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I think that I asked the question badly, on the new euphonium thread, so here it goes again...

I know that the bore size defines the size of the valve stroke on a piston instrument, but I am curious (perhaps about the relative bore sizes) of the leading compensating euphoniums.

I have a Yamaha 321, and noticed a significant INCREASE of stroke length between that horn, and a YEP 642. Not having other brands available to evaluate, do all the major brands of compensating euphoniums have a similarly long stroke? I also have a specific interest in the differences (if any) between the YEP 641, and 642.

Can anybody help?

THANKS!

Z-Tuba Dude wrote:I have a Yamaha 321, and noticed a significant INCREASE of stroke length between that horn, and a YEP 642.

Remember that the valve stroke on a compensator isn't controlled by the nominal bore of the valve tubing, but by the compensating tubing, which is the same bore as the fourth valve, and usually bigger. This may explain why the 642 has a longer stroke than the 321.

I can measure my Besson, but since it's not made any more, it may not be relevant. I would expect it to be similar to a Sovereign. I just have to remember to do it.

Rick "forgetful on leaving the office" Denney

I have a 641 and have also played the 642. I can't tell any difference between these two horns with regards to valve tavel (or stroke).

BTW - the main bore size is the measurement of the inside diameter of the second valve slide. Sterling will sometimes list their bore size as being larger than the Willson or Yamaha pro horns. According to David Werden, this is a marketing ploy. Sterling measures their bore as 'outside' diameter of the second valve.

Something I noticed when I was comparing my 642 to the Willsons, is the all the time I thought the Willson had a shorter valve distance, but if my crude measurements were correct, it actually had a slightly longer stroke than the 642. However, the valve button goes further into the valve cap when it goes down, plus the fact that the hand brace is closer, I guess makes it seem shorter.

Rick F wrote:I have a 641 and have also played the 642. I can't tell any difference between these two horns with regards to valve tavel (or stroke).

BTW - the main bore size is the measurement of the inside diameter of the second valve slide. Sterling will sometimes list their bore size as being larger than the Willson or Yamaha pro horns. According to David Werden, this is a marketing ploy. Sterling measures their bore as 'outside' diameter of the second valve.

The official bore size is measure in the second-valve slide, but the bore size that controls how far the valve must move is controlled by the larger compensating bore. There's a minimum distance the valve has to move to keep the ports from leaking or overlapping, and it's the larger hole that determines that distance.

Rick "whose Besson has a noticeably larger bore in the ports for compensating branches" Denney

Okay. That makes sense Rick.

On the Yamaha 641, 642 and 842, the bore of the compensating side is advertised as being .661.

Yamaha Euphonium Specs
...the 641 is no longer listed

What is the 621 then?

Ryan_Beucke wrote:What is the 621 then?

Well, the YCB/YFB 621 is Yamaha's small 3/4 TUBA.

The YEP 321 is their 4 valve, non-compensating euphonium.

Ryan_Beucke wrote:What is the 621 then?

The YEP 621 is a 3+1 non-compensating euphonium with the same bore (but for the 4th valve) of a YEP-321. Not sold in the USA, however.

Beats me why.

***

[/quote] Seems someone could come out with a 3+1 that was close to the same price.

Jupiter has the new 570 euph. For ca. $1100, it's one heck of a horn.

Norm in Bellevue, looking forward to his first TubaChristmas tomorrow!