Converting High Pitched Horns

I have a question for all you expert technicians and fiddler-arounders: What is involved in changing a horn from high pitch to low pitch? How hard is it to do? And what is it likely to cost?



I suspect that the answer will be different depending on the instrument in question: I'm thinking of two.



THE FIRST is an ophicleide that turns out to play in the key of C#. I suspect that changing this instrument to low pitch would screw everything else up too, so this horn may never play in modern concert pitch.



THE SECOND is an old Boosey euphonium with a very sweet and full sound. I know these can be converted, but I don't know what's involved or how much it would cost.



Re: Changing High Pitch Horns to "Regular" Pitch

Reply #1 - Jun 29th, 2006,

Changing a high pitch horn to low pitch involves lengthening the instrument. High pitch has changed many times, in many areas. Low pitch generally means A=440, although the first low pitch was A=435, and many low pitch instruments built in the early 20th century were built to this standard. I will assume that you mean A=440.



For a high pitch ophicleide, I would suspect this is impractical. The high pitch C instrument can be lengthened to low pitch C, but then the relationship of all the tone holes will change. For the last (9th, 10th, or 11th key) open key, the key can probably be adjusted down to provide a reasonable pitch once the horn is lengthened, but the rest of the keys (1-n) will then be out of position. Practically, there may be enough room to open the holes of these keys enough to bring them into line, but that also depends on the tone holes not having to be increased beyond the raised sides of the tone holes. It also means ruining the originality of the instrument.



For the reasons of both having to increase the tone holes and changing the original instrument, I would consider these options impractical. I would much prefer considering the transposition different (C#) any time one would use such an instrument.

As far as the euphonium, it depends on whether the tuning slide can be pulled out far enough to meet the low pitch you are playing with. If it cannot, extensions must be made for it so that you can do so. Many instruments built in the early 20th century were built to be configured at standard. In any event, the individual valve slides must also be pulled to a low pitch length, but this is usually not a problem.



If a lengthened tuning slide is needed, once appropriate tubing is located, I would presume that it could be done reasonably.

Reply #2 - Jun 29th, 2006,

I agree with Pryorphone on the Ophicleide. Course the other option there is to find a bunch of other keyed instrument players who also have high pitched instruments!



On the Euphonium, just to add a bit. Lengthening the tuning slide is the most logical place to add more tubing, but it isn't the only option. Sometimes, there are other locations on the horn where additional tubing can be added. And another choice is a long bit to put in between the mouthpiece and the receiver.




Reply #3 - Jun 30th, 2006,

The only other nondestructive way for the Euph would be to have a new tuning slide made (longer) for the instrument. I like being able to convert back to high pitch when I want to. Especially with the electric organs and pianos now that can tune to high pitch.

Reply #4 - Jan 22nd, 2008,

I've had to hire two older brass instruments changed from high to low pitch which I think were done by guess. If US high pitch was a=452 and is now A=440, what length of tubing needs to be added to a BBb tuba or an Eb tuba to bring it down?



I can then figure a Bb baritone and an Eb alto horn as being half as much.




Reply #5 - Jan 22nd, 2008,

I don't like to do them by formula. For one thing, they aren't all 452.



MineralMan

Reply #6 - Jan 23rd, 2008,



Above, you mention that a lot of European import instruments in the early 20th century were made to the A=435 standard. I really wonder if that's what's up with my Czech-sourced New Yorker Euphonium.



It's flat on the open bugle, despite substituting several mouthpieces, and with all slides in. And it's just about that much flat. I can force it up to the A=440 standard, but that's not much fun.



If that's the case, approximately how much tubing would I need to remove to bring it up in pitch. I could work on the main tuning slide, but only have about 1/2" beyond the braces there that could be cut. That would give me only an inch, and I don't think that's enough. More major surgery would really be beyond my capabilities, I think. I could probably pick up another inch by customizing a mouthpiece shank for the horn and working with a shorter backbore. Still, I don't think it would be sufficient.

A lousy 5 Hertz to gain. Maybe I'll have to go to a shallower cup mouthpiece and just force the pitch. It's easy enough to do, especially in the upper partials.



BTW, there are no leaks in the horn, and valves are good.



Reply #7 - Jan 23rd, 2008,

That would be a good reason for these transistor pocket stroboconns to have a digital frequency meter on them instead of just a pointer and a couple of high/low lights. Being able to see exactly the cycles/second change per inch of tuning slide pullout would make figuring the needed change in length much easier.



The change of tubing length per cycles/second is different on each note; for each octave higher half as much length change is needed per cycle. Must be one of them sine/cosine/tangent deals.




Reply #8 - Jan 23rd, 2008,

My 1907 Conn double-belled baritone was built to the 435 "International Standard". I needed to build new main tuning slides (rather than cut the old). I left the valve slides alone, and they were fine.




Reply #9 - Jan 23rd, 2008,

I would not give up on mouthpieces too quickly. Have you tried a bunch of vintage mouthpieces? I have a tuba that was always flat on the several mouthpieces I tried with it, UNTIL I used a vintage mouthpiece of the same brand (York), and wonder of wonders, it is now solidly at 440.



The main tubing slide is the most obvious place to remove tubing, but a shortened mouthpipe, or tubing after the valve engine are also possibilities. . . BUT assuming the horn is in tune with itself now, by shortening the main tube will mean that all the valve tubing is too long, so, they will need to be cut as well. And, usually the inner slide tubing is as long as it can be so that means you will need to cut both the inner and the outer slides.



One other possibility, if you have the space is to cut on the bow side of the tuning slide. It solves a lot of the problems of cutting both inner and outer slides.




Reply #10 - Jan 23rd, 2008,

Thanks for the suggestions. The main tuning slide on this horn is after the valve set. The problem is that there are braces just over one-half inch from the end of the section that would have to be cut, and there is no room to shorten the slide itself.



As for the mouthpiece, I wish I could find the proper vintage piece for this. The receiver is slightly smaller than the standard small shank mouthpiece, which means that a standard mouthpiece inserts only .6 inch. I have not found a vintage piece that fits this smaller receiver.



I have shaved off a bit on one 6.5AL piece's shank, but it is not enough to make a real difference. What I am looking for on eBay is a piece designed for these 1910-20 Czech small-receiver horns. I have seen one there but lost the auction. It is almost 1/2" shorter than modern trombone/baritone pieces. Plus, the diameter at the small end is smaller than that of modern mouthpieces.

Further, the vintage mouthpieces have a more conical shape to the cup. I have one, but it has an even larger shank, so I cannot try it in the horn.



Oddly enough, intonation on the instrument, with the 6.5AL is quite good, which surprised me, since the horn is not a pro-quality one. There is quite a bit of flexibility in pitch, and I can play it in tune at A=440, with only the second line Bb being problematic. I do not need much of a push here, and I'm betting that the mouthpiece that came with the instrument would probably do the job, but that's lost forever.



If anyone has one of these smaller-than-standard mouthpieces and would be willing to loan it out briefly, I could assess the instrument and decide what to do. I do not really want to cut on it unless I absolutely must. The correct mouthpiece would enter a standard receiver right up to the end of the taper. It is too much to remove from a regular mouthpiece, although I'm trying to figure out how to chuck one of mine in a lathe and try to do it if I must.



So, if you have such a piece lying about, and are willing to send it to me for a trial, which would be great. Better would be one you are willing to sell...maybe one you've tried and is a little too small for any of your horns. There were so many of these Czech instruments imported that there must be some mouthpieces out there,