The organ has 63 stops spread over 4 manuals (58 notes each) and a 32 note pedalboard. Each division has its own function and can be seen on the organs façade, with the exception of the Récit.

The centre part is crowned by the Grande Orgue, based on a 16´ Principal. Below that, above the console there is the Solo division, enclosed in a swell box, except for the horizontal trumpets which can be easily tuned from the spacious gallery and also has room enough for several singers or instrumentalists. The Positif is actually below the organist. Behind that, moving into the side aisle, we have the Récit.

The pedal stops are located in two independent towers placed over the adjoining arches. This way the full weight of the instrument – 30 tons – is distributed over the buildings four columns. Each Tower is divided into two levels; the upper one contains the first octave of the larger stops: Contre-Posaune 32',
Principal 16', Soubasse 16' and the Grosse Quinte 10 2/3'.

All the manuals are suspended tracker action. The valves have been constructed so that all the pipework get their wind supply from the soundboard, without making it harder to play on the manuals. The trackers even reach the Pedal Towers by using a special thin wire, that make them almost invisible from below.

Six large bellows, five of them wedge-bellows, get their wind supply from the wooden windtrunks which lead to the individual divisions. The stop action is controlled by electric magnets with a capacity for 5,000 combinations; these may be programmed from a computer.

Acoustical tests were done in the Cathedral in order to confirm the measurements, alloys and wind pressures, etc.; the voicing process could then begin, first on a voicing machine, and then later in the mounting room.
A small margin was prudently left before establishing the instrument final pitch.

It is quite hard to express what we mean by a style of voicing if we are forced to put that into words. The aim was to get precision and transparency out of each note, for each pipe in every corner throughout the entire church. Since we were dealing here with a Cathedral, an energetic sound was called for, one that would fill the large space involved. However, the instruments excellent placement allowed us to, or rather, demanded of us a delicate voicing that is clearly discernible on the 7 CD recording of this organ now available.

We tried to get each pipe to speak quickly at its fundamental pitch; we studied the important and delicate balance between the foot, the flue and the height of the mouth. We think the pipes speak cleanly and quickly, attacking the fundamental without any undue delay. This way, the organ is capable of performing a wide range of musical literature, even the Romantic repertoire. The reed stops all have contrasting characters, some more Germanic others more Latin, and as a homage to the Flemish Masters who contributed so much to 17th century organ building in both France and Spain, we have included a trumpet on the Positif in tin plate.

Finally, this instrument is proof that the outcome of anything is the result of a willingness to do the job, plus the combined effort and contribution of each and every member of a team.

All the manuals are suspended tracker action. The valves have been constructed so that all the pipework get their wind supply from the soundboard, without making it harder to play on the manuals. The trackers even reach the Pedal Towers by using a thin special wire, what does make it almost invisible.