Common Causes of Pitch Problems in Equipment

[cjk]

Leaks.

[Rick Denney]

Leaks.

Yes, and these can be water keys, ill-fitting tuning slides, ill-fitting mouthpieces, and, most of all, worn valves.

But the biggest single determinant of intonation tendencies in an instrument in new condition is the taper design.

Rick "thinking there is nothing inevitable about the harmonic series in a conical instrument" Denney

[iiipopes]

I'll just throw this in: assuming no leaks, part of it is trying to get a horn with conical nature to play in tune by 1) tempering a natural overtone series where the 5ths are by nature a few cents sharp and the 3rds are significantly flat by nature, compounded by 2) adding cylindrical tubing in the valve block, which causes disruption of the conical projection and as a consequence disrupts the overtone series tuning.

Until someone takes the time to put together for tuba, and I know the R & D would be massive in both time and money, the same step-bore research that Schilke did combined with a way to form a Pilczuk-style step bore leadpipe around the bell into the valve block, it is surprising that a tuba, any tuba, ever plays as well in tune as it does!

[windshieldbug]

Usage of inapropriate instrument.

[Alex C]

Ears

[tubatooter1940]

My first school sousaphone had a dead bat down it.

[windshieldbug]

Unexpelled liquid in constricted area.
Sand. (NOT lodged!)
Botanical occurences.

[ASTuba]

I'll just throw this in: assuming no leaks, part of it is trying to get a horn with conical nature to play in tune by 1) tempering a natural overtone series where the 5ths are by nature a few cents sharp and the 3rds are significantly flat by nature, compounded by 2) adding cylindrical tubing in the valve block, which causes disruption of the conical projection and as a consequence disrupts the overtone series tuning.

Until someone takes the time to put together for tuba, and I know the R & D would be massive in both time and money, the same step-bore research that Schilke did combined with a way to form a Pilczuk-style step bore leadpipe around the bell into the valve block, it is surprising that a tuba, any tuba, ever plays as well in tune as it does!

I know that Matt @ Dillon has done some Pilczuk style leadpipes in the past.

Rich Ita, a very close friend of mine, and helluva repair guy, owns the Pilczuk rights, and there were tuba leadpipes made (Gene Pilczuk even had bassoon bocals done in the steps), but alas, Rich doesn't have a machine capable of making/bending these leadpipes.

[Dean E]

What causes (just equipment, not embouchure, breath support, posture, etc.) can you think of that make a brass instrument too sharp, or too flat? All i can think of is tuning slides, inappropriate size mouthpiece, something lodged in the horn or a severe dent, bad hand position for f horn?

I recently had a bad experience with a severely misaligned rotary valve.

The rotor was about 10 degrees off, but I didn't know because I could play--until the cork bumper disintegrated. What an experience that was. The horn is so much easier to play with the correct valve alignment.

Also:

--Wrong mouthpiece for the receiver (big gap, wrong length, and leak because of the wrong taper).
--Bad repairs (wrong tubing length, diameter, and material), for example my old Pan Am helicon with a a piece of copper tubing fashioned to replace the lead pipe.
--missing water key cork

[Donn]

Since the subject came up, here's a pitch problem that has plagued me a little: a baritone that can be played somewhat in tune above Bb in the bass clef, and indeed below that note, but on that particular note itself the pitch drops precipitously, half step or more. I'm not saying it's perfectly in tune elsewhere, but that Bb is conspicuous.

It's an Alexander 4 top piston, unknown model or age, large receiver (largish picture.) I have fiddled around with valve alignment, rinsed it, run stuff through it.

[windshieldbug]

Oboe or violins tune sharp...

[Chuck(G)]

Since the subject came up, here's a pitch problem that has plagued me a little: a baritone that can be played somewhat in tune above Bb in the bass clef, and indeed below that note, but on that particular note itself the pitch drops precipitously, half step or more. I'm not saying it's perfectly in tune elsewhere, but that Bb is conspicuous.

It's an Alexander 4 top piston, unknown model or age, large receiver (largish picture.) I have fiddled around with valve alignment, rinsed it, run stuff through it.

I like the touches of nickel on the bell.

How well does the Bb play if fingered 14?

[iiipopes]

Pilczuk tuba leadpipes? Fantastic. I hope Rich gets there someday.

Pilczuk buffoon, er, bassoon bocals? Should be a required purchase.

[Chuck(G)]

Pilczuk tuba leadpipes? Fantastic. I hope Rich gets there someday.

Why--the "hands-on" reports that I heard were, at best, lukewarm.

[Donn]

How well does the Bb play if fingered 14?

Much better than open. In a recent fantasy that I would use this thing to sub for a missing trombone player, that was going to be one of my tricks to make it work. Then I spent some more time with the tuner and abandoned that idea. It's bad all over, the Bb is just where it comes out and slaps your face.

One thing I have not tried is a leak test - it has been full of water, but not really checking for anything leaking out. Valve
slides seem to make a reasonable vacuum when drawn out.

When I got it, there was some waxy sludge in the valve section, slightly greenish from copper oxide.

I think a previous owner may have been a young student - poor kid!

[MaryAnn]

Alex french horns are known to have widely varying individual pitch tendencies. (i.e., some of them are out of tune and others are fine.) I play tested one around the time I bought my E. Schmid, and that particular Alex 200 was too out of tune for my taste. I don't want to pull slides for every other note, and I don't want to have to move my right hand (in a french horn) for every other note either.

Walter Lawson has a leadpipe design that has inner tapers; (it goes from larger to smaller to larger to smaller, etc, within the external leadpipe; it is a pipe-within-a-pipe) that works extremely well, on horns of other makes as well as his own. Not only are notes in tune but they lock in well, which I think is actually a function of being in tune; if the note happens to "want" to be where you want to buzz it...it will lock in well.

I still think the C problem on F tubas could be fixed by someone who understood leadpipe design. I think Walter Lawson could do it but no one has asked him to. An instrument whose notes lock in well out-of-tune is going to be very difficult to play in tune; one that does not lock in as well but is out of tune will feel much more playable by someone with a good ear.

The bell taper also has a lot to do with how well notes lock in. Same concept, basically. I heard a high level player playtest my Lawson bell on his E. Schmid horn; the sound was about the same as his wide Schmid bell, but it was obvious to both him and me that the fast passages he was using to playtest locked in better with the Lawson. He missed far fewer notes with the Lawson bell than he did with the Schmid bell. I found that fascinating. I'm sure Rick probably has given a more technical explanation somewhere along the line. What we need is for someone to actually get on the tuba leadpipe bandwagon and design some that work really well. They could make major bucks in the rotary bass tuba market.

MA

[Rick Denney]

What we need is for someone to actually get on the tuba leadpipe bandwagon and design some that work really well. They could make major bucks in the rotary bass tuba market.

There has been a lot of experimentation with leadpipes on instruments under development. I don't know how consistent pro-grade french horns are in basic design, but I wonder if they vary anywhere near as much as tubas do. To provide a custom leadpipe for any given tuba would require considerable experimentation that would not translate to other instruments, and I suspect the cost would exceed the acceptable price except in a few cases.

Some tubas have been provided with more than one interchangeable leadpipe for different applications and player preferences.

I recall a picture of Warren Deck experimenting with a (still straight) leadpipe on an early 2165, and I know that he fiddled with leadpipe tapers quite a bit with those instruments. He's not unique.

I'm not sure that the low C on an F tuba is a leadpipe issue. It's not a case of being out of tune--it's a case of having a side slot and not providing the reinforcing resonance that players accustomed to big tubas expect. Changing the leadpipe to repair that might well cause other problems. During the development of B&S F tubas, however, the leadpipes have been a key area of experimentation.

Maybe horns have a consistent leadpipe shape that makes it a lot easier to provide an aftermarket product, even when it's custom made.

Rick "thinking tubas vary more than most instruments" Denney

[Chuck(G)]

To start with, consider the length of a horn leapipe--what, about 30" or so? There's just so much more of it than there is on a tuba.

[MaryAnn]

I dunno on the length of a horn leadpipe. I'll have to go home and measure it. However horns have varying designs...Geyer, Kruspe, this, that, the other, having mostly (to amateur eyes) to do with the valve layout. However I'd guess that there is nowhere near the difference there is in F tubas.

On my F tuba, the C is dramatically sharp and that is why it doesn't want to play on the pitch I want to play it. A friend who has a 182 decided through experimentation that the tuning slide was quite a bit too short. He lengthened it, pushed in his valve slides, and says the entire thing is noticibly easier to play. I haven't done that yet, but my 182 is out on loan and I think the guy who borrowed it may be playing with tuning slide length. If the tuning slide (on mine) really is too short, then that C would become a lot more accessible given how sharp it wants to play now. It's generally easier to lip notes up than down, if you have out-of-tune slots to deal with, well for me anyway. However I'm no acoustician.

MA

[Lew]

I thought that the most common source of intonation problems was the attachment at the end of the mouthpiece.