TubeNet

Does anyone have any information on what is reported to be an Eb/Bb tuba?
To me this looks like a compensating model, and not a tuba that switches keys via the extra valve.

A picture of the tubing in the back would help. I don't specifically know about the Salvationist horns, but I have seen a few 3+1 instruments that were not compensators. But if the horn has extra tubing between the valves in the back, it's almost certainly a compensating instrument.

Small non-compensated Eb tuba. B&H/Besson made a very few 3+1 non-compers in the same size, but the stays definitely tell this instrument not being re-badged, but being made at the SA-factory.

Klaus

Thanks, Klaus!

This horn does not appear to be a compensator. The piston casings don't appear to be long enough to house a piston with one additional circuit. A rear image of the horn would make it clearer.

Besides... what is a Eb/Bb tuba? Does that mean that someone thinks it will play in Bb if the 4th piston is strapped down?

TubaTinker wrote: Besides... what is a Eb/Bb tuba? Does that mean that someone thinks it will play in Bb if the 4th piston is strapped down?

Yes, that's exactly what the seller is claiming.

tubahed wrote:

TubaTinker wrote: Besides... what is a Eb/Bb tuba? Does that mean that someone thinks it will play in Bb if the 4th piston is strapped down?

Yes, that's exactly what the seller is claiming.

And it will. Probably very poorly.

Uncle Buck wrote:

tubahed wrote:

TubaTinker wrote: Besides... what is a Eb/Bb tuba? Does that mean that someone thinks it will play in Bb if the 4th piston is strapped down?

Yes, that's exactly what the seller is claiming.

And it will. Probably very poorly.

Very poorly indeed. Simply mashing down the 4th valve will deliver a Bb instead of an Eb. But.... it won't automatically extend the lengths of the tuning slides by 25%!

Eb tuba
1st valve = 20"
2nd valve = 9 1/2"
3rd valve = 29 1/2"
4th valve = 52"

BBb tuba
1st valve = 26.66"
2nd valve = 12.66"
3rd valve = 39.32"
4th valve = 69.32"

TubaTinker wrote:

Uncle Buck wrote:
And it will. Probably very poorly.

Very poorly indeed. Simply mashing down the 4th valve will deliver a Bb instead of an Eb. But.... it won't automatically extend the lengths of the tuning slides by 25%!

Isn't that exactly the point of the 'british' compensating system - that it DOES add the 25% to each valve?
As an engineer, this is how the theory of a compensating system should work. Add the 25% and voila, you have a BBb tuba simply by pressing a valve. May as well call it a 'double tuba - Eb/BBb' where it plays both keys with just the press of a valve.
As a tuba player, I know this doesn't exactly work. The compensating EEb tuba goes from good Eb to stuffy BBb (and that's with the good ones). There's really no way to add the tubing through the valves that doesn't constrict airflow with the 4th valve activated. It also doesn't adjust the main tuning slide to compensate for any differences in overall tuning that may result from playing in either cold or hot venues.

Just to be clear - I also don't know if the tuba at the top post has a compensating system.

I don't think that this is a sensible way of looking at tubas, after all, the Eb tuba doesn't become an E tuba by pressing down the second valve, and doesn't become a Bb tuba by pressing the 4th.
I am a Salvation Army tuba player, and in the past we (even I think wrongly) thought that by making our own instruments and putting a Salvation Army crest on them, they somehow became consecrated, to be used only in religious playing. The Army did make a compensated tuba called the "Super Triumphonic" similar to the Boosey and Hawkes Imperial model.
In the early 1960s it became economically unviable for the Army to make its own instruments, and many of our better bands were buying Boosey or Besson instruments anyway, and especially as the conversions for high to low pitch (or was it the other way round) were never entirely satisfactory.
The biggest collection of Salvationist instruments I have seen recently was in a Cornelia Parker installation, and they were all flattened

http://www.google.co.uk/url?sa=i&source ... 9721084439

(Sigh!) Without the compensation plumbing, this tuba will play no differently from any other conventional 4-valve Eb tuba, irrespective of configuration or valve type. The 4th valve on this tuba is only for Bb to be in tune, instead of 1+3 being sharp.

Without the compensation plumbing, 4+2 B natural will still be sharp, as will all other combinations of valves, unless pulled to "split the difference" between a single valve being only slightly flat and the combinations only being slightly sharp.

And it is not 25%. Do the math: it is the difference, for example of trying to get the combination of 4+2 to be in tune, between 2^(5/12) + 2^(1/12) of the open bugle length, which is all the tubing that is available without slide pulling on a conventional non-comp instrument, which this one is, and the added length of the comp tubes that bring it all the way to the necessary length of 2^(6/12) of the open bugle length [twelve semitones to the octave, each semitone being exponentially related by the function 2^(n/12), where "n" is the number of semitones down from open].

Go to David Werden's website for a proper explanation of how and why the "Blaikley-Boosey Automatic Compensating System of 1874" works, and works well, and is still the standard.

http://www.dwerden.com/eu-articles-comp.cfm" target="_blank" target="_blank" target="_blank" target="_blank" target="_blank" target="_blank

BTW - the patent covers both the 3-valve and the 4-valve systems. The 3-valve comp Besson New Standard BBb tuba I used to own had the most perfect intonation of any tuba I have ever played. The only reasons I sold it to a friend were because he needed a tuba, and I needed the near-pedal range which is the only thing the 3-valve comp system doesn't do well. If I ever need it, I know where to borrow it.

I actually thought that the purpose of the 4th valve was to enable the playing of a chromatic scale form low B natural to the fundamental Eb, and that the resolution of the tuning issues of the 1st and 3rd valves was a happy accident.

peter birch wrote:I actually thought that the purpose of the 4th valve was to enable the playing of a chromatic scale form low B natural to the fundamental Eb, and that the resolution of the tuning issues of the 1st and 3rd valves was a happy accident.

4th Valve alone doesn't do this for a standard (non-compensating) tuba. With just a standard 4th valve, the chromatic E (1/2 step above Fundamental Eb) is not possible without LOTS of added slide pull on an Eb tuba. Most 4 valve tubas don't have enough slide pull to reach this note. Tuning for 3rd valve and 4th valve is a matter of personal preference. Most of us prefer to tune 4th valve to replace 1+3. Some people tune 3rd valve so that 1+3 is in tune. I'm not sure what pitch they tune 4th valve to cover in that scenario.
On most tuba designs, the solution for reaching the note 1/2 step above fundamental is the added 5th Valve. Alternate fingerings also get used for that last 1/2 octave to avoid some of the slide pulls necessary to tune the notes.
The compensating system eliminates the need for both the alternate fingerings and the 5th valve in that range by effectively building in the slide pulls while the 4th valve is used. That was part of the design intent for Blaikley when he started designing the compensating piston system in the late 1800s. Tuba designs with more than 3 valves had been around for years and he was looking for a better way to play the pedal tones on pitch.

iiipopes wrote:(Sigh!)... And it is not 25%. Do the math: it is the difference, for example of trying to get the combination of 4+2 to be in tune, between 2^(5/12) + 2^(1/12) of the open bugle length, which is all the tubing that is available without slide pulling on a conventional non-comp instrument, which this one is, and the added length of the comp tubes that bring it all the way to the necessary length of 2^(6/12) of the open bugle length [twelve semitones to the octave, each semitone being exponentially related by the function 2^(n/12), where "n" is the number of semitones down from open].....

Never mind the 'big sigh'! YOU do the math! I'm talking about the difference between the fundamental Eb and BBb tuba.... it's roughly 13.5 feet as opposed to 18 feet. I think that equates to 25% off of the BBb open bugle.

Mashing that 4th button down has absolutely NOTHING to do with a compensating system. Even with a compensating tuba... that 4th valve is still a 1-3 combination. Get as technical as you want but it's still just a 4th valve.

Like Peter Birch mentioned... the question posed here is really not a sensible way to look at tubas (or any other valved instrument for that matter).

peter birch wrote: I am a Salvation Army tuba player, and in the past we (even I think wrongly) thought that by making our own instruments and putting a Salvation Army crest on them, they somehow became consecrated, to be used only in religious playing. The Army did make a compensated tuba called the "Super Triumphonic" similar to the Boosey and Hawkes Imperial model.
In the early 1960s it became economically unviable for the Army to make its own instruments, and many of our better bands were buying Boosey or Besson instruments anyway, and especially as the conversions for high to low pitch (or was it the other way round) were never entirely satisfactory.

http://www.google.co.uk/url?sa=i&source ... 9721084439

That is really interesting. I've always thought they were made by Besson for no particular reason other than they looked like Besson / Boosey & Hawkes. Do you have any production numbers and years that the SA built their own horns? Were the instrument designers / makers themselves part of the SA?

TubaTinker wrote:

iiipopes wrote:(Sigh!)... And it is not 25%. Do the math: it is the difference, for example of trying to get the combination of 4+2 to be in tune, between 2^(5/12) + 2^(1/12) of the open bugle length, which is all the tubing that is available without slide pulling on a conventional non-comp instrument, which this one is, and the added length of the comp tubes that bring it all the way to the necessary length of 2^(6/12) of the open bugle length [twelve semitones to the octave, each semitone being exponentially related by the function 2^(n/12), where "n" is the number of semitones down from open].....

Never mind the 'big sigh'! YOU do the math! I'm talking about the difference between the fundamental Eb and BBb tuba.... it's roughly 13.5 feet as opposed to 18 feet. I think that equates to 25% off of the BBb open bugle.

Mashing that 4th button down has absolutely NOTHING to do with a compensating system. Even with a compensating tuba... that 4th valve is still a 1-3 combination. Get as technical as you want but it's still just a 4th valve.

Like Peter Birch mentioned... the question posed here is really not a sensible way to look at tubas (or any other valved instrument for that matter).

Dan,

That was my whole point - no, the 4th valve by itself and its own circuit not fed back through the block has nothing to do with the compensating system. But a 4th valve does add the extra tubing to get notes played by a 4th valve in tune, which are not in tune when played 1+3 without pulling either the 1st or 3rd slide to get them there.

I'm agreeing with you. We are just saying it different ways.

Sorry I ruffled your feathers. I didn't mean to. It's a complex issue. Here's the math:

Let's see: if an Eb tuba is about 13 1/2 feet long, or 162 inches long, then theoretically:

2nd valve circuit would be [162 * 2^1/12] - 162, or about 9.63 inches.
1st valve circuit would be [162 * 2^2/12] - 162, or about 19.84 inches, which is a little longer than twice the length of the 2nd valve circuit.
3rd valve circuit would be [162 * 2^3/12] - 162, or about 30.65 inches, which is longer than the 1st valve circuit and 2nd valve circuit together, which is only about 29.47 inches, so a pull of about 1/2 or so, totaling the difference of a hair more than an inch, is necessary to get 1 + 2 in tune if not using the 3rd valve alone, but keeping it pulled so 2+3 is in tune, which is what most players do, and how many older tubas were constructed. As a result of 3 being long, then 1+3 needed less lipping or pulling than on instruments where the 3rd circuit is of "dead" length, so you use 3rd alone, instead of 1+2. This is/was the case with 3-valve comp system instruments, including tubas, euphs, and baritones, which add the required tubing when 3rd is pressed in combination with either 2, 1 or both, since there is no 4th, so that 2+3 and 1+3 have the additional tubing through the comp circuit to be in tune.
4th valve circuit would be [162 * 2^5/12] - 162, or about 54.24 inches. Yes, 162 + 54.24 is 216.24 inches, which is about what the open bugle of a BBb tuba is.

This is where our misunderstanding may have occurred: of course, 54.24 is about 26% of 216.24. You were expressing it in relation to what an open BBb bugle would be, and I was expressing the individual valve slide lengths as combined in relation to the Eb open bugle.

I was also trying to say that the length of the 4th valve circuit, by itself, is the same, whether or not on a non-comp or on a comp tuba, because on a 4-valve comp, the comp loops only come into the circuit, of course, when one or more of the other valves are pressed in addition to the 4th valve.

Here's where my real point was: 1 + 3, without extra pulling, is about 162 + 19.84 + 30.65, which is only 212.49 inches of tubing engaged, which is significantly shorter than the full 216.24 inches necessary to get the note in tune, requiring not quite a 2-inch pull, on either 1 or 3, or some combination thereof, to get the full almost 4 additional inches necessary to get the note down to pitch and not be sharp without pulling or lipping.

Finally, to restate what I thought I was trying to explain, however inartfully, was that the lower notes below 4th valve need exponentially even much more tubing than that:

My example was that simply pressing 2+4 would be 162 + 9.63 + 54.24 inches, or about 225.87 inches of tubing engaged on a non-comp horn, but the pitch needs [162 * 2^6/12] or about 229.1 inches of tubing to get all the way down to pitch. So either 2 or 4 or some combination of each also needs to be pulled a significant amount on a non-compensating horn to bring the note down to pitch without lipping, and which, again, as we all know, is the purpose of the comp loops: to add this extra tubing by running the circuit back through the valve block.

Epilogue: all these are, of course, theoretical values, modified by the taper of the branches and everything else that goes into just how much tubing and in what progression of diameter and placement is required to get to the pitch. But hopefully this demonstrates my point.

Curmudgeon wrote:Every Salvationist I've seen was built like a tank. Very sturdy, which is not to say "she has a great personality..."

You are of course merely referring to the tubas

NCSUSousa wrote:Isn't that exactly the point of the 'british' compensating system - that it DOES add the 25% to each valve?

As an engineer, this is how the theory of a compensating system should work. Add the 25% and voila, you have a BBb tuba simply by pressing a valve. May as well call it a 'double tuba - Eb/BBb' where it plays both keys with just the press of a valve.

No and no.

1) The "British" (Blakely and/or Boosey) system was designed to compensate for the sharpness caused by using valves in combination ... a simple concept that is often very difficult to communicate.

Basically the length of each valve circuit adds enough length to the open bugle to lower the pitch by a musical half, whole or 1.5 step for a 3 valve setup. When one valve is already depressed, the effective length of the horn is longer than the open bugle. So adding the length of another valve (whose length is predicated on the open length) does not add enough tubing to lower pitch the intended amount.
Here is a good description of the needs and the solution.


2) Double horns (instrument designed to play in two different keys) do exist but the solution to this problem is mechanically much more complex than simply adding a valve or even adding the compensating tubing discussed above. Double french horns are quite common, usually F/Bb. Double tubas are far less common but do exist. Click the photo for a description of one design.

bigtubby wrote:

NCSUSousa wrote:Isn't that exactly the point of the 'british' compensating system - that it DOES add the 25% to each valve?

As an engineer, this is how the theory of a compensating system should work. Add the 25% and voila, you have a BBb tuba simply by pressing a valve. May as well call it a 'double tuba - Eb/BBb' where it plays both keys with just the press of a valve.

No and no.

1) The "British" (Blakely and/or Boosey) system was designed to compensate for the sharpness caused by using valves in combination ... a simple concept that is often very difficult to communicate.

Basically the length of each valve circuit adds enough length to the open bugle to lower the pitch by a musical half, whole or 1.5 step for a 3 valve setup. When one valve is already depressed, the effective length of the horn is longer than the open bugle. So adding the length of another valve (whose length is predicated on the open length) does not add enough tubing to lower pitch the intended amount.
Here is a good description of the needs and the solution.


2) Double horns (instrument designed to play in two different keys) do exist but the solution to this problem is mechanically much more complex than simply adding a valve or even adding the compensating tubing discussed above. Double french horns are quite common, usually F/Bb. Double tubas are far less common but do exist. Click the photo for a description of one design.

Maybe you should read the article you've linked. They describe on page 7 (page #52 on the pdf page) that the compensating system as designed by Arban for the trumpet (and improved by Blaikley) is essentially a 'double' trumpet. It would not be wrong to call it a double trumpet if that's what it actually achieves, even if there are other methods for getting there (see the double tuba link that you've provided as an alternate method).
Of course, Blaikley's system continued to be used because it was sold better to the brass bands of the time. It may actually be better, but history shows that salesmanship matters more than actual product quality.

tofu wrote:

peter birch wrote: I am a Salvation Army tuba player, and in the past we (even I think wrongly) thought that by making our own instruments and putting a Salvation Army crest on them, they somehow became consecrated, to be used only in religious playing. The Army did make a compensated tuba called the "Super Triumphonic" similar to the Boosey and Hawkes Imperial model.
In the early 1960s it became economically unviable for the Army to make its own instruments, and many of our better bands were buying Boosey or Besson instruments anyway, and especially as the conversions for high to low pitch (or was it the other way round) were never entirely satisfactory.

http://www.google.co.uk/url?sa=i&source ... 9721084439

That is really interesting. I've always thought they were made by Besson for no particular reason other than they looked like Besson / Boosey & Hawkes. Do you have any production numbers and years that the SA built their own horns? Were the instrument designers / makers themselves part of the SA?

to be honest, I don't know, the Salvation Army Heritage centre might know, but the Army did have a factory making brass instruments that ran from the 1880's up to its closure in 1972. In those early days, it could well have been part of the social elevator program the Army ran in the UK.
the instruments were robust, to stand up to outdoor use by musicians who were none too careful with them, and heavily silver plated, which would give them some residual value, even if they are not really playable these days.