Pitch madness -- insight invited
This really isn't a maintenance issue, but it's not really euphonium specific or tuba specific, and I don't see an obvious topic for it, so I'm throwing it in here. It's a bit lengthy, but I've put a lot of effort into this experiment at this point.
In December I acquired (see sig) a 1924 Buescher 3-valve Eb tuba. I have been working with it since, and the pitch and intonation is driving me mad. I invite any insight and speculation before I apply the hacksaw. I do NOT want to cut this instrument unless I am highly confident that this is necessary and will be beneficial, but it really is driving me nuts after all the time and experimentation I've put into it.
Here's the story ...
I have done the usual leak tests and the horn just doesn't seem to have any significant leaks. It leaks a LITTLE bit through the valves, but I mean that you can just barely force some air through them under significant pressure by blowing through the mouthpiece and with the tuning slide tube(s) blocked. I also mic'd the valves and cylinders and they are all within or close to 0.001" clearance. The horn has a bunch of dents, but no deep ones. Mostly shallow ones on the outside tubing. Some of the valve knuckles have very shallow dents, but that's all.
It is a "small european" shank, and the best mouthpiece I've found for it in terms of tone and intonation is a Wick 5 (heritage style). The second best is a Schilke 60 bass trombone mouthpiece, but this doesn't yield quite the right tuba sound and the intonation is not as good as with the Wick.
I've done repeated "pitch mapping" to see where it is playing sharp or flat, both by myself and then with my wife using the tuner and recording results while I play the scales. This is done from Bb below the staff to Bb above the staff. The results are pretty much described as:
- The Bb below the staff (1+3) tends to be 10-15 cents sharp.
- From B below the staff through the D, it tends to be about 5-15 cents flat.
- The open Eb is in tune.
- The E and F are quite sharp (around 20-30 cents for the E; about 10-20 cents for the F). The E is 1+2+3 and the F is 1+3.
- In the staff from G through Db, the horn tends to play from 15 to 30 cents flat.
- From Db up to the Bb just above the staff, the horn comes closest to playing uniformly in tune, but still around 10 cents flat for the most part. But the open Eb is right on.
During this experiment I did my best not to "lip" notes one way or another but to play with a comfortable embouchure that seemed to produce a nice tone quality. And this was with the tuner set to A=440.
If I set the tuner to auto-tune and play an A, it settles on 435. If I play a Bb, it settles on 462. This seems the most compelling evidence that the horn is pitched to something lower than A=440, probably A=435. It has "LP" stamped into the second valve casing, indicating that it is a "low pitch" instrument, but as I've remarked in another thread, "low pitch" was highly ambiguous in the early 20th century. The thing that bothers me about this fairly obvious conclusion is that the open low Eb appears to be in tune (if I'm not unconsciously correcting to that). On the other hand, with the tuner set to 435 I can play the low Eb, the Bb, and the Eb in the staff in tune with ease as well.
I measured, as accurately as possible, the lengths of the valve circuits, and these appear to be in the correct proportions for the half step, full step, and 3 = 1+2 configuration.
Here are my alternatives going forward:
- Keep the horn as it is, use it for a "Tuba Christmas horn", lip everything or pull slides as necessary. Give up on using it for concert band or decent small groups.
- Try to find a magic mouthpiece that will make everything perfect. (Okay, this isn't actually a sane option. Just thought I'd include it for laughs.)
- Say, "Well, the horn clearly is pitched below 440. Cut the main tuning slide and go from there, cutting valve slides if really necessary but hoping not."
- Say, "Well the open horn plays to pitch. Cut the tuning slides to get the rest of the notes in tune."
At this point I'm leaning mostly towards either 1 or 3. I would REALLY like to get a horn that I can play with confidence (and not excessive effort) in a number of contexts. I don't like the idea of cutting it, but the results of the mapping and particularly the auto-tune experiment do seem to indicate that it's not a 440 instrument.
I am open to insight, thoughts, wild speculation.
Last edited by ghmerrill; 02-01-2013 at 02:53 PM.
Reason: Typos on mouthpiece size and tuning notes.
Gary Merrill
Wessex EEb Bass tuba (DW 3XL or 2XL)
Mack Brass Compensating Euph (DE N106, Euph J, J9 euph)
Amati Oval Euph (DE 104, Euph J, J6 euph)
1924 Buescher 3-valve Eb tuba (with std US receiver), Kelly 25
Schiller American Heritage 7B clone bass trombone (DE LB K/K10/112/14 Lexan, Brass Ark MV50R)
1947 Olds "Standard" trombone (Olds #3)