. Put your finger over the main tuning slide receiver to close it. Put the bell section under water, and blow into the handslide receiver. If air bubbles from the F valve tubes, it's leaking.

Yep, tried the second test in the kitchen sink filled with water, steady stream of bubbles coming out the lower f slide receiver when tested this way.

JTeagarden wrote: ↑Sun May 04, 2025 5:02 pm
Yep, tried the second test in the kitchen sink filled with water, steady stream of bubbles coming out the lower f slide receiver when tested this way.

So, at least one of the problems is found...

Yep, assuming that's it for air leaks (not sure there's anything left in terms of air leaks, as the Bach 36 main tuning slide fits tightly, isolating the leak in the f valve, and the fact that my perfectly good BACH 5O slide doesn't make the horn sound any better), I assume the only remaining bell side issues are 1) faulty assembly of some kind, and/or a turkey of a bell?

For these, it is further reasonable to assume that the only way to determine this is to dissemble and re-assemble? No thumping of trained fingers against the bell rim to determine the bell's quality?

You're over thinking this. Many do. Get another 42. After you've spent hundreds of dollars trying to fix it you'll have saved money by buying another. Try before you buy.

WGWTR180 wrote: ↑Mon May 05, 2025 7:22 am You're over thinking this. Many do. Get another 42. After you've spent hundreds of dollars trying to fix it you'll have saved money by buying another. Try before you buy.

Might be doubling down on a bad investment, it is true, but I really like the idea of saving it, I like to imagine that Bach made consistently good components, but maybe didn't do so great in the assembly department, how else to explain some occasionally great horns, and some duds as well?

It was a manufacturing process, after all, supposedly they took the same raw inputs, and undertook the exact same steps with each? The idea of Vincent Bach just getting very, very lucky every now and then just seems so implausible!

I have $700 into the bell section, and $800 into the slide, which comes with 5 different leadpipes, willing to put another $600 to demystify it, at these amounts, am I throwing good money after bad?

Unless you're really attached, I'd probably start over myself.

OK, will heed the advice, not attached, just dogged by temperament...

Maybe will have the Bach 42 main tuning slide leg expanded to fit the section properly, see if there's a relatively cheap repair associated with the f-valve leak, give it one final go, and if still not doing it for me, pull the plug on the bell section...

Maybe the excellent cosmetic condition of the horn and its not having a main tuning slide should have been red flags: Good horns manage to get played,and show their age, bad ones don't, and don't get tuning slides replaced.

Fwiw, the bell I use now is from a corp horn that has a borked valve section.

It is hard to say that you should start on a path of many hundreds when you can look up and see many 42s for $1K; several which presumably have no issues. That said, unless you can try those all and validate, you run the same gamble for getting a good horn with them.

That all said, I generally undertake to fix these horns in my grasp. But I do the fixes mostly myself so that saves me money on everything but parts. Will you be able to sell for a profit? Probably not. See the cost of decent 42s above. Will it still be less than a new Shires? Probably. Will you enjoy it more than a new Shires? I can’t answer that for you. I do, and as a manufacturing person I enjoy doing the work. Just was messing with another valve section for my 42 family this weekend. I went more backwards than forwards, but that happens sometimes.

Cheers,
Andy

JTeagarden wrote: ↑Mon May 05, 2025 7:34 am ….
It was a manufacturing process, after all, supposedly they took the same raw inputs, and undertook the exact same steps with each? The idea of Vincent Bach just getting very, very lucky every now and then just seems so implausible!

Just to touch on this… go watch the process. Many steps in making a horn; if you look closely, particularly at the Bach plant, I doubt two horns ever have the “exact same” steps. The measurements in process are crude and feedback to the operator are terrible. They’re not like a simple turning operation where you can take a repeatable measurement and make it bigger or smaller. Did the seam roll well? What do we measure, how do we know? They try, but they do a lot of fascinating old processes that I don’t think we honestly know what is good or bad for our ‘magic’ sounding horns versus the rest. So, we get lucky a lot.

Cheers,
Andy

JTeagarden wrote: ↑Mon May 05, 2025 7:48 am I have $700 into the bell section, and $800 into the slide, which comes with 5 different leadpipes, willing to put another $600 to demystify it, at these amounts, am I throwing good money after bad?

Projects are experiments. They may work or they may not. My favorite comment through the years, Not yours, has been "I really love the way my horn plays, but, has anyone ever.......(fill in the blank).

elmsandr wrote: ↑Mon May 05, 2025 11:27 am go watch the process. Many steps in making a horn; if you look closely, particularly at the Bach plant, I doubt two horns ever have the “exact same” steps. The measurements in process are crude and feedback to the operator are terrible. They’re not like a simple turning operation where you can take a repeatable measurement and make it bigger or smaller. Did the seam roll well? What do we measure, how do we know? They try, but they do a lot of fascinating old processes that I don’t think we honestly know what is good or bad for our ‘magic’ sounding horns versus the rest. So, we get lucky a lot.

Wow, how does Yamaha produce with so much uniformity in their horns? Have they automated a lot of steps that everyone else still does by hand, and/or mostly by feel?

If so, this suggests that either 1) Yamaha cannot develop a repeatible manufacturing process that produces uniformly great horns, or more likely, 2) Yahama's definition of what constitutes a great horn has to thread the needle between a highly varied view on what constitutes a a great horn, and ends up with a kind of "middle of the fairway" horn that is neverthless not everyone's perfect horn.

If the latter is true, this further suggests that the qualities I seek in a Bach that works for me (given what seems to be a wide variation in how Bachs play) are not necessarily the qualities someone else seeks in a Bach, so "your amazing Bach" may not be "my amazing Bach."

Yamaha has very precise manufacturing processes/techniques. They have put a lot of money into their processes to eliminate, as much as possible, the variations in part geometry that are common in some other brands.
But at an even simpler level, it is doing things like cutting the ends of parts square, so that there are no gaps between tubes underneath ferrules. Also, ensuring that things like tuning slide crooks are correctly inserted into their ferrule/receivers. It is "quite" common that tuning slide crooks are not inserted equally/square into their receiver ferrules! With every conversion project I do on factory Bach's, the first thing I do is pull the tuning slide apart and rebuild it, ensuring the ends of the crook are square, and that the tubes are correctly parallel/straight. That same approach applies to the rest of the assembly. I do agree with you about the idea that Bach parts are fundamentally sound, but they do take some remedial work to get them to where they really need to be.

JTeagarden wrote: ↑Mon May 05, 2025 3:05 pm ….
If the latter is true, this further suggests that the qualities I seek in a Bach that works for me (given what seems to be a wide variation in how Bachs play) are not necessarily the qualities someone else seeks in a Bach, so "your amazing Bach" may not be "my amazing Bach."

Welcome to my resistance. Being that we cannot accurately or consistently define in a repeatable, measurable way what a “dark” sounding horn is, I completely agree that we don’t agree on what an amazing horn is. I’ve always wanted to have a stable of horns with one that I like better than the others but some variability and see if players can identify the horns different from each other. Like an attribute gage R&R if you are an engineering type. I doubt anybody on the planet could pass on either repeatability (can you identify them accurately in repeated attempts) or reproducibility (do you and I agree on the ratings). But this is a terribly boring and long discussion that derails on what to do with your leaky 42B. Cheapest option is probably to pick up a replacement 42B. But if you will still want a different valve, you could just draft a different valve section on to this 42B. Like Bill said, it is an experiment. Read the Edwards literature from like 1994 and there will be several pages why that was a PiTA. Also note that they went back to building solid horns. So,,,, I dunno.

Cheers,
Andy

I don't really mind the added cost of cobbling together a horn, I enjoy the process, even if I am not the one doing the work, I always learn something

It sounds like a worn set of parts that could do with a "restoration". However I have found certain horns react and sound completely different with different mouthpieces. Worth a shot...

As plentiful as 42Bs are on the used market, I'd just start over.