Conn 28A long cornet questions

[romajore]

I recently acquired a 1961 conn 28A. A conn 4 cornet mouthpiece came with it. That mouthpiece inserts 1/8 to 3/16 further into the horn than my cornet mouthpieces. The difference in gap makes it slot and play better. On most horns, I would just move the receiver to allow my modern mouthpieces to play more efficiently. However, as I understand it and from looking at the horn, it appears the receiver is an integrated part of the lead pipe. Has anyone else dealt with this? What options/solutions are available.

Second question for any 28A players is what mouthpiece do you use to sound like a trumpet? A cornet? A flugelhorn?

Thanks in advance for your advice.

[Rompson]

My first thought is: are you sure it is a a 1961 and not earlier? Early Conns used a different, shorter shank with a different taper.

My next thought is that whatever mouthpiece you are using is just a bad match for the horn. IME with Conn cornets is that the gap matters less as they don’t have a distinct “shelf” in the receiver like trumpets do.

[Andy Cooper]

Spend a little time on the Conn Loyalists Website

https://cderksen.home.xs4all.nl/ConnArticle34.html

While some Conn Cornets and Trumpets are "gapless" they still have a point where the leadpipe entrance is at it's narrowest. The distance between that point and the end of the mouthpiece shank and the thickness of the mouthpiece shank still affects my playing.

The "gap" may be one factor, throat size and length and thickness of the mouthpiece shank another factor. I'm looking at an old Conn #4 and it has a some what long throat which I don't see in a Bach 7C.

Conn #4 cornet mouthpieces are not really collector items so you could just have one cut and threaded to take a top of your choice. Should run you less than $50 which would be better than damaging a one-piece copper leadpipe and cheaper than a custom backbore.

Perhaps Lipshurt might chime in - he has a lot of experience working with mouthpiece shanks for Conn instruments.

[yourbrass]

The Conn system was a three-piece arrangement- receiver and leadpipe, and a tube that was over them. You may or may not have a "short shank" receiver, which was different from what they made later.
So the main problem is getting the right shank, and working with gap - there is one generally.
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[romajore]

Thanks all for your responses. It is a 1961, based on serial number and the valve design. The lead pipe has a “shelf”, like my trumpets. The Conn 4 mouthpiece is a long model. The taper on the Conn mouthpiece shank is faster to a narrower end than on my modem cornet mouthpieces creating a smaller gap, which plays better for me. Anyone have specific experience shaving a shank down or putting sleeves on a cornet mouthpiece? If so, was it effective or did it change the way the mouthpiece played?

[lipshurt]

the conn 4 is not a different taper, but it is a bit smaller than most (not all) bachs. The long shank conn 4 has (might be wrong off the top of my head here) a O.D. of .342 compared to "most" of about .346. That will give it about one "sleeve size" smaller gap situation.

That conn pipe is a one piece electroformed copper pipe and the receiver does not come off. Its also a great pipe. The best horn i ever payed was a 28a with the one piece copper pipe. I never owned one with that pipe, but i do have a 28a with the earlier 3 piece pipe with the gapless venturi setup. On that horn i worked long and hard and made at least 20 shanks and backbores and came up with some conclusions.

Surprise surprise the best O.D. was .342 to .345. The best backbore for a 3c cup was long shank with an extra .060 of throat length (added by increasing total length to 2.810) which got the upper octave down, and also helped the response.

For a deep V style cup, the best setup was the same shank diameter but shorter total length to "short shank" 2.5 inches. That got the upper octave UP to where it should be. The deep V lowers the upper octave a lot.

I would say that the 28a i had worked better with at least a 3c type depth.

If you want to hear how good that horn can sound listen to the early Thad Jones small group records like The fabulous That Jones or the magnificent That jones, Mad Thad etc. Awesome
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[romajore]

Lipshurt - thanks for this additional information. FYI the OD on my conn 4 measures at .341 and my GR at .345 on my inexpensive digital calipers. I look forward to experimenting and finding the best fit for me. It’s a fun horn to play.