____BBb____________CC___
EBAY PHOTO
Ignore the 5th valve; BBb and CC tubas have both been available with both styles of 5th valve, and with no 5th at all. The difference between a BBb and a CC would be indistinguishable in this photo.
Instead, notice the difference in the tubing as it exits the valves -- the dead give-away on Miraphone 18x's between BBb and CC models. In the CC tuba the tubing exits the valve cluster, comes down and executes a simple 90-degree bend to the viewer's left, directly into the tuning slide. In the BBb tuba, it first bends about 45 degrees to the viewer's right, then 135 degrees left before the tuning slide. The same difference occurs above the valve cluster, although it is difficult to see the simple 90 degree bend in the CC tuba because of the 5th valve.
Also, notice the difference in ratio of length/width of the body of the instrument. The BBb is somewhat longer, like the instrument on ebay. Finally, note that the CC tuba leadpipe is almost exactly at the height of the top bow, while the BBb tuba is a bit below the top bow -- again, like the ebay pic.
Please have a look at your CC, and at the ebay photo, and see if my observations aren't correct.
______________________________
Joe Baker, who is pretty sure he's right on this one.
