TromboneChat

Just got back my Bach 42BO from a clean/repair service. Playing through the valve feels and sounds great, but now it's making a popping sound whenever the trigger is pushed.

It's like a quick puff of air that can be heard coming from the bell opening. It will only occur the first time if I repeatedly press the trigger very quickly. Waiting 2-3 seconds before pressing again results in another pop.

Any ideas? I already made sure it was well oiled, but no idea what else to troubleshoot.

Sounds like it's sealing.

Don't repeatedly press the trigger very quickly?

I have found that venting valves helps to make slurs smoother. A good technician can do this.

Check in with the folks that serviced your horn. More often than not they'll be able to offer more help and a better diagnosis than you'll get on here.

Thanks everyone. I'll email my tech and get his thoughts. Figured I'd check here first on the longshot it was user error or there was an easy fix.

Again... This is not a problem. It means the valve is well lubed and doesn't leak.

Burgerbob wrote: ↑Fri May 05, 2023 8:08 am Again... This is not a problem. It means the valve is well lubed and doesn't leak.

Well, from a playing perspective it is causing a bit of a new problem for me. Trying to slur with the valve is nearly impossible. The pop comes across like a harsh articulation or a hiccup between the notes.

If this is normal for a valve, is it possible there's just too much oil in it that is suddenly causing the pop to be much more noticable?

jbtb wrote: ↑Fri May 05, 2023 8:49 am

Burgerbob wrote: ↑Fri May 05, 2023 8:08 am Again... This is not a problem. It means the valve is well lubed and doesn't leak.

Well, from a playing perspective it is causing a bit of a new problem for me. Trying to slur with the valve is nearly impossible. The pop comes across like a harsh articulation or a hiccup between the notes.

If this is normal for a valve, is it possible there's just too much oil in it that is suddenly causing the pop to be much more noticable?

With a rotor with tight clearances and a good seal, this is inevitable without porting it.

Even with a perfect rotor, nothing will slur perfectly like a thayer.

Burgerbob wrote: ↑Fri May 05, 2023 8:50 am With a rotor with tight clearances and a good seal, this is inevitable without porting it.

Elow wrote: ↑Fri May 05, 2023 8:54 am Even with a perfect rotor, nothing will slur perfectly like a thayer.

Thanks. It's quite possible that my valve was not functioning/sealing 100% properly before the service. That could explain why it plays much better now and how I never really noticed a popping before.

It's something your chops have to adjust to.

This is part of the reason thayers are so popular, the pop is much less noticeable.

It sounds like your technician adjusted the bearing plate and made it so that the rotor has no lateral play. In other words, your valve was probably not sealing correctly prior to the service. When I do this service, most players feel like the sound centers better and has more core, when the valve is both engaged and disengaged.

Chances are that you will adjust to this and the good will outweigh the bad. My recommendation is to play it for several weeks and see how you feel about it after that.

Crazy4Tbone86 wrote: ↑Fri May 05, 2023 6:39 pm It sounds like your technician adjusted the bearing plate and made it so that the rotor has no lateral play. In other words, your valve was probably not sealing correctly prior to the service. When I do this service, most players feel like the sound centers better and has more core, when the valve is both engaged and disengaged.

Chances are that you will adjust to this and the good will outweigh the bad. My recommendation is to play it for several weeks and see how you feel about it after that.

I noticed the bolded part as soon as I got my horn back from the shop. I thought it was from having the bracing changed, but maybe it was fixing the valve as you mentioned.

Fwiw - the loud popping is no longer as prevalent after a few days. It still happens every once in a while, but slurring notes with the valve sounds much better now.

Yes, it’s a little adjustment that not many trombone players know about. As a rotor is used repeatedly for many years, the metal tends to wear at the bearing on the bearing plate side. When this happens the rotor itself can shift slightly from spindle end to spindle end. It only takes a small amount of shift for the horn to loose focus and eventually air compression.

I see it on about 50-60% of the horns (with rotors) that come through the shop. A good technician should know how to address this on any rotary valve. Not a difficult or time-consuming job, but it does take some know-how and experience. I have seen some inexperienced techs take too much metal off the bearing plate and that results in a new set of problems.

Of course, this is just an assumption that your tech made the adjustment on your bearing plate. There is the possibility that your bearing plate was simply loose and was tapped the full way in when reassembled. This brings up another tech topic: Trombone players…….if your bearing plate is loose, don’t tap it in with a metal hammer! Take it to your tech! I have seen several bearing plates that were marred and severely damaged by do-it-yourselfers who used improper tools.