Odd Blaikley variant

[imperialbari]

Boosey held the Blaikley patent for 3 and for 3+1 compensators until the merger with Hawkes around 1931. Besson joined in around 1940. Until the mergers there were several attempts to come up with alternatives to the Blaikley system, which however won in the long run.

Recently found a 1927 Besson variant on an Eb tuba with 3 valves. Functionally it is very close to the true Blaikley model, but it tries to achieve one more goal seen on the old Briotis tubas with the valve loops on the rear side: part of the 3rd loop acts as a rest for the right hand.

Doing so leads to a design feature, which I consider plain silly due to potential extra leaks: the 3rd loop passes through the 3rd piston. As weren’t the high number of valve passages not already a main complaint against compensating systems.

The auction gives the year of 1944, but that cannot be true as Besson was repurposed for war at that time. They made fuel supply systems for fighter planes. And circumventing the patent would make no sense after the merger. The year rather is 1927:

http://cgi.ebay.de/ws/eBayISAPI.dll?Vie ... 0680885202

Klaus

[Rick Denney]

Recently found a 1927 Besson variant on an Eb tuba with 3 valves. Functionally it is very close to the true Blaikley model, but it tries to achieve one more goal seen on the old Briotis tubas with the valve loops on the rear side: part of the 3rd loop acts as a rest for the right hand.

I don't have access to them here, but I made some pictures of a 3-valve compensating Besson from the mid-20's that also seemed like a variant of the Blaikley system. Here's the description I posted when we sold it:

http://www.chisham.com/tips/bbs/nov2001 ... 74761.html

Unfortunately, the picture has gone missing from the place where I stored it, and I'm not sure why. I can't find it in online archives, so I'll have to look for it at home.

Rick "was it really 10 years ago?" Denney

[imperialbari]

The Enharmonic system is not compensating like the Blaikley and this present variant. The 3 valve BBb Enharmonic tuba rather may be compared to a true double horn. Seen in that light the technical term would be

double tuba in BBb & GG with two valves on each side and the 3rd valve acting as shift valve.

Charley Brighton tells that the enharmonic system is so heavy that whereas euphoniums and Eb tubas also came in 4 valve variants, then the BBb basses only came in the 3 valve variant.

The airpath of the BBb Enharmonic tuba is complex beyond verbal description. My Yahoo-based gallery has two such entries with at least one having good photos. The index is here:

http://launch.groups.yahoo.com/group/Yo ... %20format/

Klaus

[Highams]

Both the Compensating & Enharmonic sytems were available on every brass band instrument except the E flat soprano cornet. As mentioned above, only 3v versions of Enharmonic B flat bass tubas were listed.

There was also the Hawkes Dictor system, on Euphs only as far as I know;

http://s91.photobucket.com/albums/k309/ ... =itea6.jpg" target="_blank

http://s91.photobucket.com/albums/k309/ ... Ditea5.jpg" target="_blank

which looped valves 3 & 4 together.

There was also a Syncro(tonic?) system I'm trying to find out more about.

CB

[Rick Denney]

The Enharmonic system is not compensating like the Blaikley and this present variant.

I remember that rather than adding compensation loops when the control valve is pressed, it routed the non-control valves through completely different branches when the control valve was depressed. It does not really add additional complexity except when the instrument is played open, because then the path goes through the valves twice.

Your pictures are exactly like the one I was describing in the link I provided. When I had that instrument in my hands, I followed the routing throughout the instrument to figure it out. It was a stuffy instrument, but in a way that was not untypical of British instruments of that era, it seems to me. And when I played it its best days were long behind it. It had gotten a valve job but with valves that long it did not really restore full compression.

Rick "who sold it to a tuba player in a period-instrument brass band" Denney

[iiipopes]

It's interesting that this varient has the 3rd valve coming back through the third valve, so the air flow goes 1-2-3-2-1 instead of the "conventional" Blaikley loop-back-around 1-2-3-1-2-3. Yes, the enharmonic system had two sets of 1st and 2nd slides, one set longer than the other. When the 3rd valve was engaged, it routed everything through the 2nd set of slides with longer lengths, and that was the "compensation" on that horn. But with two sets of slides, it got really heavy, and was discontinued.

[imperialbari]

With all 3 down and DP indicating double passage(at both ends of a loop) & SP for single passage (for a through)

1(DP)-2(DP)-3(DP)-1(DP)-2(DP)-3(SP)

The normal Blaikley pattern for the 3 valve variant is:

1(DP)-2(DP)-3(SP)-1(DP)-2(DP)-3(SP)

The second passage of the 3rd piston in this Blaikley variant is not necessary for acoustic reasons. It is only motivated in architecture.

Klaus

[Rick Denney]

With all 3 down and DP indicating double passage(at both ends of a loop) & SP for single passage (for a through)

1(DP)-2(DP)-3(DP)-1(DP)-2(DP)-3(SP)

The normal Blaikley pattern for the 3 valve variant is:

1(DP)-2(DP)-3(SP)-1(DP)-2(DP)-3(SP)

The second passage of the 3rd piston in this Blaikley variant is not necessary for acoustic reasons. It is only motivated in architecture.

Klaus

With the old Besson, all valve configurations resulted in going through each valve twice. But it only went through one valve branch. With Blaikly, the switch valve send it through the valves again, through an additional branch. So, I might define T as a through-port, B as a branch (with a tuning slide), and CB as a compensating loop. All three valves on the old Besson was: Leadpipe>3B>2B>1B>1T>2T>3T>bugle. When 1 or 2 are depressed without 3 being depressed, 1 and 2 use different branches. 1 and 2 only use one branch or the other when they are depressed, depending on whether 3 is also depressed.

With a three-valve Blaikley compensator, all three valves down would lead to: Leadpipe>1B>2B>3B>1CB>2CB>3T>bugle. With the instruments open, the old Besson was Leadpipe>3T>2T>1T>1T>2T>3T>Bugle, and the Blaikley compensator is Leadpipe>1T>2T>3T>Bugle.

So, the Blaikley system is less tortuous when the instrument is played on the open bugle. When all valves are depressed, the old Besson might have the advantage.

But it's hard to compare--there were other differences between the old Bessons and a newer three-valve Blaikley compensator that also contribute to the older instrument being stuffy.

Rick "whose mid-60's Stratford with no compensation was stuffy, too" Denney

[Rick Denney]

A pair of simple tuba shoes renders all of those systems obsolete. http://cgi.ebay.com/Simple-Tuba-Shoes-/200589256325

bloke "engineers... "

Nope. They don't conform to my band's dress code.

On the other hand, maybe that's why our intonation sucks.

Rick "wondering if hemp can be dyed" Denney

[Highams]

What key are they in?

CB

[imperialbari]

What key are they in?

CB

A tiresome question!

Vert rarely seen from Charley.

Klaus