sc_curtis wrote:But if the tuba in question is a fantastic tuba, with really great response, intonation, and sound, why mess with it at all?
That happens very rarely. If the tuba is that good as a BBb, then it's too expensive to be worth cutting.
Consider the cost of converting an instrument to C. You'll have to overhaul the instrument, make the conversion, add the extra valve, and apply a new finish. With many, you'll have to replace the valve block. A great BBb tuba, even in so-so condition, will sell for more than $4000, and when you add the cost of the above, you have a cut tuba that will not sell for the price it must fetch to pay you back for all of the above.
Cutting makes the most sense for tubas that are otherwise unsellable, where the valve block is ruined and must be replaced anyway, and where the outer branches (what Joe is calling the main bugle) are particularly useful in a CC for one reason or another.
So, if the instrument is good enough as a BBb to fetch more than about $2000, it isn't in danger of being cut unless someone just wants to do it to their own horn and don't care what it costs.
Rick "whose BBb Holton might have made a great C but it was worth too much as a BBb to make it worth it" Denney