When you look at the
back
of a midi socket, you will see six terminals. If you are lucky then
they will be labelled, but quite often they are not. We will firstly consider the five of them that
form a half circle. If you position the socket so that the middle terminal is at the top, then the
pin numbers go 3, 5, 2, 4, 1. Pin 2 is therefore at the top. The sixth terminal is normally
opposite to pin 2 and connects to the metal surrounding of the socket. We shall call this pin
the 'sleeve' pin.
x 2
x 5
x 4
x 3
x 1
x Sleeve
The midi sockets are wired up as follows:
MIDI_IN
Pin 1 on PCB goes to Pin 4 on socket
Pin 2 on PCB goes to Pin 5 on socket
MIDI_OUT
Pin 1 on PCB goes to Pin 4 on socket
Pin 2 on PCB goes to Pin 2 on socket
Pin 3 on PCB goes to Pin 5 on socket
If you have used a plastic audio output socket then you should also connect pin 2 on the midi
output socket to the sleeve solder tag. This can normally be done with a small length of solid
core wire on the socket itself. By making this connection you will have connected the metal
case to 0V (ground) and screened your case.
If you have used plastic midi sockets, or have metal ones with no sleeve connection, as well as
a plastic output socket you should still ground your case. Drill a 3mm hole into your metal
case at the rear. Fit an M3 screw through this hole and with a nut, toothed washer and solder
tag create a grounding point on the inside of your case. Then connect a wire from this
grounding point to the GND pad on the TM3030 PCB.
That completes the wiring of the TM3030.
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