Extron Crosspoint TTL Output Conversion

[FinalBaton]

Just wanting to make sure : is TTL fine on pro CRTs?

Wouldn't risk damaging the NEC XM37 Plus
Can I safely guess that it accepts TTL and at voltages that are fine with an Extron System 8 Plus?
(I know it says TTL below, but I just want to make 100% sure that the voltages are compatible, since I don,t understand all that voltage stuff)

[Guspaz]

Check the spec sheet, it should list the voltage ranges expected for sync.

[FinalBaton]

image I posted in my previous post is of the monitor's specs.

Now here's all I could find regarding the Extron.
It does say that the sync is 510ohm output. but it doesn't mention any voltages...

[Guspaz]

Sorry, imgur is blocked here, so I didn't realize there was an image. I meant the spec sheet for the monitor:

https://www.manualslib.com/manual/10986 ... =29#manual

It says it requires TTL csync. I think that's common on any PC monitor, because VGA normally uses TTL separate sync.

[FinalBaton]

cool. Now, does the Extron output TTL sync?

It doesn't mention any voltages but it says 510ohm on the spec sheet

[Guspaz]

Doesn't cr4zymanz0r's post on the first page list all that? I looked up a random Crosspoint RGB on Extron's site (the Crosspoint Ultra 1212), and it listed all the voltages and such (they're very similar), including listing TTL sync.

[FinalBaton]

My unit is not a Crosspoint. It's an earlier Extron machine called "System 8 Plus". That's why I was asking

[Guspaz]

https://www.extron.com/download/files/s ... 102006.pdf

Output level.................................. 0.5 V to 5 Vp-p, unterminated

[FinalBaton]

Woah. Didn't find that document. This info was not in the user manual

Thanks!

[Carpetman]

Here is a link to an article testing the outputs of a couple of Crosspoints with and without ADSP on an oscilloscope, if anyone wants to check it out.

https://www.snailtoothgaming.com/articl ... nc-output/

[Dochartaigh]

Here is a link to an article testing the outputs of a couple of Crosspoints with and without ADSP on an oscilloscope, if anyone wants to check it out.

https://www.snailtoothgaming.com/articl ... nc-output/

I read that (and didn't understand much of it). I'm trying to find out if my Extron Crosspoint with ADSP is safe to use with a Framemeister or if I should add the 470 Ω resistor (or not).

[Carpetman]

Here is a link to an article testing the outputs of a couple of Crosspoints with and without ADSP on an oscilloscope, if anyone wants to check it out.

https://www.snailtoothgaming.com/articl ... nc-output/

I read that (and didn't understand much of it). I'm trying to find out if my Extron Crosspoint with ADSP is safe to use with a Framemeister or if I should add the 470 Ω resistor (or not).

According to this article, whether it has ADSP or not, it still amplifies the sync to ttl. You should put the 470 ohm resistor on the sync output to the Framemeister either way.

[strygo]

That blog post was a good read. It led me to research a few of the devices in my chain.

Extron MVX 88 VGA
This device seems functionally equivalent to the Crosspoint and accepts both voltage levels but outputs the higher voltage level for sync.

Extron RGB 201-203 Rxi, 580xi
It looks like the RGB Rxi units exhibit a similar behavior and accept both voltage levels but output the higher voltage for sync.

Mimo Genius II
According to its documentation, it seems like you need to be mindful of which input you use. The 15 pin dsub input expects a lower voltage level, but the 6 pin amp modu-1 connector can accept the higher voltage.

Lumagen VisionHDQ
Its documentation seems to imply it only accepts lower voltage sync levels. "Absolute maximum rating is +/- 2 volts, referenced to case ground, for analog video inputs."

I am a bit confused why a VGA switch would output this higher voltage level. Does anyone know why this would be the case?

[lechu]

Okay, I want to make sure I have this straight. There seems to be some confusion in a bunch of sources I'm seeing.

I have an Extron Crosspoint. I have seven RGB consoles (5 csync, 2 luma with sync strippers), one VGA, and two component. I have outputs going to my OSSC and Ikegami TM14-17R.

For the Component consoles, don't worry about it because they don't use the Sync lines.

For the VGA, the OSSC can handle the higher voltage through the VGA port, so no need to worry there (not 100% on this one).

For the RGB consoles, if I'm able to turn the 75 ohm on, do it or else the OSSC will be in emotional pain. If I don't have the 75 ohm option on the switcher itself, put a 470 ohm resistor on the Sync Output lines.

So, for the OSSC, could I just put a 470 ohm resistor in the scart head on pin 19 in the OSSC and be done with it? Or is there something I'm missing?

[jayde6]

For the VGA, the OSSC can handle the higher voltage through the VGA port, so no need to worry there (not 100% on this one).

For the RGB consoles, if I'm able to turn the 75 ohm on, do it or else the OSSC will be in emotional pain. If I don't have the 75 ohm option on the switcher itself, put a 470 ohm resistor on the Sync Output lines.

So, for the OSSC, could I just put a 470 ohm resistor in the scart head on pin 19 in the OSSC and be done with it? Or is there something I'm missing?

I recall reading the same thing about the vga port on the OSSC but would check again on the videogameperfection forums if it was me.

Those 75ohm dip switches do not affect the output voltage level, they are strictly to shape the input. So you will need to put the resistors on the sync lines going to the ossc, the TM14 should be able to handle it fine without but I'd check the manual for it. Everything else seems correct.

[lechu]

For the VGA, the OSSC can handle the higher voltage through the VGA port, so no need to worry there (not 100% on this one).

For the RGB consoles, if I'm able to turn the 75 ohm on, do it or else the OSSC will be in emotional pain. If I don't have the 75 ohm option on the switcher itself, put a 470 ohm resistor on the Sync Output lines.

So, for the OSSC, could I just put a 470 ohm resistor in the scart head on pin 19 in the OSSC and be done with it? Or is there something I'm missing?

I recall reading the same thing about the vga port on the OSSC but would check again on the videogameperfection forums if it was me.

Those 75ohm dip switches do not affect the output voltage level, they are strictly to shape the input. So you will need to put the resistors on the sync lines going to the ossc, the TM14 should be able to handle it fine without but I'd check the manual for it. Everything else seems correct.

This stuff goes over my head a little bit. For the Ikegami, I found this information:

Video Signal:
Composite 1.0 Vp-p
Non Composite 0.7 Vp-p

Y/C signal:
Y signal 1.0Vp-p
C signal 0.286Vp-p (burst level)

RGB or Y, Pb, Pr:
(RGB Signal)
G signal 1.0Vp-p (Sync on Green) or 0.7Vp-p
R/B signal 0.7Vp-p
(Y, Pb, Pr signal) N10/SMPTE Format
Y White: 0.7Vp-p
Setup: 0%
Sync: 0.3Vp-p
Pb, Pr: 0.525Vp-p

Digital Video (D1, D2, D3):
Serial: 0.8Vp-p ± 10%

Sync Signal: Composite Sync 4Vp-p ± 2Vp-p

I think that last line is the important one. I think that means the Crosspoint as it is will be fine for this TV. Again, whoosh.

[jayde6]

This stuff goes over my head a little bit.

I was in the same boat not too long ago, it's a lot to take in and I'm still learning. There is so much I don't know as well. That's why I usually say to double check the info in my replies or wait for others to chime in as well, just in case I picked up some bad info along the way.

Sync Signal: Composite Sync 4Vp-p ± 2Vp-p

The article linked above measured the voltage from the sync output of the extrons at 2.4vp-p. So if that's the info about the input you're going to use on the Ikegami then it would be fine because of that ± 2Vp-p, basically says it can handle anything from 2 to 6Vp-p.

[SamIAm]

I just verified with my own oscilloscope that the C-sync output of my Extron RGB 202 Plus (an old model) is ~2.4V p-p.

However, that blog didn't seem to take into account what happens when you terminate the signal with 75 ohms. I just checked, and the waveform is roughly 1.4V p-p in that case.

It's still too much for receivers that want only 1V p-p max, but anyway, this is hopefully good to know for someone.

[Woozle]

I just spliced together a BNC to scart cable for my 8x8 extron CC -> OSSC and put a 470ohm resistor on the sync line. I didn't actually measure anything yet (bad practice, I know ). At this point I just wanted to drop the voltage, I figured the sync from the CC is likely anywhere from 2v-5v so worst thing that a 470ohm resistor would do is drop the voltage too low for the OSSC. Seems to work fine with the OSSC so far, but eventually I'll get around to measuring it on my oscilloscope to make sure everything is ok.

[strygo]

I got confirmation from Mimo that the Genius II accepts TTL sync across all inputs, so it is fully compatible with the CrossPoint/MVX units.

[Dochartaigh]

I'm about ready to start experimenting with my OSSC and XRGB-mini and wanted to get some solution in place to lower the sync to an acceptable level. Would I be able to use a simple BNC attenuator like this on the Sync line and call it a day?

A member on the CRT Gaming subreddit said:

The dB attenuation is relative to a 50ohm terminated input and output, while you're working with a lower impdance source and 75 ohm output. Assuming they're using a pi resistor network and the output of your sync source has zero impedance, a 20dB nominal attenuator should drop 5V down to about 0.6V at the receiving end, which is what you want.

...so I just wanted to see if something like this would work as an out-of-the-box solution, no ripping open SCART heads, or BNC wires and soldering on resistors would be great...



Related question: do I have to worry about all this too-high TTL sync on things like Component? No, correct, since there's no separate sync line? I output YPbPr out of my Extron Crosspoint Ultra HVA 128 straight to my Sony consumer TV's, and to my OSSC/XRGB as well...

[orange808]

Related question: do I have to worry about all this too-high TTL sync on things like Component? No, correct, since there's no separate sync line? I output YPbPr out of my Extron Crosspoint Ultra HVA 128 straight to my Sony consumer TV's, and to my OSSC/XRGB as well...

Someone needs to put that on a scope.

The rumor is that ADSP is only performed on the dedicated sync lines. I am not so sure.

My experience with Extron RGB units suggests that Extron units do sometimes perform sync processing on the RGB lines. Passing 480i component through and tricking a CRT into displaying 240p is proof of that.

The ADSP on the Crosspoint is different, but I find hard to believe Extron would only support RGBHV, and RGBs--while ignoring Sync on Green and component. In theory, only SoG would get ADSP, but there's no telling what the Crosspoint does.

[Guspaz]

Component doesn't have a separate sync signal so it's not a concern. The OSSC can handle TTL sync on RGBS via the VGA input, although you lose most of the LPF control and 480i may have some issues.

[orange808]

Component doesn't have a separate sync signal so it's not a concern. The OSSC can handle TTL sync on RGBS via the VGA input, although you lose most of the LPF control and 480i may have some issues.

Good to know about the crosspoint and component video.

I have one laying around from a lot somewhere. Sounds like I should retire the Shinybow and try it out.

[RGB0b]

I'm about ready to start experimenting with my OSSC and XRGB-mini and wanted to get some solution in place to lower the sync to an acceptable level. Would I be able to use a simple BNC attenuator like this on the Sync line and call it a day?

Just get one of these and select 75ohm from the drop-down: https://www.retrogamingcables.co.uk/aud ... rter-cable

[Tapeworm]

Would I need to adjust output if outputting to a ShinyBow SB-2840 Scart to Component Transcoder?

[Dochartaigh]

I'm about ready to start experimenting with my OSSC and XRGB-mini and wanted to get some solution in place to lower the sync to an acceptable level. Would I be able to use a simple BNC attenuator like this on the Sync line and call it a day?

Just get one of these and select 75ohm from the drop-down: https://www.retrogamingcables.co.uk/aud ... rter-cable

Unfortunately buying another 10 or so breakout cables to replace what I'm already using isn't realistic I'm sorry to say.

What about those BNC attenuators I linked to above? If those, from a technical standpoint (far above my paygrade lol would work on the Extron Crosspoint on the output sync line...that would be a SUPER easy, non-solder solution which EVERYBODY using an Extron Crosspoint would love to have. Simply put it on the sync line for those sensitive devices which need 75 ohm and you would be set. No soldering, no opening SCART heads, no reading pinouts (which is more than many of us know how to do). Literally plug and play. Anybody have any comments on those?

Would I need to adjust output if outputting to a ShinyBow SB-2840 Scart to Component Transcoder?

I have an email out to them - they wrote me back saying if my equipment is outputting "4.0 to 5.0 Vp-p" that "there is something wrong with it", so the person I'm talking to doesn't seem to be familiar with pro-quality (and in wide use back in the day) switchers like the Extron. I wrote him back with a link to the Snailtooth article and am waiting to hear back from them.

[RGB0b]

Unfortunately buying another 10 or so breakout cables to replace what I'm already using isn't realistic I'm sorry to say.
What about those BNC attenuators I linked to above?

You're using 10 outputs???

If not, you don't need to worry about any of the inputs, just the cable outputting from the Crosspoint to the OSSC, Framemeister, or any device with a SCART input (like the SCART to component converters). If you don't want to buy a new cable, you could just add a resistor to the sync line of the output cable. Most likely 470ohm will be fine, but confirming with a scope would be the safest bet. I don't think those BNC things you liked to have enough resistance and are meant for something totally different.

[Wolf_]

Just a heads up for anyone asking:
1) The sync attenuation switches on the back don't change the output and never need to be adjusted.
2) 510 ttl is too high for the ossc scart input but works perfectly fine with a bnc to vga cable for the vga input of the ossc.
3) The sync boost happens on the 4th input so the top 3 for rgb won't impact component video.
4) For the record rgb scart csync over bnc to 510 ttl sync out from bnc to vga is a lagless direct conversion.
Source: https://www.snailtoothgaming.com/articl ... nc-output/

[Dochartaigh]

You're using 10 outputs???

I'm actually using 13 outputs right now (8 monitors, 3 converters which I loop back into the Extron Crosspoint Ultra 1616 HVA, OSSC/XRGB-mini, 1 test output line, and plans to use ~2 more for some other converters), but not all use BNC to SCART cables like you linked to. Right now I would need 4 of those: OSSC, XRGB-mini, ShinyBow SB-2840, and need one for the test line as well.

I will probably just open up the SCART head and put in a 470 ohm resistor - I believe that's on pin #19??? on these BNC to SCART cables running off the output side of the Extron.

Would I need to adjust output if outputting to a ShinyBow SB-2840 Scart to Component Transcoder?

Shinybow confirmed their unit is only safe with 1 Vp-p so we would need a resistor on the sync line coming off the Extron to make it safe for the SB-2840.