Nowadays he produces music with local artists and puts them on the map.
Johnson describes the process of making music as a "wonderful adventure", a journey over the course of a year, seeing the artists most weekends, "and you just become friends".
He says he finds relief once he knows they have "emptied the tank".
"You can listen to something and know that it's your best.
"I mean I've put music out myself which I know wasn't finished and it's a horrible feeling.
"That will have to do, is never a phrase that will do it with music. Maybe with toast or lunch or something, but not with music".
The studio is filled with instruments, high-end sound and recording equipment, and an easy vibe smothers the room.
Australian-born kiwi artist Renee Milner says the space has a lot to do with how she feels about making the trek to Ōakura.
"It's a beautiful space to walk into, not just within the studio, but also the nature that you see outside".
She says Johnson has "an incredible knack of bringing out the best in the artist".
Mark Armstrong, the lead singer of The Slacks, says Johnson is special "because of his absolute love and passion for music".
"You can see when he is at his desk, when he's putting a mic on somebody when he's listening to a playback, he's actually just coming to life because that's what he loves.
"He tells us all the time it's just 'such a pleasure of my life to be able to make music with people who are passionate about music'."
Armstrong says Johnson has "a very unique process".
"I will come to him with a song and with the general structure and then we work together producing that track to work out what we think that track needs."
Johnson's partner normally has the final say on how well he has worked each day.
Saunders is a non-musician with a fresh pair of ears and a face full of expression - or not.
"I just look at their face and know it's been a whole day wasted."