Posted by Chuck on August 28, 2000 at 21:36:59:
In Reply to: Compensating system. posted by Wants to know more on August 28, 2000 at 08:30:32:
Think about it this way--on a 4-valve Eb compensating tuba, depressing the 4th valve not only adds enough tubing to effectively change the horn into a BBb instrument, but also adds extra length to each slide so that intonation remains correct in BBb. i.e., if you push the 4th valve down on an Eb tuba, you really HAVE changed it to a more-or-less anatomically correct BBb.
Three valve compensators do the same thing with the 3rd valve, but can only adjust the lengths of the first two slides. So by pushing the 3rd valve on a 3 valve Eb compensator, you wind up with a 2-valve CC tuba...