Favorite valve?

[conn88Hagmann]

In another thread, Sesquitone (Benny) makes the case that the F-attachment tubing I.D. (and valve ports) should be the same as the slide bore.

So that’s what I have on my Conn Elkhart. . . It was a kit from Hagmann in about 2009/10.

Yes, that sounds right. René Hagmann began providing “matched-bore”

Thank you for such a thorough answer! I’m retrieving my matched bore Hagmann Conn 88 from the attic asap!!

[Digidog]

Yes, that sounds right. René Hagmann began providing “matched-bore” valve-plus-wrap kits for individuals and commercial manufacturers in the late 1990s. René and I had worked for a couple of years before that trying to discover the reason for and, if possible, to correct well-known “problems” with attachment notes. I had noticed for some time that, except for short notes in rapid passages, professional tenor trombone players using Bb/F instruments in symphony orchestras usually favoured slide-alone (SA) 6th and 7th positions for the four notes (F2, C3, E2, B2) that theoretically could have been played with the valve. When I asked some local professionals (Jim DeSano, Steve Witser, Paul Ferguson, and my colleague at The University of Akron, Ed Zadrozny) about that, I received fairly uniform “complaints” about those attachment alternates, typically: when the F attachment is tuned so that the attachment F3 matches the SA F3, with the slide closed in both cases, the second attachment harmonic, F2, tends to be flat and “stuffy” (even when the pedal is well in tune), the third harmonic (C3) tends to be very sharp and uncentered, and attack response is unreliable. Most of those players “blamed” the valves available at that time. [The Thayer valve had been invented decades earlier but was not in common use. More advanced valves such as the Willson Rotax and the Hagmann valve were just becoming available.] When I contacted Mr. Hagmann about his valve, he confirmed that he had heard similar complaints—which had been motivating factors in developing his very “open” three-internal-duct design. But even then, the problems remained. Something else was going on!

Two facts gave me an inkling as to what might be causing the “problems”. When I had spoken at length with Allen Kofsky (long-time second trombone with the Cleveland Orchestra), he pointed out a couple of unusual things about his trombone, a modified Benge 190: (i) the attachment had been literally chopped off short to put it in Gb, and (ii) he was using a dual-bore slide, on which the larger bore (14.3 mm) matched that of the attachment. Allen preferred the dual-bore slide because its sound blended well in between the first trombone and the bass. But he never experienced any of the attachment problems others complained about. In fact, he told me, he used the major-third attachment alternates a lot, and rarely used positions beyond SA 4th. The second fact was that my own Olds “Recording” model (that I already had already modified to Bb/G) did not exhibit any of the usual problems. At first, I thought that these two facts had to do with the shorter attachment tubing. Then I realized that the Olds also had a dual-bore slide (again with the larger bore very closely matching that of the attachment). I immediately contacted René and relayed my suspicions that a “matched bore” might fix some of the problems. Thus began a long collaboration trying to solve this puzzle. I was fortunate enough to be able to visit him in Geneva several times on my way to or from international technical conferences in my research field of computational fluid dynamics. René began experimenting with matched-bore Bb/F tenor prototypes of various bore sizes (using his own valves, of course); and I had some prototypes built by modifying Willson tenors in two bore sizes with Rotax valves: replacing the “oversized” F-attachment tubing with smaller matched-bore G attachments. Plus, some other combinations: an Eb/C alto and a C/A tenor (cut down from my already constant-bore Olds).

The results were stunning: all of the usual “problems” immediately evapourated in all cases. Attachment alternates were the full equivalents of their slide-alone counterparts (of the same sound-path length) in terms of intonation, tone-quality and attack response; and those with longer sound-paths were very similar. One Saturday morning, when I was visiting Mr. Hagmann’s shop in Geneva, Andrea Bandini from Orchestre de la Suisse Romande strolled in to chat. René had been demonstrating to me a combination of a Bach 42 bell with standard (14.3 mm) F attachment and one of his own valves, with a lightweight Bach 50 slide—a constant 14.3 mm throughout slide, valve and attachment. He handed it to Andrea, who proceeded to run through some beautiful orchestral excerpts, especially in the low-tenor register using the valve. Andrea was extremely impressed with the uniformity of the response over all registers (even up to the sixteenth harmonic!). Until he looked at the slide and exclaimed, “Mon Dieu, c’est un coulisse de trombone basse!” And handed it back to René like a hot potato, as if this were some kind of Frankenbone. Except for the valve, this was, of course, identical to the LT42BOF developed by Bach several years later (in coordination with Jay Friedman).

As mentioned elsewhere, I published an article in the Spring 1999 issue of the ITA Journal, “Improving Attachment Intonation, Tone Quality and Attack Response”, outlining the results of our investigations. This was met with “mixed” reviews, to say the least. Apparently, it was too far out of the accepted “conventional wisdom” to be believable to some people. [Apparently, I had “stepped on some toes”. I won’t go into some of the nasty personal attacks I received at that time.] Although René and I had only studied matched-bore tenor prototypes, we speculated that something similar would apply to bass trombones, as well. And this was later confirmed by René. In fact, he was particularly concerned about the fact that on an inline dual-valve bass, his constant-bore valves (which are rather bulky) were taking up too much room along the gooseneck, where there should be a gradual expansion. This was a motivating factor for his development of his “progressive-bore” idea, which is only possible with the three-duct design of his valves. The internal ducts are (laboriously) tapered, gradually expanding in the downstream direction, effectively recreating the taper that would otherwise be in a “non-valved” gooseneck.

Of course, people will have a range of experiences with different trombones, particularly with respect to how the attachment is tuned relative to the base Bb instrument. Tuning the attachment F3 sharp can produce a better-in-tune F2—but this places the attachment C3 (and other third-harmonic notes) even further out. And may cause the C2 to be too far beyond SA 7th position to be viable. Conversely, tuning the attachment flat—so that C3 is in tune with the slide closed—probably means that the F2 is unavailable. But now the C2 is well on the slide.

In any case, getting back to the original post, in addition to choosing one of the most “open” valves available today—depending on the external dimensions desired—my advice would be to consider trying the matched-bore principle, especially if the intention is for using attachment alternates, as opposed to filling the tenor gap down to (almost) connect to pedals. In other words: use a smaller-than-conventional bore for the valve and attachment wrap, matched to that of the slide. Making sure that the construction leaves no “gaps” inside ferrules or any other inadvertent discontinuities along the sound-path. And finally (of course), I would strongly advise using the far more facile minor-third tuning for this purpose!

But what you have said, actually means that it doesn’t matter what size the pipes are, matching or not. It’s just how it plays. . Which is fine of course but means no scientific theory at all can be applied.

What I am saying, is that flow is a practical result of testing, wheras the science behind it is a guide to what is purposeful and reasonable to try.

There are so many factors determining the flow and/or resonance in complex systems, that it can be impossible to draw any conclusions of what affects what, and that there - especially - are no standard recepies for making a pre determined impact on them. You can calculate to a certain degree, but for the most part you have to test and when you get the desired results compute backwards to see what has been achieved.

The theory of matching pipe diameters, is only valid in a specific practice of how you assemble certain pipes. There is no scientific evidence or theory that says that it would be a universal solution to any assembly of other pipings, valves or flares. For all science says, it could well be very wise to make the piping insides rough like sharkskin, to facilitate passage of air and increase flow, and that it could be very wise to have valves with significantly larger diameter than the ensuing pipe to increase flow at a point where flow is expected to change when the valve moves.

Note the word "could" here, because science only says what in closed and defined systems, in singular conditions, makes for an effect on the flow, not what combinations of situations and conditions are best practice - because then too many factors with each too large impact works in combination to make the combined system impossible to compute without first testing it.

What @Sesquitone says is that Hagmann did a lot of testing and found a practice that works for the assemblies that the Hagmann workshop does, with the components they use and apply. There is absolutely nothing of the results of that testing that can be applied to the components used by other builders - or probably even the materials used. Everything has to be tested. Change one fraction of a grade to the inclination of the inner diameter of a Hagmann valve, and everything could be upset in a totally unexpected way - forcing the whole process of testing and trying to start anew.

So no: Flow and resonance are not a one-recepie-fits-all. Science clearly says it's much, much more complex and complicated than that.

[imsevimse]

I'm happy with all the horns with attachments I have. Most are old of the brands Conn, Bach, King, Yamaha, Benge, Kanstul, Holton, Schilke, Martin, Edwards, Olds, Selmer and Thomann.
I have only one with thayers and that's an Edwards 350. It's nice. I've also tried several basses with thayers and didn't like them much. I think it's because I'm not used to play that valve. For me they are too open so they suck my air, and I'm not a large person so I need that air. It is more of a problem in the valve register so the thayer on my Edwards 350 isn't much of a problem because there are not many long low notes I need to play in it's low register. The many thayer-basses I tried were all old conn horns converted to thayers and I just felt the original conn character was lost on all of them. I've also tried an inline Shires bass with thayers who belongs to my friend. If I played the thayers with more resistance on my lips they started to work and then they in fact needed less air but I sounded like a tuba and that's not my cup of tea. I guess it needs more time to learn than just a couple of minutes. I guess that more teutonic character is probably what I need to embrace if I want to learn to play that valve. I guess in time I could learn also to color the sound more. I think my problem coming from a comfortable world of old rotors is the opposite from those who come from a not comfortable world of old valves that are stuffy. From where I come, the old ways, I need to increase resistance in my lips to be able to play the thayer and they who come from the opposite place need to instead decrease the resistence in the lips to play the old rotors. It's as I see it two different ways of getting the resistence we all need to be able to make a sound. It might be possible to be comfortable in both techniques. Hagmanns is something in between so that's where we can meet. This is my theory. It's not that easy to change after many years of playing old rotors. If I ever consider another bass I might choose a double thayer just to explore if I can learn to play that valve with a sound I like. I know some probably like to think of the bass sound they want as "a big teutonic sound" or "a modern bass sound" or "a modern symphonic classical bass sound" as opposite to how I like to describe the sound I want; "a sound that projects like hell" or " a commercial sound" or "more lyric bass sound". I like many different sounds. Any sound that fits the context. Some very skilled players could probably cover any sound just imagening that sound on any valve-type they choose, but my belief is they probably are more comfortable on one of the valve-types, and that depends on where they come from. I think it's time for me to visit the few shops we have here and spend some time on a thayer-bass.

/Tom

[although]

I feel like other instruments don't have this fascination with finding the perfect valve... I don't haunt the tuba/trumpet/euphonium forums, so maybe I'm just not seeing it. Still, I sometimes think that we get way too wrapped up in the grail quest. Best valve is no valve.

[Posaunus]

In another thread, Sesquitone (Benny) makes the case that the F-attachment tubing I.D. (and valve ports) should be the same as the slide bore.

Question for Sesquitone:
Benny:
What is the typical Reynolds number (probably rather low) through the slide / valve / attachment tubing?
How does that affect things?

[brassmedic]

I feel like other instruments don't have this fascination with finding the perfect valve... I don't haunt the tuba/trumpet/euphonium forums, so maybe I'm just not seeing it. Still, I sometimes think that we get way too wrapped up in the grail quest. Best valve is no valve.

But that says it all right there: "Best valve is no valve". The holy grail is a valve that plays like it's not a valve. The reason the other brass instruments aren't looking for that is they are accustomed to playing every note through the valves. That's what they do. A valved trumpet does not sound like a natural trumpet, and a valved french horn does not sound like a natural horn. To them, that is a feature, not a flaw. And tubas have always had valves. They like the sound that they get. The trombone is unique in that it is essentially the same design as it was in the 16th century. That's the sound we want to hear, and a valve trombone does not have that sound. So trombone players look for a valve that will preserve that tone quality yet still give us added range and facility.

Zig Kanstul built a french horn with CR valves, hoping to offer this "improvement" to horn players. A horn player who tried it didn't like it at all. He was used to using the resistance of the traditional rotary valves to help connect the notes in a phrase. He liked the resistance. Horn players have no interest in more open valves. I suspect trumpet and tuba players wouldn't either.

[hornbuilder]

I agree with Brad.

I had a great discussion with Ed Thayer at one point. He was wanting to make a French horn with axial valves. He intended for the player to have the right hand outside the bell to correct into action by manipulating a tuning slide. I suggested that the valve resistance, or lack of with e axial design, would not be a positive for the player. But the real kicker would be not having the hand in the bell to adjust intonation. So sorry horn players. You didn't get axial valves because of me!!

[Sesquitone]

Question for Sesquitone:
Benny:
What is the typical Reynolds number (probably rather low) through the slide / valve / attachment tubing?
How does that affect things?

For steady flow of air through pipes, brass instruments are way down at the bottom/left-hand corner of the Moody diagram: laminar flow, small relative roughness. Therefore, the friction factor is going to be quite low. Very little "resistance" (end-to-end pressure drop), even with a valve or two along the way. Unless you have a valve half-cocked, for example, which changes things to "orifice flow". Then you can sometimes "feel" (and hear) some resistance. Especially if the valve is not well vented (thereby blocking the flow when half-cocked), in which case you get a lot of resistance, pressure build-up, and a "pop" when the valve is re-seated and the pressure relieved. An "ideal" valve should be so well vented (allowing laminar flow around the outsides of the active sound-path ducts during transition) that there is no hint of orifice flow (and therefore not the slightest sign of popping) when switching between the two active orientations.



.

[BGuttman]

Remember that the density of air is very small, the viscosity of air is near zero, and the exhalation flow rate of air is very small. I think if you calculate the Reynolds number for breath air flow through a tube approximately 13 mm in diameter you will find it to be 100 or less. This is below the left hand axis of your chart. In the scale of most engineering calculations of air in ducts or liquid in pipes our brass instrument flows are below any normal consideration.

[Sesquitone]

Remember that the density of air is very small, the viscosity of air is near zero, and the exhalation flow rate of air is very small. I think if you calculate the Reynolds number for breath air flow through a tube approximately 13 mm in diameter you will find it to be 100 or less. This is below the left hand axis of your chart. In the scale of most engineering calculations of air in ducts or liquid in pipes our brass instrument flows are below any normal consideration.

Yes, that's entirely correct. I should have shown an arrow pointing off the logarithmic scale across the left-hand border of the Moody diagram. Reynolds number in a pipe of circular cross section is defined as: fluid velocity (V) times pipe diameter (D), divided by the kinematic viscosity (nu) of the fluid, which, for air, is quite small at 1.5 x 10^-5 square metres per second. Plug in some numbers for a brass instrument, and, even with that small value of nu in the denominator, Re is well into the "laminar" region. Relative roughness is also very small for the type of surfaces found inside brass instruments. All of which means that, unless there is some kind of other constriction within the sound-path, the resistance to air-flow is almost negligible. However, acoustic impedance (matching sound waves from one end of the instrument to the other) is entirely unrelated to flow resistance or the volumetric rate of air-flow. Experiments have been done where there is a "membrane" across the bottom of the cup of the mouthpiece blocking air flow through the instrument (with a hole in the side of the mouthpiece to allow the air to escape)—but allowing sound-waves to propagate (and reflect back-and-forth), as usual. As I recall, the impedance spectra over a wide range of frequencies were essentially the same as with a normal mouthpiece (of the same shape). Perhaps someone can find a link to that study.

[brassmedic]

When people talk about matching the valve tubing to the inner slide bore, I don't think they consider what happens when you use the outer positions on the slide. On a .547 bore instrument, the inner diameter of the outer slide is around .585. If you play a note in 6th position, you are introducing a section of tubing that is much bigger in diameter than the valve tubing (normally .562). If you have an instrument with .547 valve tubing, a note played in first with the valve is going to be a lot stuffier than a note played in sixth without the valve. I think that's why makers have gravitated toward the .562 bore valve section - it blows more like the open horn.

[hornbuilder]

Thank you Brad.
My sentiments exactly, and experience in actual play testing many different prototypes with varying bore combinations. There is a very valid reason why there is a "standard"!!

[Digidog]

From all I know of flow theory, I call most of the statistical compilations for B.S.

Again: There are no theoretical calculations you can make to ascertain and guarantee certain desired traits of flow and resonance; you can calculate what is meaningful and purposeful to try and test, but no certain way of predetermining an outcome solely from a theoretical basis.

What most calculations miss are first turbulence - and the positive effect it can have on flow and resonance - and, second, changes in viscosity of the medium of the flow. A horn that plays really well in 20C or 68F, can be a disaster in 35C or 95F [EDIT] I once had a horn that changed like this, but not so drastically. [/EDIT] due to the changed viscosity of the air - which can depend on anything from the temperature itself or changes in humidity, or changes in particle contamination due to changed conditions, or simply the slight material expansion of the horn from increased temperatures.

As I said before, it could well make for a drastic increase in flow and resonance in a horn from making the tubing insides of - f.ex. - the bell roguh with microscopic knobs to create turbulence along the tube walls that aids an increased passage of air (and increase the speed from any given energy of the passing air) and makes resonance better in combinatin with a slight but dispersed increase in weight and its (regular or irregular, depending on) distribution.

From my own experience, I have seen flow increase from seemingly horribly mismatched pipes, where in one case turbulence from a sudden expansion in diameter actually increased the draining of an earlier placed long bend to the sewer pump in the plumbing of my summer house.

[jonathanharker]

Campbell, Murray; Gilbert, Joël; Myers, Arnold (2021). The Science of Brass Instruments. Cham: ASA Press. ISBN 978-3-030-55684-6
I've found this book to be very interesting for these sorts of discussions. In particular, section 4 goes into the acoustics, resonances, flow characteristics and sound radiation (bell flare, the "Horn function"); section 6 looks at non-linear propagation, acoustic pressure waves, Burgers Equations, and what happens and why things change when we play fortissimo (sawtooth waves!). Well worth a read if this sort of thing appeals.

[jonathanharker]

The CL2000 is a great valve [ ... ] I concur with Harrison, though, that there are some issues.
First: is it still in production, so spare parts or complete valves can be found? Or do one have to have a tech build parts from scratch if something like the rotor or a pin has to be switched? I have tried to purchase a complete valve for my Yamaha 421 through both the European and the Swedish Conn agencies (the 421's valve is worn and in need of replacing), but without any response at all from Conn. I don't see new horns from Conn equipped with the valve either, so it makes me wonder whether the valve is out of production or not.
[ ... ]
Over all, I think that the principles and the functions of the CL2000 are great. Had I been able to buy a valve from Conn for my 421, it had been my absolutely preferred choice, but now I'm planning to refit the horn with a Meinlschmidt valve. Then I have to see how the valves on my Conn 62 age, but this far everything has been fine and well, and if the build quality hasn't deteriorated catastrophically and if the valve still is in production, I'd wholeheartedly recommend it; both for a bass or a tenor horn.

The CL2000 valve patent expired in 2018, so (in theory at least) anyone ought to be able to build one.

From the above discussion about airflow and tiny Reynolds number, might that be why the unused "appendix" in the Y-shaped rotor inlet port might not matter as much as we think it should?

[Sesquitone]

The CL2000 valve patent expired in 2018, so (in theory at least) anyone ought to be able to build one.

From the above discussion about airflow and tiny Reynolds number, might that be why the unused "appendix" in the Y-shaped rotor inlet port might not matter as much as we think it should?

I'm always a bit leery about inadvertent "chambers" along the sound-path. René Hagmann tells the story of a Bach 42B with one of the earliest of his valves on it. One of the attachment notes was an unplayable wolf tone. After a lot of investigation (for leaks and so on), when he inspected the inside of the slide receiver, he found a large gap between the end of the slide and the beginning of the inlet knuckle of the valve, thereby causing a small oversized-bore "chamber". When he filled this with a small sleeve, creating a constant-diameter gap-free pathway throughout the receiver, the problem disappeared completely. Apparently, the "chamber" was acting as a little Helmholtz resonator, with its own (high) natural frequency. This may have been enough to interfere with the overtones of the problem note thereby causing the wolf tone. Mr Hagmann has routinely filled such gaps with constant-diameter sleeves ever since. This inadvertent gap seems to continue to be a problem with Bach instruments. Avoiding it is the main reason for the (thumb-screw-tightened) non-tapered butt-joint on Rath trombones. This is not a "tuning slide"!

As is well known, there is a whole "subculture" surrounding "The Gap" between the end of a trumpet mouthpiece shank and the beginning of the lead-pipe, with "camps" on many sides regarding how long this should be (if at all).

However, in the case of the CL valve, similar problems do not seem to have been reported.


.

[conn88Hagmann]

So I’ve gone back to my Hagmann Elkhart, with 547 bore plug. using it along side a Greenhoe Conn from about 2006 with 562.

The Hagmann feels the same in plug and open. The Greenhoe still has that “thing” they do. But Less so than on a standard valve . . .

[hornbuilder]

That is not a viable comparison. Different horns, different valve type.

I've done the experiment where I made 2 valve sections, using the same valve type. One was .547" bore with . 547" tubing. The other was .562" bore with .562" tubing. Same bell, tuning slide and handslide. I know what I think works better!!

Hagman valves do not play the same open vs activated. In my experience the valve side feels more "open" than the straight horn, and loses focus and core.

I'm curious about your comment of "that "thing" they do". What thing? Be specific, or your comment is useless.

[hornbuilder]

BTW. Hagmann do not use decimal/inch tubing size. They use metric mm tubing. Tenor valve section tubing is 14mm, which is .551". Bass is 15mm, which is .590".

[LeTromboniste]

BTW. Hagmann do not use decimal/inch tubing size. They use metric mm tubing. Tenor valve section tubing is 14mm, which is .551". Bass is 15mm, which is .590".

Interestingly, their default conversion kit for a Bach 42 (or at least it was when I got mine) has a 13.8mm (i.e. .543") bore Bb duct inside the valve (the F ducts match the F wrap with a 14.0mm bore)

You can also get it with 14.2mm (.559") ducts, ports and wrap, but that's not what they recommended for my 42.

[LetItSlide]

Remember that the density of air is very small, the viscosity of air is near zero, and the exhalation flow rate of air is very small. I think if you calculate the Reynolds number for breath air flow through a tube approximately 13 mm in diameter you will find it to be 100 or less. This is below the left hand axis of your chart. In the scale of most engineering calculations of air in ducts or liquid in pipes our brass instrument flows are below any normal consideration.

Thought-provoking post, there.

For us brass players, our horns are amplifiers for our vibrating lips. Of course, a horn is more than just an amplifier. It has mechanisms for controlling pitch, too. Anyway, we direct our airstreams in specific ways to get the sounds we want, but we aren't blasting air through our horns like water through firehoses. It's more about getting the amplifier to vibrate in the right way.

Many different valve designs work well. We learn the feel of the ones we happen to have in our horns, along with everything else about each horn's geometry & materials, and figure out how to get our best sound with each setup.