The organ of the H. Antonius Abt was built in 1927 by the firm of Jos Vermeulen from Alkmaar and had tubular pneumatic action to begin with. In 1952 the specification was drastically revised by Vermeulen and the swell box for the 2nd manual was removed. In 1984 the organ was in need of attention and repairs were carried out by Vermeulen and again in 1992 by Flentrop from Zaandam.
At the end of the 90’s the organist Gerard Legierse had the Quint 1⅓’ moved up to a Terts 1⅗’ on the 2nd manual. In 2002 the action was electrified by the firm of Pels & Van Leeuwen from ’s-Hertogenbosch. Further adjustments included: the Zachtbas 16’ was restored as a transmission from the 3rd manual; the voicing of the Resultantbas was tweaked; a Setzer sequencer was installed with 128 memory steps and octave and suboctave couplers were added.
The current specification of the organ is as follows: