However, she was adamant that the first person to play it will be the cathedral's organist Gary Bowler.
"It will be Gary - he will play at the first service."
That service will be the dedication of the organ in the first week of April and will be led by Bishop David Rice.
Bishop Rice had been "very hands on" in helping out with the heavy work at the start of the installation, Dean Jacobi said.
The assembly and preparation crew are about three weeks into the installation and "voicing" of the refurbished and revitalised pipe organ.
"It has all been going very well, no real issues at all," said Gerald Green, the South Island Organ Company's tuning and maintenance technician.
"Oh, (there are) a couple of little things but we've been doing this for so many years they are not really an issue at all."
The altar end of the cathedral is now clad with scaffolding as three technicians work away on the installation.
Dean Jacobi said the scaffolding had led to some reshuffling around services, but said church staff and parishioners had come to regard it as "camping, cathedral style".
When work started on January 16 there were six workers on site, but as Mr Green explained, the early stages were all about placing the large, heavy-lift, components.
"There are something like 3700 pipes in the organ - the largest is 32 feet long and the smallest about three-quarters of an inch," Mr Green said.
The refurbishment and re-installation was one of the biggest jobs the company had taken on since setting up in 1968.
"It is definitely right up there - as large as they get in New Zealand," he said.
He added that the St John Cathedral organ would be unique in that the custom-built "European" style playing console was the first of its kind to be created for a New Zealand-based organ.
The only others built had been two for a cathedral in Western Australia.
"This is going to be world-class when it is completed," said Mr Green. "We will customise the pipework to the acoustics of the building - called "voicing and finishing."
The installation is the final stage of a $745,000 refurbishment project which began in January last year when the organ was dismantled and dispatched to the Timaru-based company for a complete overhaul and rebuilding.