Are rotary valves better?

Piston Valves vs. Rotary Valves- What&#;s the Difference?

A Little Bit of History: Before the invention of slides and valves to change pitch chromatically, early brass instruments were fairly limited. Trumpets and horns were only able to produce notes within the harmonic series, in other words those produced naturally by a single length of tubing. Players could swap the &#;crook&#; of the instrument to change the length of tubing and play a different set of notes, but playing chromatically was not possible. Horn players could also change the pitch by placing a hand inside the bell, known as &#;hand-stopping&#;, though this also vastly changes the timbre of the instrument. When valves first began to be introduced in the 19th century, they changed the game for brass players by offering them a full scale of notes to play with, vastly increasing the expressive freedom of the instruments.

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The Technical Bit: Piston Valves and Rotary Valves both do essentially the same thing, but achieve it in a different way. When the valve is pressed, it reroutes the air through an additional length of tubing, lowering the pitch by a set amount. A spring then returns the valve to its original position.

Piston Valves: Piston Valves achieve this effect by moving a cylindrical stock inside a cylindrical casing. There is plenty of &#;travel&#; in these types of valves, making &#;half-valving&#;, a technique most often employed by jazz players, easier than with Rotaries. Piston valves also produce a cleaner and more definite movement between notes, making them ideal for quick passages where each note needs to be heard clearly.

Rotary Valves: Instead of moving up and down, the stock inside a Rotary Valve rotates through 90 degrees to redirect the air. Rotary valves produce a smooth transition between notes making them ideal for playing lyrical passages like those found in classical music. Rotary Valve instruments are said to produce a broader, mellower sound than their piston counterparts. These factors make them ideal for the French Horn, which is often used in legato passages in Symphonies. Although the most common instrument to use Rotary Valves is the French Horn, Trumpets, Flugelhorns, Euphoniums, Tubas and other brass instruments are also made in rotary valve variations. These instruments are rarely seen in the UK but have gained more popularity in Austria, Germany and Eastern Europe. Check out our range of brass instruments by clicking here!

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Post by PaulMaybery » Thu Apr 06, 12:13 pm

Sometimes we forget the nature and condition of the piston or rotary valve and its attendant mechanism. Old and worn usually translates into issues. Worn pistons leak and worn rotor mechanisms rattle. Choose your poison. On the positive side, worn pistons tend to move quickly, but if you care about the sound, the thicker oil needed for the hydraulic seal slows things down. Noisey rotor linkage may or may not respond to lubrication and greasing the joints. The rotor itself should not actually touch the casing wall and hence does not wear, this leaves the bearing/spindle to carry the weight and eventually wear. A tech with experience swedging those bearings can add life to the rotor. Other techiniqes involve rebuilding the valve.

For what it is worth, there should be readily available rebuild kits for rotary linkage: from just a simple replacement of the minibal or uniball end bearings to the whole paddle and pushrod assembly. Seems like there is this clandestine procedure involved to get those parts from a manufacturer and so few technicians seem to know very little if anything about where to obtain them.

In the automobile industry there are kits for rebuilding carbuerators, pistons, break assemblies and the list goes on.
Why not some generic parts for tuba rotary mechanisms that are a cut above having to use radio control hobby parts.

Perhaps out friends at Wessex might take the lead and offer such kits for their instruments, though I doubt at this stage any of their tubas actually need that attention. The time will come however. I happen to have 3 Wessex instruments with rotary valves and all of them work great: smooth, fast and quiet. I find them luxurious to play. But how long will that newness last? And when the time comes I would love to be able to simply have access to a rebuild kit and return the horn to that well fitted 'new like' valve assembly.

Wessex 5/4 CC "Wyvern"
Wessex 4/4 F "Berg"
Wessex Cimbasso F
Mack Euphonium
Mack Bass Trombone
Conn 5V Double Bell Euphonium (casually for sale to an interested party)

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