Posted by Max Tunnell on January 11, 2001 at 00:07:43:
In Reply to: 4th valve added to Imperial? posted by Kaseem on January 10, 2001 at 17:50:38:
As I understand it, the three valve and four valve compesating systems are different. You would not get the results you expect ie. a chromatic range extended to the pedal register.
There are explicit instructions as to when to use the fourth valve and when not to use it to be sure to compesating system is working properly. My old Boosey and Hawkes four valve looks pretty different than the three valve model around Valves 1,2,and 3. for some combinations the fourth valve changes the routing of the tubing depending on if the 4th valve is used.
I don't think it would do you any good at all!!