Most Tri-Sync monitors switch automatically between 31kHz, 24kHz and 15kHz video, unfortunately they cannot switch automatically between Jamma level RGB (high-impedance), and VGA level RGB (low-impedance). The solution provided by the manufacturers is either
- Dedicated connector for high-impedance video (most common)
- High/Low impedance switch (pretty rare)
Some tri-sync monitors also have issues with the composite sync signals from some games, most notably Taito F3.
Tri-Sync Helper rev 2.0
To make this a little easier, you can order this add-on board that plugs directly into the Jammafier. It performs two functions:
- RGB attenuation and re-amplification
- Sync separation and re-generation
- Selectable output with either regenerated CSYNC or H/V sync
It transforms the video from high to low impedance, and also cleans and separates the sync from Jamma into horizontal and vertical sync. This way you will only need one video cable, and no switches to worry about. It should also take care of most sync problems. It is important to note that it does not change the scan rate - you will need a scaler if your monitor does not support 15kHz Jamma video.
Do I want a Tri-Sync Helper checklist?
- I'm using the Retro Scaler A1
- No, you do not need a helper, the A1 can process raw jamma video signals.
- But using a Tri-Sync Helper will make the A1 better?
- No, it will not
- I'm using the Jammafier with a Tri-Sync monitor
- Yes, a helper will make your life easier
- I want to use the OSSC with the Jammafier
- Yes, you need the helper to attenuate RGB. The sync processing of the helper will also assist the OSSC and make it less painful to use with arcade boards.
- I have a Vewlix cabinet..
- A vewlix LCD requires a scaler, if you use the A1 you do not need a helper. If you use the OSSC, you need a helper.
Powering the Tri-Sync Helper
The Tri-Sync Helper is powered via pin 9 on it's input connector. The Jammafier can will supply this.
Jammafier rev 1.7
Jammafiers are shipped with the switch in the off position, change it to the 5V position to supply power to the helper.
Jammafier earlier revisions
Close this solder jumper with a blob of solder to enable 5V via VGA.