The KS-16611-L1's have 3 primary taps for use with mic or line inputs. The available ratios are 1:13, 1:26 and 1:52. The "gain" switch on this box can be wired for any 2 of these 3 ratios. By default it will be sent with 1:13 on "lo" and 1:26 on "hi", which are the most useful for the widest variety of low output cartridges, but just let me know if you need the 1:52 tap for a very low output cart.
The ground switch can connect the box to the left or both audio channel shields, or in the middle position the box can be left floating so you can run a separate wire to your preamp's ground post without creating a ground loop. This allows you to use a variety of wiring schemes and cables with the box. For the most part you can just hook up the box in the most convenient way and put the ground switch in whatever position gives the lowest noise.
This box is priced a little higher than the other empty transformers boxes I sell because of the difficulty and expense of finding good quality 9 pin sockets. For a long time now I've only used NOS sockets, but am now down to my very small supply of good used ones. I don't know if I'll be able to continue selling these 9 pin bases for too much longer! The sockets are carefully cleaned and tensioned before hookup, and the box is tested and guaranteed to work provided your transformers also work. Please let me know if you have any questions. Thanks!