Air Tight ATC-1 preamp question

How many of the 5 tubes in this pream are used for the line stage?
Thank you
The two tubes inside the chassis are used for the linestage. There are three tubes on the left side of the chassis that are installed horizontally in a recessed area and these are for the phono stage. Great preamp by the way, I used to own one and I regret selling it even now. Happy listening!