The Organ

As built by James Jepson Binns of Leeds and installed in 1916, the organ has two manuals of 5 octave compass, and a radiating and concave pedal board of 30 notes.

There are 21 speaking stops, with some borrowing, and as originally built, was provided with a number of fixed of coupler drawstops and combination pistons.

In 2006 a major restoration was carried out by David Wells Ltd. of Liverpool, with the financial help of the Friends of Great Missenden Parish Church - at that time, the decision was taken that the organ should keep the original mechanism, so the action remained as installed - the original tubular pneumatic Binns patent action, together with some mechanical elements, such as the combination pedals and drawstop mechanisms.

However, as the organ approached its centenary year in 2016, it became clear that more work needed to be done - in particular much of the Swell had become unusable because notes were not sounding and the lead tubing and mechanical action were becoming unreliable. Advice was sought from the Diocesan Organ Adviser and various organ builders, and while it might have been possible to restore the original mechanism, it was felt that this would only defer further future significant expenditure; indeed most similar instruments have been converted to electro-pneumatic action to avoid the same issues.

From a maintenance point of view, the chamber is very cramped as Binns managed to fit in a lot of pipes in a small space, which meant that some parts of the instrument were literally inaccessible without dismantling other major parts of the instrument. This also applied in particular to some of the most critical parts of the pneumatic action and the tuning of the innermost ranks.

The decision was taken to convert to electro-pneumatic action, which removed a lot of the more problematic parts of the original mechanism altogether, while retaining the final stage of the pneumatic action. This means that when a note is pressed, the corresonding valve opens to let the air into the pipe(s) exactly as before, so there is no change at all to the integral sound of the instrument.

The new  Solid State Organ control system provides a number of benefits for the player, including the provision of thumb and toe pistons in place of the original mechanical combination pedals, so there is greater flexibility in choice of registration.

This major conversion was carried out by The Village Workshop of Finchingfield, Essex, and was made possible by many kind donations, and was again supported with significant financial help from the Friends of Great Missenden Parish Church.

The specification of the organ

The speaking stops remain as originally built

 
Swell Organ (Left Jamb)

Tremulant to Swell
Oboe 8'
Cornopean 8'
Mixture (3 Rank)
Salicet 4'
Viol d'Orchestre 8'
Vox Angelica 8'
Rohr Flute 8'
Geigen Principal 8'
Great Organ (Right Jamb)

Trumpet 8'
Flautina 2'
Principal 4'
Dulciana 8'
Gedact 8'
No1 Diapason 8'
No2 Diapason 8'
Bourdon 16'
 
Couplers (Left Jamb)

Swell to Great
Swell to Pedal
Great to Pedal
Pedal Organ (Right Jamb)

Bass Flute 8'
Octave Bass 8'
Sub Bass 16'
Contra Bass 16'
Harmonic Bass 32'
 
Octave Couplers (placed centrally, above the Swell manual)

Swell to Great Sub-Octave
Swell to Great Octave
Swell Sub-Octave
Swell Octave
 

The fixed mechanical couplings as originally built were:

Swell Combination Pedals
 
(R to L from left of the Swell Pedal)
 
  1. Rohr Flute 8'
    Vox Angelica 8'

  2. Rohr Flute 8'
    Geigen Principal 8'

  3. Rohr Flute 8'
    Geigen Principal 8'
    Viol D'Orchestre 8'
    Salicet 4'
    Oboe 8'

  4. Rohr Flute 8'
    Geigen Principal 8'
    Viol D'Orchestre 8'
    Salicet 4'
    Mixture (3 Rank)
    Cornopean 8'
General Combination Pedals
Acting on Great and Pedal divisions
(L to R from Right of the Swell Pedal)
 
  1. Gt Gedact 8'
    Gt Dulciana 8'
    Ped Sub Bass 16'

  2. Gt Gedact 8'
    Gt Dulciana 8'
    Gt No2 Open Diapason 8'
    Ped Sub Bass 16'
    Ped Bass Flute 8'

  3. Gt No2 Open Diapason 8'
    Gt No 1 Open Diapson 8'
    Gt Principal 4'
    Ped Sub Bass 16'
    Ped Contra Bass 16'
    Ped Bass Flute 8'

  4. Gt No2 Open Diapason 8'
    Gt No 1 Open Diapson 8'
    Gt Principal 4'
    Gt Flautina 2'
    Ped Sub Bass 16'
    Ped Contra Bass 16'
    Ped Bass Flute 8'
    Ped Octave Bass 8'
 

Playing aids provided in the 2016 conversion:

Divisional pistons
 
  • 6 Thumb pistons for the Swell speaking stops, in the keyslip below the Swell manual
     
  • 6 Thumb pistons for the Great speaking stops, in the keyslip below the Great manual
     
  • 6 Toe pistons for the Swell speaking stops, to the left of the Swell pedal
     
  • 6 Toe pistons for the Pedal speaking stops, to the right of the Swell pedal
     
  • An additional drawstop has been provided at the bottom of the Swell jamb - 'Generals on Swell Toes', which when drawn, changes the functions of the toe pistons to the left of the Swell pedal from replicating the Swell divisional thumb pistons, to instead duplicating the first 6 General thumb pistons
     
  • An additional drawstop has been provided at the bottom of the Great jamb - 'Great and Pedal pistons', which when drawn, causes both the Great thumb pistons and the Pedal toe pistons (those to the right of the Swell pedal) to both operate the Great and the Pedal pistons together - ie pressing Great divisional thumb piston 3 has the effect of pressing Great piston 3 and Pedal piston 3 - pressing pedal toe piston 3 does the same thing.
    If this stop is not drawn, then the Great and the Pedal divisional pistons work independantly
     
  • A rotary switch to the left of the octave couplers, above the swell manual, allows up to 10 independant sets of divisional pistons to be set up - position 1 is the default setup and should not be changed without reference to the resident organist.
General pistons
 
  • There are 8 General thumb pistons provided - 1-4 at the left end of the Swell keyslip, and 5-8 at the left end of the Great keyslip - these are freely settable, and capture the state of both the speaking stops and couplers across the instrument
     
  • There is also a stepper system provided, which works with the General pistons such that there are multiple levels of 8 General pistons - the first 8 appear on the thumb pistons as above as level '1', and the next 8 General pistons - level '2' pistons 1-8 (or 'steps 9-16') will then appear on the same General thumb pistons 1-8. The current level and piston number is indicated on a small numeric display to the right of the octave couplers - the 'level' is shown in green and the 'step' in red. Buttons on this display allow the user to select a level, eg you may have set your voluntary to start from level 10, and sequentially from there

  • To facilitate use of the stepper in performance, there are also '+' and '–' pistons provided, which allow a sequence of steps set in rehearsal, to be progressed through in order, by simply pressing '+' to advance to the next step as required. There is a '+' thumb piston provided at the right end of both Swell and Great keyslips, and a '+' toe piston immediately to the right of the Swell pedal - less frequently required, there is a '–' thumb piston at the right end of the Great keyslip (just to the left of the '+' piston), and a corresponding toe piston immediately to the left of the Swell pedal

  • Further reversible thumb and toe pistons are provided for departmental coupling - in the Swell keyslip, Swell to Pedal, and in the Great keyslip, Swell to Great and Great to Pedal - duplicated on toe pistons
     
  • At the far left of the Great keyslip is the 'Set' setter piston - drawing the desired set of stops then pressing and holding 'Set' together with the relevant General or divisional piston will set that combination onto that piston
     
  • At the far right of the Great keyslip is the 'GC' General Cancel piston - this returns all drawstops to their 'off' position (and of course the actual stop mechanisms) - please use this before switching off the instrument!.
    NB, this does not affect the 'Great and Pedal pistons' or the 'Generals on Swell Toes' drawstops - these remain in their last set position

As of 2016, the action is now electro-pneumatic, the stop mechanisms are directly operated by electrical solonoids - the Swell pedal retains the original mechanical action

Further information about the organ can be found from the British Institute of Organ Studies (BIOS) - the relevant page is their record No N09605