Hi John,

First let me comment on the upside down primary valves in the stack. I have not dismantled the stack (I hope not to need to do this and will seek to repair all the other obvious faults before making that decision) so I can't be certain what is inside, but looking closely at the outside of these valves, it seems clear that they are held up by an external little leaf spring. This area is hard to photograph but I attach one which I think shows this. (Photo 1)

Photo 1 - Upside-Down Poppet Valves

The MELODY lever is, as you noted, spring loaded and to the right when not used. It operates, via a shaft, a slide valve (Photo 2) which switches two control lines between atmosphere (at rest) and two holes on the outer end of the tracker bar when the lever is operated. I do not think I understand this mechanism and have tried to draw the parts schematically. If what I have drawn is correct it looks to me as though the regulator pneumatics are bypassed when the melody lever is unused (the large valve beneath the pneumatic will be open allowing vacuum to flow to the stack without the conical valve controlled by the pneumatic to impede the flow. When the lever is operated the large internal valves will close allowing the regulators to operate (assuming the tracker holes are closed by the roll) except when a hole in the roll causes the valves to open and hence provides some louder emphasis. Could this be a form of Themodist mechanism? (I have of course only read of this and never seen one). I am troubled at the conclusion that the regulator pneumatics are effectively disabled unless the melody lever is held to the left, and perhaps I have drawn this incorrectly, but at present I can't see that I have. I attach my drawing of this mechanism and a few photos of the components involved.

Trackerbar & Melody Switch Tubing Diagram

Photo 2 - Melody Lever & Switch

Photo 3 Three internal valves the lower is cut-out and the two upper control supply to the two regulator pneumatics.

Photo 3 - Cut-Out and Regulator Valves

Photo 4 The outside of the valve assembly (Photo 3) with the manifold which attaches control lines to loudness pneumatics, vacuum cut-out and the two regulator primary valves. Bleeds for regulator primary valves and the cut-out valve can be seen.

Photo 4 - Outside of Manifold for Cut-Out and Regulator Valves

Photo 5 Shows the main vacuum chamber with the valves removed, The primary valves for the two regulator valves are above and between the two regulator pneumatics. Internal channels transfer the primary output to the large secondary valves. The holes leading to these channels can be seen below the primary valve assembly.

Photo 5 - Valves in Photo 3 fit into Slots in this picture

Photo 6 Shows the RH loudness valve and how it connects directly to the main vacuum chamber. (Notice it's location in relationship to the medium-size bellows -top left of picture. This is the same bellows that is seen in Photo 5 -top right w/conical-shaped valve removed.)

Photo 6 - Right-hand Side Loudness Valve

Photo 7 and Photo 8 Show the physical arrangement of the regulator pneumatics.

Photo 7 - Regulator bellows and Restrictor

Photo 8 - Primary Valve and Pneumatic

Photo 9 and Photo 10 show the two ends of the tracker bar, The outermost small holes go to the tracking pneumatic, the large square hole at the left end goes (via a switch ) to the sustain pneumatic, and the two narrower slit like holes go via the melody slide valve to the two regulator mechanisms.

Photo 9 - Trackerbar Left Side

Photo 10 - Trackerbar Right Side

I am sure this will be far more easily understood by you than me and would value any comment or correction of my thoughts you may have.

Regards

John Morris

John had previously sent some pictures which add a little more dimension to the player system. They are shown below with brief explanations.

Exhauster Assembly with Reservoirs on the front side of the assembly. Also shows the orientation of the regulator valves and bellows. Exhauster bellows are on the back side of the assembly. The rationale for having three valves to operate one expression bellows is unclear.

These are the operate controls in front of the keys. They might shed a little light on purpose for the three valves per expression bellow. Note the two buttons marked "Bass" and "Diskant" (or Treble). The "PP" between the buttons indicates that they are for decreasing the volume of the music. In fact, looking a little closer at the two valve boxes the are mounted to the left and right of the Expression bellows, note the size of the tubing (see Photo 6). Not look at the picture below. It is the Treble Soft Pneumatic. This pneumatic is connected via linkage to a secondary hammer rail (which is behind the regular hammer rail). It is known as a "Split-Rail" because it moves all of the hammers, from the middle of the keyboard to the highest note, closer to the strings. This effectively decreases the 'strike' (or blow) distance, which decreases the volume of the music. So, the "Bass" and "Diskant" Pushbuttons operate the Bass and Treble Soft Pneumatics. Therefore, they have nothing to do with the "Melody" lever or the Expression bellows. (One mystery solved.)

Treble Soft Pneumatic operates Split Hammer Rail to reduce the volume of the music.

Lastly, after considering everything, I'm inclined to think that the Theme holes in the trackerbar are channelled through the Melody switch such that the holes in the trackerbar will allow a signal to pass through to the expression valves when the Melody switch is in the 'relaxed' position. If that's the case, then activating the Melody switch manually would allow the user to manually add accents to the music.