the elephant wrote:No nastiness at all! This is funny stuff. We were all just dancing around the answer, thinking how clever we were and falling on our collective faces. So we then just laid it out there for you. I certainly hope that you did not think that any of OUR feathers had been ruffled!
I really DID think I had ruffled feathers. I will develop a thicker skin (that will be on my list of evolutionary processes over the next 10 or 12 thousand years).
Bloke, thanks for the info about your band's solution. It would seem to be very logical. My fourth slide pulls about 5 inches, and I am STILL badly sharp (unless I just blow the hell out of the note; you know, FF even if the part is written pp). Now to find a GREAT repairman in South Florida ... the best ones are up north of here at least 600 miles.
Last edited by jmerring on Sun Oct 05, 2008 9:51 pm, edited 1 time in total.
It stands that the given combination of instrument and player comes out sharp on the two most common notes fingered 4 on a BBb tuba. bloke has come up with one potential reason for the problem, even if I wonder why Miraphone would fail on its old reputation of building maybe less than exiting instruments, but very reliable instruments.
A cross check may be done to see if this tuba has been intruded a hat, a toy, or another physical entity.
If the valves are set up correctly by the maker, the said C and F shall sound slightly sharper when fingered 1+3 versus fingered 4. If these notes also sound extremely sharp when fingered 1+3, then an obstruction of the main bore would be very likely.
It might be worth hosing out the main bugle and if there are no obstructions there, also the valve tubing. While I had a bathtub I covered the bottom with a large towel and placed the tuba there with the leadpipe pointing upwards. I took the handle off the shower hose and put the hose to the leadpipe, so that the bore was flushed with warm water. Make sure you have a firm grip on the hose. Also make sure all slides are pushed all the way in. If the water pressure is too high the slides may pop out when the valves are activated.
My new home has no bathtub, so there I put the towel on the bathroom floor and then carry out the same procedure.
Unless someone has been playing my horn, while I wasn't looking; there is no obstruction in it. I am it's first owner and it is my 'child.' I have tried reversing the 4th valve (left to right) and that helped a little bit. My knowledge of the inner workings of rotary valves is limited (at best), but I am going to ask my local repairman if the 4th is aligned correctly, because I have been noodling around with the back cap to increase valve speed (it slows to a crawl if the cap is too tight - which I am sure all of you know). Thank you again, friends. BTW, if there is a simple way for me to check valve alignment; could someone fill me in (pictures, please ... no big words ...OG stupid!).
On all rotary valve horns, including especially Miraphone, when you unscrew the bottom rotor cap (the one you have been adjusting) you should see two notches filed into the rotor casing to indicate alignment, and one notch on the rotor that should line up with each casing notch in closed and open positions respectively. If they don't line up, and it's something more than a straightforward replacement of bumpers will fix, then, and everybody sing along to the tune of the William Tell Overture:
To the tech, to the tech, to the tech, tech, tech!
Wow; thanks for the information, guys! I will look VERY closly at my caps and alignment marks (magnifying glass). I hope this helps. I probably screwed it up to start! Again; OG STUPID!!
Another thing to check are the ferrules on the main tuning slide. I have seen a number of horns that came over with European slides (where the pitch is A=443 or so). If the main tuning slide ferrules are about 3/4 of an inch long and not closer to 2 inches, then you most likely have Euro slide on it and have been successfully lipping a lot of stuff down, but it just doesn't work on the 4th valve. The change in main slide would add about two inches or so to the whole horn and it should make everything more stable.
Just a whacky, fleeting thought.
Roger
"The music business is a cruel and shallow trench, a long plastic hallway where thieves and pimps run free and good men die like dogs. There's also a negative side." Hunter S Thompson
Roger Lewis wrote:Another thing to check are the ferrules on the main tuning slide. I have seen a number of horns that came over with European slides (where the pitch is A=443 or so). If the main tuning slide ferrules are about 3/4 of an inch long and not closer to 2 inches, then you most likely have Euro slide on it and have been successfully lipping a lot of stuff down, but it just doesn't work on the 4th valve. The change in main slide would add about two inches or so to the whole horn and it should make everything more stable.
Just a whacky, fleeting thought.
Roger
That's actually exactly right. I had a band director that had the exact same type horn you (jmerring) had, and it was always pulled waaay out, and he talked to someone from Miraphone at a convention, and got an American tuning slide at no cost to him. So you might ought to consider that...
I think I might end up as a grumpy old man when I get old...
Getting back to the acousticoil: If you want to check for yourself what it does and does not do, just cut yourself a strip of plastic from a thin plastic bottle, and start inserting it (coiled) where you feel like in your tubing. That should show you exactly the results. The acousticoil is a pretty thin piece of plastic, so a thicker piece from a bottle should get you "even more results" than the true article.
My understanding that increased resistance = smaller bore. That having been said; I checked the alignment on the 4th rotor (took the back cap off) and it is (visually) right on. There is an infinetesimally small mark on the rim of the back cap, that I assumed should also be in approximate alignment with a corresponding mark on the exterior of the rotor body. I was not able to find any such mark (a strong magnifying glass was used), so I made my best guess and just put the back cap on, finger tight. I do not have a screwdriver small enough to actually tighten the cap/rotor, but the action is quite fast and the intonation has not changed. I will take it to a tech ASAP, to do it right.
The ferrule on my main slide is 2 inches long, I must make the other assumption that it has the correct length of tubing. The darn thing just will NOT come down in pitch on the aforementioned notes. I suppose that if I had a slide kicker on the main slide, I could force the horn down for those pitches (whenever it would make any difference, i.e., a note played for more than a beat at say, mm=60). Any faster, and those notes are not noticable to our primary audiences.
bloke’s assumption of a too short 4th loop/slide becomes more and more likely.
Do you know how to check slide lengths against open notes? Not that this method is any more exact than the combination of the tuba’s being in tune with itself and of your playing skills.
The length of the 4th slide may be checked by playing F at the bottom of the staff open against the same note fingered 4. If the latter version is sharp, then pull the 4th slide until that F is the same on both fingerings.
I have met very odd tuning patterns in some low end instruments, but I tend to refuse to believe that the low C and the low F are sharp with just about the same amount without the reason being traceable to the length of the 4th valve loop.
