The open-keys soprano is the most sophisticad of the three, thus far.
As in the tenor, the use of only one tone hole per position, was not used. I kept tonehole 13 and 16 and their mechanisms (Ta and Tc) as they were. In the soprano, there is a practical reason for that too. However, I did change the Tf–mechanism, redisgning it to a from a F# to a Gb–function, as I had simply grown accustomed to it this way.
For both the mechanisms for keys 3 and 5 I choose the more efficient switch mechanisms, instead of the spring loaded mechanisms used in the alto. These switch mechanisms are more complicated to build, yet easier to regulate and far more reliable. In the straight soprano I had to cut the tube at two places in order to relocate tone holes nrs. 4 and 5. Tone hole 5 is now in line with nr. 6.
My open keys soprano was made on the basis of some kind of a Taiwanese Selmer SA80-II copy, by the name of Belcanto, a cheap and badly tuned instrument fitted with even the high-G key. I removed it as I found it superfluous. I made a couple of better necks for it.
The slide show goes from top to bottom along the finished instrument.
Key nr 11 (G–G#) is normally a closed key. The third finger left hand operates key nr 12 and because of the closed position of key nr 11 we still obtain a G. Both keys are changed into open keys and now both need to be closed to get a G. Key 11 can be reopened by the little finger left hand through a switch mechanism.
It is not possible to additionally obtain an Ab as a lowering of an A via the bridge between the right and the left hand, such as for instance Leblanc does in the «le Rationnel» saxophone. This option namely is incompatible with the automatic mechanism of the G# and because this G#-function has in the meantime become an integral part of saxophone mechanisms, it was given precedence over the Ab-option.
But it is possible to split the mechanism operated by the third finger and obtain yet another «petit-fingering», this time for an Ab. But since I'm not convinced of the ergonomic correct placement for the extra spatula, it was not (as yet?) executed.
Both keys nr 5 (D–Eb) and nr 3 (the "low C#-key") were changed into open keys. In the straight soprano, practically this had to be solved in connction with one another.
In preparation this also meant that tone holes 4 and 5 had to be relocated in such a way that tone hole 5 gets in line with the rest of the right hand key stack and that more space to construct a mechanism in becomes available between tone holes 3 and 4.
Normally, key 5 is a closed key. The third finger right hand closes key nr 6 and because of the closed position of key nr 5 we still obtain a D. Here too, both keys were transformed into open keys and now both need to be closed simultaneously to obtain a D. Key nr 3 is a closed key too. This one too was also changed into an open key and likewise the two keys 3 and 4 should now be closed to obtain a C.
The lower placed keys of both pairs are driven by switch mechanisms. The one is operated by the fourth finger right hand, the other by the fourth finger left hand in such a way that conventional fingering still applies. The fingerings both for D–D# and for C–C# thus remain the same.
Moreover, when both these operating mechanisms are split, the opportunity arises to add extra touchpieces: an extra «petit» for Eb and an extra Db-touchpiece. And since key 2 links to key 3 (to prevent key nr. 3 from unwittingly being opened when a low-B is taken) the consequence is that from this new fingering for Db you can now proceed to low-B or low-Bb by adding only the fourth finger left hand. Very convenient indeed!
We have to learn to use them, but a number of new fingering combinations are added which come in handy. And since the conventional fingerings remain valid as well, they just form a very nice addition.
Was it worth it? Again, yes. Unlike the tenor I cannot say that the sound of the instrument is now richer and opener or that there is more power to it. Probably this effect is strongest in the larger instruments. But surely the sound is more even in character and, like the alto, the instrument also speaks more nicely at low levels, especially over the greater lengths.
As in the tenor, the switch mechanisms work flawlessly. It turned out well that the instrument was equipped with this kind of mechanisms (even though in the soprano it took quite some effort to construct them) as they are far more idiot-proof than the spring loaded mechanisms used in the alto. Spring tensions are not necessarily higher than in a conventional mechanism and unlike the tenor, in the soprano you cannot feel that there is some more mass to be moved.
Saxophonist Raaf Hekkema played the instrument and was intrigued...