Converting a Bb or Eb instrument to C

AlbertR

New Member
I play with a folk group and for this and other reasons I would like an instrument in C (after decades of bass and trombone, a C trumpet would be out of my capability). Not being able to find a suitable instrument, I am now thinking about converting a Bb baritone by taking away appropriate lengths of tubing (lead tubing and valve tubes?). I think I will be ok with the necessary plumbing skills, and it is an old instrument I am think of converting anyway, but has anyone any thoughts on this?
(I have an old Eb horn that could, alternatively be added to but for reasons I am not sure about the Bb baritonr to C might be easier)
Any suggestions and thoughts will be appreciated.
 

2nd tenor

Well-Known Member
Some Trombones are available in C and in a way that’s an easy option (eg. John Packer JP138 Bb/C Trombone).
Some folk also just learn a new set of fingering (or shifts) to play what they have as if the instrument was build in a different pitch.

Cutting a Baritone would be the easiest way to get a C valve instrument. I guess that you’ll be looking at removing a section of main tubing near equal to the first valve leg length and then trimming the valve legs in proportion. It shouldn’t be two hard to work out dimensions but someone like Moomin Dave will know them and you’ll need to talk the practicalities of your proposal out with your Brass Technician. Of course cutting an instrument might introduce unanticipated problems in the way it plays and/or responds.

Cutting up an instrument will cost money and leave you with something of doubtful (but low) resale value.
 
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AlbertR

New Member
Thank you for the reply. Very useful. I am tempted by that trombone, I see there is a C valve trom too that might be good.

I have thought about learning the transposing fingering and use a standard Bb/Eb. Maybe I have got lazy?

If I was to go for the arduous task and likely not too successful of butchering an instrument, I would be the erm, 'Brass Technician'. I realise there are technical matters to be considered here, regarding things like node points etc, but it was a thought.


Edited to add:
£399 in vat.......very tempting
 

MoominDave

Well-Known Member
I log onto TMP for the first time in a week or so, and find that someone mentioned my name five minutes before :)

Chopping up a baritone at home (unless you have significant instrument tech skills) would be a great way to end up with a terrible baritone that doesn't even do the job you want very nicely and has only scrap value to anyone else... For the record, quick calculations suggest you'd need to lose the following amounts of tubing (i.e. half this amount from both sides):
Main slide: 32 cm
1st slide: 4 cm
2nd slide: 2 cm
3rd slide: 6 cm
If it compensates, then those loops would need reducing too - but I bet they would be too small to do so. Even the straight portion of the 2nd valve tubing might not be long enough for it.

The old Conn "Preacher model" trombone was pitched in C. But these are rare, and production was discontinued in 1932 (the link says). Plus they had a peashooter bore of .458", so would be a bit of a blowing surprise to most modern players.

I would suggest buying one of these, if learning the transposition is too hard:

I would personally just mentally transpose the music... Up a tone is about as easy as transpositions get.
 

AlbertR

New Member
Hi Dave,
A magical reply. Thanks.
I 'edited to add' to my previous post and am currently looking at the JP C valve trom (but it is out of stock). The link you provided is a good 'un.

I have spent a lifetime transposing with bass trombone (including G...!) and tenor trom in brass bands, orchestras etc, and yes, it would be the obvious route. However, I find myself with no brass instrument at all and I thought if I acquired one again, then I may as well go with a C instrument.

I fancied the challenge of converting an old instrument myself but I shall reread the above posts each time I think about that again.


Edited to add: C Valve Trom - Wessex or JP?
 

MoominDave

Well-Known Member
Both Wessex and JP are Chinese imports, and they likely ultimately come from the same factory! The added value is in the QA on this side. Both companies have a reputation for doing that quite well.

I must confess that when I play G trom, I mentally move the music down a line on the staff, add a flat, and pretend I'm in transposing treble clef, adjusting accidentals on Bs...
 

Neil Edwards

New Member
Over the years, I must have converted around a hundred mainly student grade trumpets from Bb into C and some even to Eb/D. It's all about getting the proportions right. For Bb to C you need to think 8/9 ths for main tubing and slide loops. Ideally, you also need to consider reducing the main tubing at more than one point so that that you don't disrupt too much the ratio of parallel to conical bore. Depending upon the wrap, this can be difficult. I have also converted a few Eb horns into F altos for concert band work. A few years ago, I bought one old 3 valve Weril euphonium to cut down to C for the purposes of making life easy reading bass clef parts. That particular instrument I also added a rotary switch valve salvaged ffrom a bass trombone to allow conversion back to Bb. Photos an Eb/D trumpet conversion I have done, and the Weril euphonium I converted into C/Bb. This was relatively easy because of its long main tuning slide in front of the valve block. Always choose an instrument with a convenient wrap!
 

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AlbertR

New Member
Hi Neil,
Well what can I say!That is a very informative and stunning reply.
So converting to C is achievable enough then, but I'm not sure I have the time to step onto the learning curve. And there must be some degree of trial and error in that.
Could I ask, do you have C instrument to sell? Or even better a C/Bb?
 

Neil Edwards

New Member
Hi Albert,
If you wanted to have a baritone cut down to C, something like this Lafleur Bb (made for B&H by Amati or B&S) open wrap one would be relatively easy to convert. I would measure up carefully to begin with and then unsolder and cut down the top bow about 10cm and reduce the main tuning slide initially say 5cm. so that altogether you lose about 30cm in total. The final trim to the main tuning slide is bit at a time until you reach just the sharp side of C. If memory serves me correctly, you then want about 18mm off the first valve slide, 9mm off the second valve slide and about 27mm off the third valve slide. If you take a bit too much off these, it's no disaster. You can always pull the slides out a few mm to tune up. I've nothing I want to sell at the moment, but I could keep a lookout on ebay and see what comes up.

I've just spotted that Thomann sell a C valve trombone for £315. It might be what you need.
 

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AlbertR

New Member
Well....with the ease of the internet and one click of the mouse it would seem I am now the owner of a Thomann MB-20 C Valve Trombone (Yay!!!)

I guess I'll just have to put my pipe cutters, files and paraphernalia away and spend that time I would have spent doing a conversion into learning a few folk tunes to play at the local pub folk session.

Cheers all!
 

AlbertR

New Member
I didn't want to speak to soon - but yes happy days indeed. Like a kid at Christmas. The instrument was delivered a couple of hours ago and I have been at it non-stop since then. After a decade or so of not playing my lips are a bit shot.

A few tuning issues, but they should be ironed out once I get my lip back in.

The instrument is well worth the money. I love it already.

One day I will have my Bb to C project, but meanwhile, right now, there is learning and playing to be done.

Thanks all, but especially to Neil for the link to the trom.
 
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Richard Knock

New Member
Thank you for the reply. Very useful. I am tempted by that trombone, I see there is a C valve trom too that might be good.

I have thought about learning the transposing fingering and use a standard Bb/Eb. Maybe I have got lazy?

If I was to go for the arduous task and likely not too successful of butchering an instrument, I would be the erm, 'Brass Technician'. I realise there are technical matters to be considered here, regarding things like node points etc, but it was a thought.


Edited to add:
£399 in vat.......very tempting
I play trumpet and clarinet in a number of jazzbands where the keys commonly used are called by concert pitch (e.g. a brass band C on a Bb cornet is called Bb) Many tunes in the jazz repertoire are commonly pitched in Bb,F, Eb,C, Ab, Gm, Fm, and some others.
It means respectively, C,G,F, D,Bb,Am,Gm, in brass band terms, So pretty straightforward really though it can do things to your brain when you play in both genres. The only unusual ones are learning to be fluent in the brass band keys of D and Am, which a few weeks of practice will soon sort out. Scale and arpeggio practice is the answer and it gives you freedom.
 
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