Instructions for SCART2ARC30

RGB and audio amplifier board for arcade interface applications.

Audio Section

J9 is the stereo speaker output terminal - it's always enabled. Speakers can be wired directly here directly or connected via J8.

J8 is a 5 pin header (JST VH) which is the power input and JAMMA/Neo Geo speaker output connector.

J8 pin list:
 1. Resistor load for 5v supply
 2. 12V power input for audio amp
 3. Ground
 4. Speaker+ (Neo Geo right)
 5. Speaker- (Neo Geo left)

Pin 1 of J8 is not connected to the 5V video amp power.

Pin jumpers JP1 and JP2 set the speaker output configuration for J8. The two jumpers must be set identically. There are three valid positions.

1-2. Stereo Neo Geo configuration (also set SW2 off)
2-3. Speaker+ and Speaker- disconnected
3-4. JAMMA mono configuration (also set SW2 on)

J6 3.5mm socket carries the line level audio signal from the SCART socket. If the arcade machine already has an audio amplifier you want to use instead, connect its input here.

J4 3.5mm socket is an audio input. Connecting a cable will disconnect audio from the SCART source.

SW2 is a mono mixing switch. In the on position it will mix the two stereo channels into a single mono channel. Recommended for the JAMMA mono configuration.

RGB Video Section

J1 is a SCART socket for RGB video and audio input. This board supports RGB video only - there is no decoder for composite video, s-video, component video.

J2 is a 7 pin header (Molex KK254) which carries the video output header.

J2 pin list:
 1. Ground
 2. 5V power input for video amp
 3. Ground
 4. Blue out
 5. Green out
 6. Red out
 7. Composite sync out

J3 is a separate power input provided for convenience.

SW1 enables the sync protection feature in the on position. This will stop the sync output if the frequency gets significantly higher than the standard 15.7 kHz.

Last updated 5/6/2020.