Posted by Klaus on February 15, 2001 at 13:07:21:
In Reply to: Re: 6-valve FRench trombone by Sax posted by Wow! on February 15, 2001 at 09:53:32:
You might be right, but within the frame of thinking behind this construction you are missing the point. The idea was to avoid the inherent faults of adding valve crooks, that are in tune on their own, but not in combination. Hence a separate valve covering each interval needed to fill the fith between the 2nd and 3rd partials.
On standard 4 valve instruments the intervals of minor and major second, minor third, plus fourth are covered by their own tubing lengths. The major third is thought to be covered OK by the 2+3 combination (and I agree in that).
But when further valves are added, they are not producing in tune intervals, if they are used alone by themselves.
The length of the 5th valve is usually determined by one of two criteria: It shall lower notes played 4+5 a major second from the notes played by 4. Or the lowering can be that of a minor third.
In case of the 6xt valve the criterium is a lowering of a minor second of notes played by 4.
So this makes all valves (on standard instruments) numbered higher than 4 out on tune if used alone.
But the idea of the Sax valve trombone is as seen that each valve should provide in tune lowerings of minor or major seconds, minor or major thirds, fourth or tritone.
From 1 or 2 valve bassbones we know, that when any valve(-s) are involved, positions mostly leave the normal 1st through 7th positions.
Klaus