. . . So the maximum power on this organ can be achieved by drawing open diapason, lieblich gedackt, dulciana, mixture and bourdon 16?
thanks for your help
Yes ... except leave out the Dulciana as it will do nothing to add to the full ensemble. You can experiment around with playing the left hand where it belongs and playing the right hand an octave higher to get a little more brightness possibly ... use some trial and error in practice sessions. You can also use the Swell shades to good advantage ... maybe open them 1/2 or 3/4, and then go full open for a final verse and/or add the Mixture rank.
There is only so much "oomph" one can get out of 5 ranks ... I know from firsthand experience, and in my present case at my church, there is so much that II/9 can do, too - although my organ tech says I make it sound like 15 ranks (for tutti with all the 16' stops drawn, I'll sometimes play both hands an octave higher).
I played for years on a Wicks unit organ ... it was originally installed in a theater and comprised 13 ranks, but the church got the console and 5 of the ranks, including the Xylophone (which was never hooked up). The wind pressure was at 15" ... and the 5 ranks were 8' Diapason, 8' Melodia, 8' Tibia, 8' Vox Humana and 8' Salicional. There were stop tabs for all these at 16', unison, and 4', typical of theater organs that are mostly unified anyway.
For hymn and service playing, two ranks were all that were useable ... the Diapason and Melodia. The Tibia was too "hooty" and could never be used to play block chords on, but it was useful as a solo stop. Because of the high wind pressure, the organ required monthly tunings and maintenance ... after the organ tech died, I took over the tuning and repairs myself. I then re-voiced the Vox by closing the top caps completely, and tuned it sharp to the Salicional ... a quasi celeste ... albeit a strange sounding celeste, but none-the-less there was finally a use for the Vox rank.
In later years, I swapped the Tibia rank for a 4' Cornopean ... for the first time, the organ could be heard at the back of the church!!
I played that piece of junk for 7 years - it was a fun experience, one that I'll never forget ... especially the ciphers that would occur all by themselves ALWAYS right in the middle of a quiet prayer or pause in the pastor's sermon. The only cure was to go up to the chamber and pull the pipe and fix it later. More than once I had to stuff a heavy rag into the mouths of the lower pitches of the Melodia rank. We finally replaced it with an Allen Digital (600-DK) and sold the pipe organ for $500.
Two of those ranks (vox and tibia) were theatrical ranks and hardly suitable for church service playing - although in later years, I re-voiced the Vox by closing the caps on the pipes and then tuning them slightly sharp to the Salicional, creating a quasi celeste - a strange sounding celeste, but with the trem on, it wasn't bad. The Tibia was way too "hooty" to use for anything but as a solo stop, so for hymn singing I had 3 ranks basically.