Hercules-EBX CPU User Manual V1.02
Page 20
Signal Name
Definition
Headphone / Line Out Line Level output, capable of driving headphones
Referred to as “Headphone Out” in most sound documentation
Line Input
Line-Level input; referred to as “Line In” in most sound documentation
Auxiliary Input
Line-Level input; referred to as “AUX In” in most sound documentation
Microphone Input
Microphone-level mono input; phantom power provided via pin 9
The sound chip used is AC97-compatible. The “Line Out” is powered and used for the amplified
speaker output (See J13 below). The line-level output listed above is listed as either “Headphone
Out” or “Line Out 2” in most of the software and documentation for this sound interface.
Connector Part Numbers
J12 Connector on CPU board:
Digi-Key Corp. A1925
J12 Mating Cable Connector:
Molex
22-01-3107
4.9 Speaker Connector – J13
1
Speaker LEFT High (+)
2
Volume – LOW
3
Speaker LEFT Low (-)
4
Volume – MID
5
Line-level Mono Output
6
Audio Ground
7
Speaker RIGHT Low (-)
8
Volume – HIGH
9
Speaker RIGHT High (+)
10
No-Connect
Table 9: J13 – Amplified Speaker Connector Pinout
Signal Name
Definition
Speaker LEFT +/-
Speaker Connection Pair for LEFT speaker (4 Ohm Speaker)
Speaker RIGHT +/-
Speaker Connection Pair for RIGHT speaker (4 Ohm Speaker)
Mono Output
Line-Level mono output (for reference)
Volume – LOW, MID, HIGH These are volume controls for the attached speakers.
NOTES:
•
Volume Control: The volume control is capable of 32 discrete levels, ranging from a 20dB
maximum gain down to -85dB (Muted). The main volume control is the “MID” line: this may
be tied to the center tap of a potentiometer with “HIGH” on one side and “LOW” on the other
to give a full range of power control.
o
Shorting “MID” to “LOW” will mute the speaker audio.
o
Shorting “MID” to “HIGH” will provide maximum gain.
o
Default (with no connection) provides 10dB of gain.
•
Maximum Output Power: The maximum output power is specified to provide up to 2 Watts
into a 4 Ohm speaker load. Note that this output power is drawn from the on-board 5V
supply.
