Valve Height or Throw Distance

[dsurkin]

Doug: thanks for the detailed answers and the photo. If I understand what I'm looking at, the piston ports are oval for the compensating loop but round for the non-compensating loop?

I've never played a top-sprung valve set. Does it use the same springs? How do you replace the springs when they start losing resilience?

[notaverygoodname]

Apologies in advance for my not being a legit musician, but I made a video trying to see if I can detect any sort of odd behavior with the short-action valve. I didn't notice anything, but it's entirely possible that I'm just not good enough to tell.

facebook video link

My takeaways:

- 99% of my horns are in terrible condition and have worn out, noisy valves.
- The 20I dominates the Trombonium in terms of valve speed, despite a .060" bore disadvantage.
- The 20I is a great playing instrument, but I think I'm happier on rotors at this point.

[daruby]

I've never played a top-sprung valve set. Does it use the same springs? How do you replace the springs when they start losing resilience?

Doesn't use the same springs. In fact the springs on this horn were obviously cut down from something else to shorten them as the spring has a flat coil at one end and is just cut off at the other. Doesn't seem to affect anything. Since the springs sit inside a sleeve at the top of the valve, they do not have as much room (in diameter) as bottom sprung valves. I will have to see what kin of springs would work best when it comes time to replace them. Probably a stiff baritone spring.

Doug

[Charlie Baker]

Thank you, John - and everyone who responded. Very informative. Sort of as I suspected - I could play faster passages, if I could play faster passages. It's the fingers, not the horn!

[davewerden]

At the risk of muddying the waters, let me add some observations and thoughts.

For the latter, I believe that in an all-else-being-equal scenario, any of the following would increase the speed at which a piston could operate (i.e. move enough to properly change the airflow):

- shorter action
- lighter piston assembly (including the stem and finger button)
- increasing ports for airflow through the piston (if they are now marginal)
- reducing friction via lubrication
--- further reducing friction via the viscosity of the lubrication
- absolutely clean surfaces of piston and inner cylinder
- stronger springs

Observations

First, I seldom encounter anyone whose own technique is being slowed by the valves, except when they are sticking or sluggish because of a problem. However, their comfort level might increase with changes to the valves.

Springs: I like a little heavier-than-normal spring. This gives me quicker upstroke and less bounce at the top. They require more strength, obviously, but once I'm used to that I benefit from faster speed AND slightly cleaner-sound technique (because of the lessened bounce). Adams uses a softer spring. When I had that yellow brushed loaner a year or so ago, it actually did slow me down because of the springs. Once secondary problem of this is my coordination was messed up. Because the valves didn't return as quickly, they were out of contact with my fingertips, and that affected my micro-reactions. All this was only noticed, or rather became a problem, only when I was playing really fast. If you have any inherent weakness in your right hand, you might not want heavy springs; injury could result.

Lightness/friction seemed to both have been improved by a B&H Imperial that Glenn Call had modified. He had the valves shortened by eliminating the excess length at the bottom - it was more than needed to keep the spring in place. And he had a serious chamfer made at the top and bottom. The piston was lighter and had less contact area. That was the fastest-feeling set of B&H/Besson valves I had ever encountered at the time (maybe late 1970's or early 1980's).

After my recent cleaning, the valves are still not what they usually are. Even after soap & water cleaning, I strongly suspect there is some residue on the pistons. I may try an ultrasonic cleaning of pistons next. If that doesn't work I'll take a stronger cleaner or polish to the stainless steel.

Lubrication. Interesting topic! Logically, one would think the thinnest possible oil would be best. However, it is not a perfect world. Today's valves are really good, but there are probably microscopic irregularities in the surface, probably impossible to avoid with all the passageways in the piston and the attached tubing for the casings. Perhaps the thinnest oil would not provide the extra "body" to help smooth all this out. Then there are probably chemical concerns. I think one's own chemistry can change the behavior of the oil one way or another.

As I said, for some people's playing, valves are not the limiting factor. For others, optimizing the valve behavior might give them an edge.