About the spring: tighten it by pulling on the protruding end, but be careful & put some bumper around the horn body part near to the action. If the bearing sits too tight, could cause slowing down the valve action. If the bearing does not sit correctly, also will retard the action. Sometimes the axle needs some "shaving" to fit into the taper of the bearing.
Why dual bore if the (earlier) smaller bore like Viennese bore (nearly) eliminates the sound differences between F- & Bb-side. Yes, absolutely right, quality control is the most important for quality horns. It is cost intensive, if done right (time consuming), so I test my horns in "combat", means in real performances. But that is just possible, if you produce horns in a small number only. Well, these "extravaganza" horns are not made for everybody or purse. Titanium valves must be made perfect, otherwise "eating" into the casings. Sharp bends, 90 degree angles, well, these facts influence the easiness or response of the horn indeed. The main valves (1 & 2 mostly) should "open with the wind" on the horn side which is preferred. It is essential for smooth slures. _______________________________________________ post: [EMAIL PROTECTED] set your options at http://music.memphis.edu/mailman/options/horn/archive%40jab.org
