3. I/O Header and Jack Pinouts
In the header pinouts described below, note that the audio speaker amplifier outputs appear on three headers: J3, J4, and J5. Also note that Line In has two connection points (J4 and J6) and Line Out has two connection points (J4 and J5).
Configuration information for all headers is shown on pages
Caution: Only one Speaker connection may be used at one time. If more than one connection is used, the load impedance on the audio amplifier will be too low, and the audio amplifier could be damaged.
Caution: Only one Line In connection may be used at one time. If more than one connection is used, the line impedance will be too low. This could cause distortion or other malfunction.
Caution: Only one Line Out connection may be used at one time. If more than one connection is used, the line impedance will be too low. This could cause distortion or other malfunction.
J3: Speaker connections with optional volume control,
Volume Left Out | 1 | 2 | Volume Left In (Wipe) |
Analog Ground | 3 | 4 | Volume Right Out |
Volume Right In (Wipe) | 5 | 6 | Analog Ground |
Speaker Out Left + | 7 | 8 | Analog Ground (Speaker Out L |
Speaker Out Right + | 9 | 10 | Analog Ground (Speaker Out R |
This header enables the user to control volume with an external stereo 100KΩ potentiometer. The output volume on each channel is directly proportional to the resistance between the wiper for that channel and ground.
J4: Main I/O header, 2x10-pin right-angle header
Speaker Out L + | 1 | 2 |
| Analog Ground (Speaker Out L |
Speaker Out R + | 3 | 4 |
| Analog Ground (Speaker Out R |
CD In L | 5 | 6 |
| CD In R |
Mic In + | 7 | 8 |
| Analog Ground (Mic in |
Line In L + | 9 | 10 |
| Aux In L |
Line In R + | 11 | 12 |
| Aux In R |
Line Out L + | 13 | 14 |
| Analog Ground (Line Out L |
Line Out R + | 15 | 16 |
| Analog Ground (Line Out R |
Digital Ground | 17 | 18 |
| Mute Input |
Volume Up Input | 19 | 20 |
| Volume Down Input |
This header provides connections to all the most commonly used I/O signals on
P. 5 |
