1000 Circuit Points must be used to create a 1 Volt socket, which Tubes can then be inserted into. The sockets can be upgraded to take more volts, requiring 500 + (500 * voltage) Circuit Points to upgrade. All sockets must be next to each other in the grid, or some sockets will not count as part of the Circuit. Sockets can also be downgraded 1 volt, for a 50% refund to the Circuit Points. Even if the grid has 44 total holes, the system allows to put at most 30 sockets, and they all have to be connected with each other (it's not possible to have 2 or more separated groups of sockets).