Bill and Will's Synth Construction
Switchcraft Jacks

Synthesis Technologies uses the enclosed type of jacks.

Here's a chart of the Switchcraft Jack Types:

Jack Type 1 - (Switchcraft part # 111X)

When no plug is inserted, no contacts are made.

When a plug is inserted, the shank contacts the low point - the tip contacts the upper point.

Jack Type 2 (Switchcraft part # 112AX)

When no plug is inserted, the middle point connects to the upper point - so a circuit between the upper and middle points is closed.

When a plug is inserted, this circuit is broken and the jack shank contacts the lower point, the jack tip contacts the upper point.

Jack Type 3 (Only available in unclosed jack type - Switchcraft part # 13A)

When no plug is inserted, the lower-middle, upper-middle, and upper-points all connect - several possible circuits are possible.

When a plug is inserted, any circuit involving the lower-middle point is broken while the connection remains between the upper and upper-middle points - the jack shank contacts the low point - the tip contacts the upper-middle point.

Jack Type 4 (Only available in unclosed jack type - Switchcraft part # 13E)

When no plug is inserted, the upper and upper-middle points connect - so this circuit is closed.

When a plug is inserted, this circuit is broken and the jack shank contacts the low point and the tip contacts the lower-middle point.

Jack Type 5 (Switchcraft part # 112BX)

When no plug is inserted, no points are connected.

When a TRS plug is inserted, the jack shank contacts the low point, the ring contacts the upper point, and the tip contacts the middle point.

Jack Type 6 (Switchcraft part # 113BX)

When no plug is inserted, the upper-middle and lower-middle points are connected creating a closed circuit.

When a TRS plug is inserted, this circuit is broken and the jack shank contacts the low point, the ring contacts the upper point, and the tip contacts the upper-middle point.

Jack Type 7 (Switchcraft part # 114BX)

When no plug is inserted, the upper and upper-middle points are connected and the middle and lower-middle points are connected.

When a TRS plug is inserted, these circuits are broken and the jack shank contacts the low point, the ring contacts the upper point, and the tip contacts the middle point.

Jack Type 8 (Switchcraft part # 113FX)

When no plug is inserted, the upper-middle and lower-middle points are connected.

When a TRS plug is inserted, this circuit is broken and the jack shank contacts the low point, the ring contacts the lower-middle point, and the tip contacts the upper point.

This jack is unique in that it's the ring contact that gets switched rather than jack #6 where it's the tip.

Jack Type 9 (Switchcraft part # 113X)

When no plug is inserted, no contact is made.

When a plug is inserted, the jack shank contacts the low point, the tip contacts the lower-middle point, and the circuit is closed between the upper-middle and the upper point.