TromboneChat

I've seen some discussion on the forum regarding adjustments to the depth at which a mouthpiece inserts into a leadpipe, with various approaches suggested for fine-tuning this, including a few wraps of teflon tape around the mouthpiece shank. This topic is a bit different. I'm interested in thoughts on holding the mouthpiece-to-leadpipe depth constant, but adjusting the depth at which the leadpipe inserts into the cork barrel on the slide. I'm curious to hear whether others have experimented with this, and what your observations were.

I recently tried this on my Butler C10, and I was a bit surprised at the difference. Not surprised that there was a difference at all, but rather surprised at how positive the difference seemed. Of course, changing anything on the horn (material, dimensions, locations of various components, etc) produces some difference... sometimes good, sometimes not so much. But often, these changes are pretty subtle. Generally, it seems to me that changes closer to the face have larger perceived differences than changes farther out toward the flare. But, despite this change being fairly close to the chops, I didn't expect to perceive a large impact, as the venturi relationship between the mouthpiece and leadpipe remained constant, and I just added a bit of length to the top of the slide essentially.

To adjust the insertion depth, I used a leadpipe thread adapter from Instrument Innovations (https://instrumentinnovations.com/coars ... e-adapter/), the receiver in the cork barrel on the C10 is bi-threaded, so I used an adapter with OD threads opposite to the threads on my leadpipe collar. In this case, the leadpipe I used for testing has fine threads (Edwards/Getzen) on the collar, so I picked an adapter with course outer threads and fine inner threads to fit both the receiver and the leadpipe. The change in insertion depth was around a quarter inch. Multiple adapters could be stacked to extend out further, but I'd imagine you would run into ergonomic issues at some point. Also, making the horn longer changes tuning slightly. If you're already pushed in all the way on your tuning slide, adding length to the horn probably wouldn't work well.

I've seen some adjustable gap receivers (https://www.dwerden.com/forum/entry.php ... p-Receiver) for euphoniums, but as far as I know, those are more similar to adjustments we might make on a trombone for mouthpiece insertion depth - i.e. changing the distance between the mouthpiece and leadpipe venturi.

I haven't ruled out placebo effect, here. A/B testing is always tricky when you can see and feel the difference. Has anyone else tried this? Thoughts?

Generally... 'why'? (Plus you haven't said what the difference was...)

That there'd be some difference isn't weird. You're adding a bit of mass, which you might like much in the same way as a standalone mouthpiece collar... not uncommon.

Also, even fairly small changes in perceived feedback from bell-to-face/ear distance are pretty noticeable. The difference between a 'ballroom' and most non-ballroom bells is between 3/4 and 1", and that's several kinds of obvious. 1/4" might not register very strongly visually, but you'd probably hear it.

ithinknot wrote: ↑Sat Apr 01, 2023 11:24 am Generally... 'why'?

Completely fair question. I read this as "why try it in the first place?", since it seems self-evident as to why it might be interesting to experiment further with something once a positive attribute is observed in preliminary testing. In this case, I was looking for an alternative to having the receiver re-worked on my C10. Some of my leadpipes don't thread in perfectly, and I had been discussing this with Dave Butler. At first, I thought it was a mis-threading issue on the receiver, but after looking at it more carefully and talking with Dave, I think the receiver design is just a very close fit, and some of the collars on my pipes might be just a hair too large (or perhaps not perfectly aligned) to thread down fully without a lot of resistance. So, my initial thought in trying the adapter was just to alleviate this minor issue. I really didn't expect to notice much of a difference in playing characteristics.

ithinknot wrote: ↑Sat Apr 01, 2023 11:24 am (Plus you haven't said what the difference was...)

Yes, I was intentionally trying to avoid influencing the discussion early on with my own observations. If there aren't any other observations from folks who might have tried something similar, I'd be happy to share my experience.

ithinknot wrote: ↑Sat Apr 01, 2023 11:24 am That there'd be some difference isn't weird. You're adding a bit of mass, which you might like much in the same way as a standalone mouthpiece collar... not uncommon.

Also, even fairly small changes in perceived feedback from bell-to-face/ear distance are pretty noticeable. The difference between a 'ballroom' and most non-ballroom bells is between 3/4 and 1", and that's several kinds of obvious. 1/4" might not register very strongly visually, but you'd probably hear it.

These are great points, and I hadn't considered the extra mass or additional set-back vs the end of the flare. I don't have any face time on ballroom style bells, so I don't really have a direct frame of reference for comparison. But, the descriptions I've read of the difference make sense. Thanks for pointing it out.

muschem wrote: ↑Sat Apr 01, 2023 12:31 pm

ithinknot wrote: ↑Sat Apr 01, 2023 11:24 am Generally... 'why'?

Completely fair question. I read this as "why try it in the first place?", since it seems self-evident as to why it might be interesting to experiment further with something once a positive attribute is observed in preliminary testing.

muschem wrote: ↑Sat Apr 01, 2023 12:31 pm At first, I thought it was a mis-threading issue on the receiver, but after looking at it more carefully and talking with Dave, I think the receiver design is just a very close fit, and some of the collars on my pipes might be just a hair too large (or perhaps not perfectly aligned) to thread down fully without a lot of resistance.

If your Instrument Innovations adapters (sans pipe) thread into the receiver ok, I'd assume the receiver threading is fine.

Do you have any issues threading the adapters onto the problem pipes outside of the horn? If not, clean out the inner slide and then try screwing in the pipes without any lubrication. If they get tight early on or there's obviously fluctuating resistance during the first few rotations, it's probably either that the collar is misaligned or the pipe itself is bent - both of which could easily happen. If the threads *are* slightly oversized then a pass or two with the appropriate die would free things up, but I'd have a tech check the truing on a lathe first.

If the pipes work fine with the adapters, and pass the lathe/other horns tests, then of course it's possible that the receiver isn't mounted true to the inner slide, in which case you've got a problem for the maker - though the place that made the mistake isn't always the best place to fix the mistake.

I think there are 2 reasons why this isn't normally done. First, moving where the mouthpiece sits changes the length of the slide positions relative to where your face is, and most players want that to stay a constant. Second, the slide tube is a constant diameter, so I can't see how it would make much difference if the leadpipe goes in or out 1/4". I think it's much more likely that the different playing characteristics you are noticing are either from a leadpipe that is a bit out of alignment with the threads, so is stressed as it is pushing against one side of the inside slide tube, or from the added mass, as already mentioned.

A 1/4" difference might also very well be changing his the mouthpiece sits on your face. The positive difference might be completely related to embouchure angles.

It also changes the placement of nodes all through the instrument. Seems to me that would noticeably effect lots of things.

Doug Elliott wrote: ↑Sat Apr 01, 2023 9:02 pm It also changes the placement of nodes all through the instrument. Seems to me that would noticeably effect lots of things.

Oh yeah, good point!

At one point I thought having my leadpipe out just a little - about 1/4 turn - made the instrument just a bit more friendly. Still slotted well but a little more flexible, yadda yadda. I even had a little solder dropped in to keep it at that spot.

The I got irritated with not being able to pull the leadpipe, had the solder cleaned off, screwed the pipe all the way in again, and decided whatever difference it made was so miniscule as to be insignificant.

You can file this under "dumb things you think about when you work in a trombone factory."