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I have a Conn 56J and some minor intonation issues in the lower register (Tends to be sharp). I have been pretty successful with some alternate figerings, but I have reason to believe that a larger rotor may solve the problem. Any suggestions?

Specifically which notes are you talking about?

E down to Db. *FYI* All manufacturing soldering globs have been removed from the horn.

E (fingered 2+3+4) doesn't involve the 5th valve. What fingerings are you using for each of those notes?

Eb (5+3+4)
D (5+1+3+4)
Db (5+1+2+3+4)

I had to re-port my Conn's 5th valve; changing the rotor will not make the difference you seek, but getting that bad boy scoped to perfect porting could help a lot; make sure the other valves are on too, as I've seen those and their King cousins shipped with the felts reversed or incorrectly chosen.

Also, F on those is 124, push in 1. Balls on. Then you can have a nice Db 235; after low F, all tubas tune a bit differently down there.

YMMV (apologies to Mr. Baer who doesn't like 5th valve use in this manner).

J.c.S.

Kevin Lilley wrote:Eb (5+3+4)
D (5+1+3+4)
Db (5+1+2+3+4)

Those are all quite normal.

Do you tune the fourth valve length to D or to G ?

cjk wrote:Do you tune the fourth valve length to D or to G ?

My fourth valve is tuned to G.

The CC tubas I have owned have varied a bunch down in that register. I've had 2+3+4 low Es that were sharp or dead on or flat. If I were you, I might try some of the following stuff if you haven't already:

* play E 1+4+5 and monkey with the first valve slide if necessary
* play Eb 1+3+4 and pull the first slide way out or 1+2+3+4 and possibly push a slide in.
* A mouthpiece with a larger throat. Maybe a G&W Bayamo? Possibly a larger throat plus a smaller inner dimension like a G&W Taku?

If you push too hard on the mouthpiece, those notes will go sharp (or sharper as the case may be). You might be trying too hard. Try to relax more when playing down there and use lots of air. When I go sharper in the lower register (usually when I'm playing loudly), I find that it's useful to concentrate on using as little pressure as possible. When I do that, the notes I'm worried about get flatter. Hopefully some of this is useful to you.

In the end, your tuba could just be that way and you'll need to pull the 4th slides while playing. For example, if you find videos on Youtube of Gene Pokorny playing, you'll seem him moving both the first and 4th valve slides quite a bit. On my CC tuba, 2+3+4 low E is fine, but 2+3+4+5 low D is too sharp and 1+3+4+5 low D is too flat, so I play low D 2+3+4+5 with a big 4th slide pull.

hope this helps,

Christian

Kevin Lilley wrote:I have a Conn 56J and some minor intonation issues in the lower register (Tends to be sharp).

I find the entire horn to be about 2 semi-tones sharp.

Alternate fingerings definitely help.

Very insightful! I will try to piddle around some more on the horn when I get home tonight. I know that I have had some air-direction problems when it came to the lower register. But, through some breathing exercises with the mouthpiece and the help of a low etude book I have filled out the bottom of the horn a lot more.

IF it were to be an issue with the rotor how would one go about getting this fixed. I know from the previous owner and myself that there tends to be a lot of back-pressure from the rotor. This is why I mentioned getting a larger one. Try as I might on my D and Db there is simply too much resistance. Any more suggestions?

Kevin Lilley wrote:Very insightful! I will try to piddle around some more on the horn when I get home tonight. I know that I have had some air-direction problems when it came to the lower register. But, through some breathing exercises with the mouthpiece and the help of a low etude book I have filled out the bottom of the horn a lot more.

IF it were to be an issue with the rotor how would one go about getting this fixed. I know from the previous owner and myself that there tends to be a lot of back-pressure from the rotor. This is why I mentioned getting a larger one. Try as I might on my D and Db there is simply too much resistance. Any more suggestions?

On this model, the 5th is removable. Have your tech take it off and actually look at the porting and adjust the stop arm bumpers accordingly. The hash marks lie.

Also, when he/she puts it back on, be sure the thread connection is sealed. I used rubber cement on the flange and that actually made a big difference for me; also make sure your leadpipe is screwing flush to the valve casing; an all-too common problem is Conn having used leadpipes which were cut too short (?!?)

J.c.S.

One thing to keep in mind with ANY 5 valve contrabass tuba: once you get into the very low register near the pedal, not every note will be in tune simply by pushing the right buttons. There will have to be some degree of lipping and/or slide manipulation. This is just due to the nature of having 5 valves; to truly get all notes closer to in tune, you would need 6 valves, as on many F tubas. Fortunately, most notes in that range have very wide slots, and we don't spend enough time down there to really make it an issue. You could also see how the false tones work for you in that range.
You can also try "relaxing your air" if you are consistently going sharp down there, and dropping your jaw more.
Hate to say it, but this could wind up being one of those "ask your teacher" moments.

Do check that your fifth valve rotor is aligned as perfectly as possible. When I take my 56j apart for deep cleaning it can take a couple tries until the rotor is aligned well. I have found that even being a little bit off has a very large effect on the playability of the horn. But when I get it just right the tone opens up and the intonation improves.

Also, if you set your 5th valve so F T+4 is in tune, this will be too short for lower notes and will need a pull.

Awesome advice from everyone!!! Thanks to all that replied!

J.c. Sherman wrote: The hash marks lie.

This is so true. Visual inspection is the only way to go.