GSCARTSW paired with Extron rxi is great--why?

[HDgaming42]

I posted some time ago about issues with using an extron RGB 203 rxi for centering controls.

I was surprised to learn that this unit is known for being picky, and not terribly successful with 15kHz signals, as it's always worked smashingly for me. Now I know why--the GSCARTSW v3.4 using the DE-15 connector.

I don't know what voodoo it's performing, but whatever it's doing it's great. All my consoles output CSYNC, and yet connecting them directly to the extron (via a female scart to DE-15 connector) results in no signal. Running them into the GSCARTSW and then out via SCART into the extron still yields no picture.

Yet connecting CSYNC consoles through the GSCARTSW and then out through the DE-15 into the Extron yeilds an immediate lock on to the signal. No combination of dip switches (sync stripper and hsync/csync) drops the image.
The only thing I can think of is that the Extron will only accept TTL level sync, which the GSCARTSW outputs via the DE-15.

Yet the internet seems to have it's share of people complaining that external sync solutions don't always work--especially for the genesis. People complain about the Sync Strike, and the Sync Slayer II not ironing out compatibility, even with the later supporting TTL.

I have a second "retro" corner now and would like the centering controls of the extron to function there, but I don't really want to have to spring for a second GSCARTSW just to make the extron play nice. I also don't want to throw money at solutions that don't work.

1. Is anyone using a SyncSlayer II or alternate TTL sync solution with multiple consoles (I mean to test varying output resolutions) into an RGB 203 rxi? Extron SC210 perhaps?

2. @superg Is there any secret sauce going on in the v3.4 (before your sync regeneration feature) that could account for this? Something that standalone sync converters/processors could emulate to get the same results?

[fernan1234]

I suspect that your problems were solved by removing SCART from the connection to the Extron interface. I've never had issues like this with an Extron 203 rxi and other RGB interfaces with 15khz signals of all kinds of off-spec refresh rates and sync type on my DE-15 setup.

Basically I'd bet that anything that lets you avoid SCART is likely to work.

[HDgaming42]

I suspect that your problems were solved by removing SCART from the connection to the Extron interface. I've never had issues like this with an Extron 203 rxi and other RGB interfaces with 15khz signals of all kinds of off-spec refresh rates and sync type on my DE-15 setup.

Basically I'd bet that anything that lets you avoid SCART is likely to work.

Are you referring to supplying 15kHz via DE-15 from a PC, or MiSTER perhaps? Or are your consoles wired for DE-15? (wish I'd done this from the onset--waaaay too far down the rabbit hole of custom cables to go back).

[fernan1234]

Yeah all my console cables are wired for DE-15 RGBS, and RGBHV from DC, MiSTer, Pi, HDMI+DAC have also been fine.

Maybe the problem lies on the SCART output of that older gscart switch though. I imagine that most other solutions you could replace in your chain would solve your issues.

[superg]

gscartsw v3.4 has 3 things which other switch versions don't:
1. EL1883 which is basically LM1881 plus additional vertical sync output which made VGA possible
2. Full DC restore circuit
3. TTL sync output
Based on your description, Extron rxi requires clean sync of a certain amplitude (TTL?).
VGA: CS/OFF toggle is inactive for VGA, it always gets clean sync (after EL1883 output). HV/CV toggle enables/disables HV sync on VGA so if it doesn't affect anything it means that extron accepts clean composite sync.
SCART: when CS is active, SCART sync line has the exact same sync as VGA so I don't see how that can't work with SCART to VGA rewire, bad adapter?

Newer switch versions don't have EL1883, sync regeneration is doing exactly the same but faster and sharing parts of the circuit for sync based signal detection. DC restore is not needed because improved design allows AC/DC coupled signal to pass through switch without changes (as is). And TTL amplitude sync was switched to 75ohm terminated so it's 1Vpp, that's why I think extron doesn't like newer gscartsw sync output. If I remember correctly, this can be changed easily by replacing some resistors but I won't be helping with that, sorry!

[HDgaming42]

gscartsw v3.4 has 3 things which other switch versions don't:
1. EL1883 which is basically LM1881 plus additional vertical sync output which made VGA possible
2. Full DC restore circuit
3. TTL sync output
Based on your description, Extron rxi requires clean sync of a certain amplitude (TTL?).

Yes,
Input level 2 V to 5.5 Vp-p with ±0.2 VDC offset max.
Output level TTL: 4V to 5V p-p, unterminated

VGA: CS/OFF toggle is inactive for VGA, it always gets clean sync (after EL1883 output). HV/CV toggle enables/disables HV sync on VGA so if it doesn't affect anything it means that extron accepts clean composite sync.
SCART: when CS is active, SCART sync line has the exact same sync as VGA so I don't see how that can't work with SCART to VGA rewire, bad adapter?

Newer switch versions don't have EL1883, sync regeneration is doing exactly the same but faster and sharing parts of the circuit for sync based signal detection. DC restore is not needed because improved design allows AC/DC coupled signal to pass through switch without changes (as is). And TTL amplitude sync was switched to 75ohm terminated so it's 1Vpp, that's why I think extron doesn't like newer gscartsw sync output. If I remember correctly, this can be changed easily by replacing some resistors but I won't be helping with that, sorry!

Thanks for the super informative post!

[Fatass]

Interesting. I used to have an extron RGB 201 rxi which is just a 1 input version of the 203 iirc and it never played nice with 15khz. Always either having a problem displaying 240p sources or having tearing at the top of the screen for 480i while adsp was turned on. Yeah, i mostly hooked it to consoles via scart (75ohm) which was being fed to a switcher, to a sync strike, to the extron then back out through a umsa to a scart tv. Perhaps a sync slayer 2 outputting ttl would have set things right but I've sold most of my extron stuff by now.

[Gara]

I'm one of the people who has had countless troubles with the Extron 203 rgb rxi. The top part of the image with 15khz sources would always look like this;
http://imgur.com/a/NTlMsYt
I tried multiple input chains and different dipp switches. I always had to use a Sync Strike or Sync Strike equivalent to get an image though. My normal chain was the following;
Gscartsw lite>scart splitter>sync strike>extron 203>extron sw2 rgbhv>extron ada 4 300mx>monitor

I recently changed around my setup and all of a sudden I am getting the results I always wanted. No more garbled image and full centering controls. What happened is that I decided to replace the RGB Scart splitter with an Extron RGBHV BNC splitter. Since I no longer needed the Sync Strike for Scart to DB15 I removed it from the chain.

Gscartsw lite>extron da2 rgbhv>extron 203>extron sw2 rgbhv>extron ada 4 300mx>monitor.

I'm not exactly sure what fixed it. It has been quite a while since I tested it, but I previously couldn't get an image going from Gscartsw Lite to Extron 203 using a Scart to DB15 cable. It produced an image with a LM1881 built into the cable, but it gave the same problems as the Sync Strike by warping the top of the image.

I guess the Extron DA2 RGBHV video distribution amplifier was the fix?

[superg]

I'm one of the people who has had countless troubles with the Extron 203 rgb rxi. The top part of the image with 15khz sources would always look like this;
http://imgur.com/a/NTlMsYt
I tried multiple input chains and different dipp switches. I always had to use a Sync Strike or Sync Strike equivalent to get an image though. My normal chain was the following;
Gscartsw lite>scart splitter>sync strike>extron 203>extron sw2 rgbhv>extron ada 4 300mx>monitor

I recently changed around my setup and all of a sudden I am getting the results I always wanted. No more garbled image and full centering controls. What happened is that I decided to replace the RGB Scart splitter with an Extron RGBHV BNC splitter. Since I no longer needed the Sync Strike for Scart to DB15 I removed it from the chain.

Gscartsw lite>extron da2 rgbhv>extron 203>extron sw2 rgbhv>extron ada 4 300mx>monitor.

I'm not exactly sure what fixed it. It has been quite a while since I tested it, but I previously couldn't get an image going from Gscartsw Lite to Extron 203 using a Scart to DB15 cable. It produced an image with a LM1881 built into the cable, but it gave the same problems as the Sync Strike by warping the top of the image.

I guess the Extron DA2 RGBHV video distribution amplifier was the fix?

I experienced exactly the same image warping when using Micomsoft Xsync-1 (splits signal to two destinations, VGA and RGBS at the same time). They use two sync stripper chips (LM1881 and something more advanced, forgot the name) and you could choose which one by the switch, I guess they didn't handle it right.

[Guspaz]

Surely there's some major signal degredation feeding analog signals through that many processing devices in a row?

[Gara]

Surely there's some major signal degredation feeding analog signals through that many processing devices in a row?

You'd think so. A tiny bit of brightness is lost, but I can't see any sharpness lose on my BVM D20 and other monitors. I looked for added noise and other imperfections, but if they are there I couldn't notice them after switching back and fourth for an embarrassing amount of time. I'm sure something is lost along the way, but I'm trying not to let it bug me if I can't notice it with my nose pressed against the screen.

I made sure my cables are all high quality and as short as possible. Retro Access coax on all my consoles. Most of the Extron gear is stacked and all wired with 1ft Canare LV-61S BNC cables. I was using Rg59 jumper cables, but they were so rigid they would lift the Extron boxes.

There are days I'd wish I'd gone the Extron Crosspoint route, but I do so love chained together Gscartsw units and auto switching. It took a few years to become the convoluted mess it is now.

[kitty666cats]

@Gara, your issue in those images looks to be probably serration pulse and/or vsync pulse width - the Extron 580xi has dipswitches on the front for it, but other interfaces (like my 164xi) have jumpers inside that can be adjusted - check the manual for your unit.