Dates of "Berliner pumpen" use?

windshieldbug · Post by **windshieldbug** » Thu Sep 21, 2006 1:21 am

Berliner valves were used on the first tubas (c.1833)
They were made at least up to c.1900

The only variation I'm aware of involves internal and external valve guides, and valve slides looping under the valve or coming out "normally".

windshieldbug · Post by **windshieldbug** » Thu Sep 21, 2006 7:49 pm

Berlin valves from National Music Museum

Early Valve Designs from Horn Articles Online

Chuck(G) · Post by **Chuck(G)** » Thu Sep 21, 2006 8:45 pm

Holton used a variation of the Berliner valve well into the 1930's. They turned the valve on its side, making a round piston with two "cups" carved out of it. All 4 tubes enter the casing on the same side, stacked one on top the other.

When the valve is in the "released" position, the airstream enters and exits the center tubes. When the valve is depressed, air again enters the center tube, exits to the tuning slide on the top tube and returns via the bottom tube and finally exits through the other middle tube.

All pistons are interchangeable. It doesn't work all that well, because there's a lot of spaghetti tubing to get the airstream from one valve to the next.

But it's interesting.

Yeah, I know, Dale--Freak--but it is a 6/4 Holton

Chuck(G) · Post by **Chuck(G)** » Thu Sep 21, 2006 10:28 pm

Scooby Tuba wrote:Call me PT Barnum, 'cause I love the freaks!

Kind of a short action kind thing on that Holton or were they a full stroke valve with character?

Cool looking valve caps.

Although not strictly a Berliner Pumpen valve horn, I'd love to see a full horn shot of that beauty

The valve ports are ovalized--i.e. short-stroke.

This horn now belongs to another TubeNetter--I replaced the bell front with a Miraphone 190 bell. It's not a bad player, but too big for my tastes.

Chuck(G) · Post by **Chuck(G)** » Fri Sep 22, 2006 8:57 pm

Scooby Tuba wrote:Although not strictly a Berliner Pumpen valve horn, I'd love to see a full horn shot of that beauty

From a topological sense, I'm not so sure that they aren't Berliner valves. Consider that a BP valve functions as a rotary valve with two rotors--one offset by 90 degrees from the other--and instead of turning the rotor 90 degrees, axial motion is used to switch between a rotor offset 90 degrees from the another.

Okay, now take a rotary valve and turn it on its side, so the shaft lies in a horizontal plane, then cut vertically right through the valve, so each piece has a D-shaped half shaft. Stack the halves on top of one another, join them and you've got the Holton valve.

Maybe it's a stretch, but the standard rotary valve, the BP and Holton are all basically the same in principle. Only the means to accomplish the change in air direction differs.

...or so it seems to my warped mind.

windshieldbug · Post by **windshieldbug** » Fri Sep 22, 2006 9:25 pm

Chuck(G) wrote:From a topological sense, I'm not so sure that they aren't Berliner valves. Consider that a BP valve functions as a rotary valve with two rotors--one offset by 90 degrees from the other--and instead of turning the rotor 90 degrees, axial motion is used to switch between a rotor offset 90 degrees from the another.

Okay, now take a rotary valve and turn it on its side, so the shaft lies in a horizontal plane, then cut vertically right through the valve, so each piece has a D-shaped half shaft. Stack the halves on top of one another, join them and you've got the Holton valve.

Chuck(G) · Post by **Chuck(G)** » Sat Sep 23, 2006 12:28 pm

Scooby Tuba wrote:The 'bug put up a graphic that I also ran across. In looking at the Holton valve, it seems as though the upper and lower port are the same. So, in that there are four sets of tube going into the valve, is it true that in the up position 1&2 and/or 3&4 are in play and when the valve is depressed 2&3 and possibly only 4, but not 1 are in play?

Number the tubes on the side of the Holton casing top to bottom as 1 2 3 4.

The airstream enters at 2 and exits at 3. When the valve isn't depressed, the lower cavity on the piston connects 2 and 3, so the valve is straight-through. When it's depressed, 1 is connected to 2 and 3 to 4. The tuning slide is connected to 1 and 4. So then, the air path is in at 2, out at 1, back in at 4 and out at 3. Just like a rotary valve.

The problem with this, however, is that even in the "straight through" mode, the airstream must make a 180 degree reversal through the valve--and two reversals in the "depressed" mode. Couple that with the 180 degree turn that connects one valve with the next, and you have a very contorted air path.

The size of a BP is easy to explain if you consider that it's nothing more than a rotary valve that switches the port orientation 90 degrees by going up and down. The size of the valve must still match the size of a corresponding rotary. By ovalizing the airpath, you can reduce this size considerably, but it's still going to be a long distance between piston centers on a tuba.

On a related note, does anyone know when the last Vienna valve tuba was made? Sometime in the 80's, maybe? Or is it possible to special-order one today from one of the smaller manufacturers, like Alexander?