How to Determine TTL Sync

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Tempest_2084
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How to Determine TTL Sync

Post by Tempest_2084 »

After reading the warning about not using TTL Sync SCART cables with the 5X Pro, I got to wondering if any of my cables are using TTL Sync. Unfortunately I got my cables from a variety of places over the years so I can't even begin to tell who made them and how they might have been wired up. Is there an easy way to determine if a SCART cable is using TTL Sync? I have cables for these consoles:

NES
SNES
N64
PS1
PS2
Genesis 2
Saturn
DC
TurboDuo
XBox

I have my SCART cables going into an Otaku SCART switch which then goes to a Shinybow to convert it to Component. I'm not sure if there's a way to determine if they're using TTL sync with this setup or not. I know the Shinybow will accept TTL, but I'm not sure about Otaku switch.
mikechi2
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Re: How to Determine TTL Sync

Post by mikechi2 »

If you got everything routed to that Shinybow, just use the component video port and you're all set.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

mikechi2 wrote:If you got everything routed to that Shinybow, just use the component video port and you're all set.
I could I suppose, but wouldn't the SCART on the 5X Pro look better as it's not going through two devices? The Shinybow is ok, but it's not the greatest.
mikechi2
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Re: How to Determine TTL Sync

Post by mikechi2 »

Tempest_2084 wrote:
mikechi2 wrote:If you got everything routed to that Shinybow, just use the component video port and you're all set.
I could I suppose, but wouldn't the SCART on the 5X Pro look better as it's not going through two devices? The Shinybow is ok, but it's not the greatest.
Just try both and see. I doubt there's a huge difference for standard def signals. Xbox and PS2, I would try to use their native component output if possible since that will be highest quality.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

mikechi2 wrote:
Tempest_2084 wrote:
mikechi2 wrote:If you got everything routed to that Shinybow, just use the component video port and you're all set.
I could I suppose, but wouldn't the SCART on the 5X Pro look better as it's not going through two devices? The Shinybow is ok, but it's not the greatest.
Just try both and see. I doubt there's a huge difference for standard def signals. Xbox and PS2, I would try to use their native component output if possible since that will be highest quality.
My fear is blowing up my nice new 5X Pro. If it was just that TTL Sync didn't work that would be one thing, but I don't want to try a cable and damage the 5X. Your warning has put the fear of god into me. :)
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matt
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Re: How to Determine TTL Sync

Post by matt »

You can check the sync pin (pin 20 on a scart cable) with a volt meter. It's not an accurate way of determining the exact signal level, but it's good enough to tell the difference between TTL and 75 ohm sync.
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TooBeaucoup
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Re: How to Determine TTL Sync

Post by TooBeaucoup »

matt wrote:You can check the sync pin (pin 20 on a scart cable) with a volt meter. It's not an accurate way of determining the exact signal level, but it's good enough to tell the difference between TTL and 75 ohm sync.
What's the process for doing that exactly? Do you have to power on your console and measure the pin? And what levels are you looking for? Just curious.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

TooBeaucoup wrote:
matt wrote:You can check the sync pin (pin 20 on a scart cable) with a volt meter. It's not an accurate way of determining the exact signal level, but it's good enough to tell the difference between TTL and 75 ohm sync.
What's the process for doing that exactly? Do you have to power on your console and measure the pin? And what levels are you looking for? Just curious.
I think so. A friend of mine mentioned doing the same thing. He said turn the console on and use a multimeter to measure the voltage on the Sync Pin. He said if it goes over 1V at any time then it's most likely TTL.

What I don't know is if it has to plugged into a TV at the time (he said to display a bright image). If so, then I don't know how you'd be able to get a probe on the pin.
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Josh128
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Re: How to Determine TTL Sync

Post by Josh128 »

^^

For accuracy, the sync voltage should be measured in circuit, preferably with a full white screen. Measuring the pin not connected (zero loading) will give higher results and its possible you will see over 1V even on 75 ohm impedance sources.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

Josh128 wrote:^^

For accuracy, the sync voltage should be measured in circuit, preferably with a full white screen. Measuring the pin not connected (zero loading) will give higher results and its possible you will see over 1V even on 75 ohm impedance sources.
Not sure how to do that then. Any ideas?
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Josh128
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Re: How to Determine TTL Sync

Post by Josh128 »

Probe the video and sync pin to ground voltage on an opened up SCART connector while running the 240p suite on a full IRE white screen.
mikechi2
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Re: How to Determine TTL Sync

Post by mikechi2 »

Tempest_2084 wrote: My fear is blowing up my nice new 5X Pro. If it was just that TTL Sync didn't work that would be one thing, but I don't want to try a cable and damage the 5X. Your warning has put the fear of god into me. :)
Haha, I apologize for that. I mean one or two off uses won't do any damage. It'll take a long time. More concerned about the use of poorly implemented sync strippers causing compatibility problems. Best to ask your cable maker how the cable was setup. Regardless, my suggestion is to just run everything through the Shinybow. I really really doubt there will be any difference.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

mikechi2 wrote: Haha, I apologize for that. I mean one or two off uses won't do any damage. It'll take a long time.
Ok that makes me feel a little better. Can you tell right away that it's using TTL? Will the picture be all screwy or will it appear normal?
mikechi2
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Re: How to Determine TTL Sync

Post by mikechi2 »

Tempest_2084 wrote:
mikechi2 wrote: Haha, I apologize for that. I mean one or two off uses won't do any damage. It'll take a long time.
Ok that makes me feel a little better. Can you tell right away that it's using TTL? Will the picture be all screwy or will it appear normal?
Unknown, I give it 80% works perfectly, 20% it'll mess up the sync processor (as in image problem not immediate damage).
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

mikechi2 wrote: Best to ask your cable maker how the cable was setup. Regardless, my suggestion is to just run everything through the Shinybow. I really really doubt there will be any difference.
My problem is my cables are from all over the place. Ebay, custom made (like the one for my TurboDuo), some from major companies, but I'll be darned if I remember where they came from. I guess I'll have to use the Shinybow just in case, either that or buy all new cables. I'll have to use a switch box though as I was planning on running my GC through the component input as well (I'm curious as to how it makes the GB Player look).

At least this is a chance to weed out any crap cables I have since I imagine they'll look terrible on the 5X Pro when scaled up to 1080p.
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TooBeaucoup
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Re: How to Determine TTL Sync

Post by TooBeaucoup »

So as someone who knows quite a bit about mods and cables, but is certainly no expert. What about TTL Sync damages the 5X and why? I know it's obviously designed vastly different than the Framemeister and OSSC, but does TTL sync also damage those devices over time? Does that sync pump voltage into these devices? Sync is basically the one area that I've never understood all the ins and outs of.
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Guspaz
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Re: How to Determine TTL Sync

Post by Guspaz »

If I'm remembering correctly:

SoG: 0.7 volts
component/luma sync: 0.7 volts
cvbs sync: 1.0 volts
TTL sync: 5.0 volts

But then I also see this:

https://www.maximintegrated.com/en/desi ... /1184.html

That indicates that they're all 0.286 volts (with TTL still at 5)?
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maxtherabbit
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Re: How to Determine TTL Sync

Post by maxtherabbit »

Guspaz wrote:If I'm remembering correctly:

SoG: 0.7 volts
component/luma sync: 0.7 volts
cvbs sync: 1.0 volts
TTL sync: 5.0 volts
All of the sync-on-video (luma/CVBS/SoG) types are 1Vpp. 700mVpp for the active video and 300mVpp for the sync tip

TTL is usually 5Vpp but sometimes 3.3Vpp
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TooBeaucoup
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Re: How to Determine TTL Sync

Post by TooBeaucoup »

Guspaz wrote:If I'm remembering correctly:

SoG: 0.7 volts
component/luma sync: 0.7 volts
cvbs sync: 1.0 volts
TTL sync: 5.0 volts

But then I also see this:

https://www.maximintegrated.com/en/desi ... /1184.html

That indicates that they're all 0.286 volts (with TTL still at 5)?
So if I have SCART cables that all primarily use luma for sync, I should be ok with the Retrotink 5X?
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Guspaz
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Re: How to Determine TTL Sync

Post by Guspaz »

I don't want to speak authoritatively on Mike's behalf, but sync-on-luma ought to equivalent to cvbs sync from a compatibility standpoint.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

I wonder how common TTL sync cables actually are? Are they even worth worrying about?
fernan1234
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Re: How to Determine TTL Sync

Post by fernan1234 »

I can only think of some arcade board and Neo Geo MVS stuff really, but by this point most people using those already know the deal.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

fernan1234 wrote:I can only think of some arcade board and Neo Geo MVS stuff really, but by this point most people using those already know the deal.
Yeah my MVS converts to CSync internally so it should be safe.

Is it really only arcade stuff that used TTL?
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Guspaz
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Re: How to Determine TTL Sync

Post by Guspaz »

Tempest_2084 wrote:
fernan1234 wrote:I can only think of some arcade board and Neo Geo MVS stuff really, but by this point most people using those already know the deal.
Yeah my MVS converts to CSync internally so it should be safe.

Is it really only arcade stuff that used TTL?
Almost all home consoles that output csync (SNES, Genesis, Master System, Saturn, etc) are sending it TTL. It's up to the cable to convert it. Remember, csync can be either TTL or 75ohm, and it's almost always TTL on the console side.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

Ok so it really is up to the cable then. What would be the advantage of a cable doing TTL sync? By this I mean why would anyone make a cable that did TTL sync instead of Csync? Does it generally matter unless you're using something like a 5X?
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Re: How to Determine TTL Sync

Post by fernan1234 »

Tempest_2084 wrote:Ok so it really is up to the cable then. What would be the advantage of a cable doing TTL sync? By this I mean why would anyone make a cable that did TTL sync instead of Csync? Does it generally matter unless you're using something like a 5X?
For people connecting directly to pro monitors or stuff like Extron switches it wouldn't matter, since those have wider voltage tolerances for the video and sync signals. I guess it would let you make cables without needing to add attenuation but that's it.
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Guspaz
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Re: How to Determine TTL Sync

Post by Guspaz »

Guspaz wrote:I don't want to speak authoritatively on Mike's behalf, but sync-on-luma ought to equivalent to cvbs sync from a compatibility standpoint.
Quoting myself, I just realized that the 5X's manual explicitly says that 75 ohm terminated sync on luma is supported.
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

fernan1234 wrote:
Tempest_2084 wrote:Ok so it really is up to the cable then. What would be the advantage of a cable doing TTL sync? By this I mean why would anyone make a cable that did TTL sync instead of Csync? Does it generally matter unless you're using something like a 5X?
For people connecting directly to pro monitors or stuff like Extron switches it wouldn't matter, since those have wider voltage tolerances for the video and sync signals. I guess it would let you make cables without needing to add attenuation but that's it.
Ok that makes sense.

So it appears my choices are:

1. Crack open each of my cables and see if I can find some evidence that they're doing CSync instead of TTL (look for resistors?). But this isn't 100% fool poof and might be beyond my technical skills
2. Route everything through my Shinybow and use component out like I'm currently doing. Mike says I won't notice a difference and I'm inclined to believe him on that. The only downside is I'll need a switchbox for my GC and PS2 inputs which may degrade the signal (it's a Monoprice CPX-401, no idea how good/bad it is)
3. Buy all new cables and make sure they're not TTL Sync. Given that I need about 8 and one (my TurboDuo) had to be custom made this may be an expensive problem as the decent ones seem to be $35+

I'm inclined to go with option 2 and maybe eventually 3 if I can find a good deal on quality cables for multiple systems somewhere. Any suggestions on that front? I'd need cables for:

NES
SNES
N64
Genesis 2
Saturn
DC
TurboDuo
XBox

My PS1 cable is an Insurrection Industries one (my only name brand) and I'm 99% sure they don't use TTL Sync so that one should be ok. My Neo Geo does CSync internally so that one is good too. I plan on switching my PS2 to component cables so I don't need a new one there.
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maxtherabbit
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Re: How to Determine TTL Sync

Post by maxtherabbit »

C-sync and TTL are not mutually exclusive terms. You keep saying "csync or TTL" like they are

C-sync refers to the *type* of sync (composite sync meaning horizontal and vertical sync combined (not to be confused with sync on composite video))

TTL refers to the *amplitude* of the sync signal, its lower voltage counterpart is "video level sync" AKA 75 ohm sync
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Tempest_2084
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Re: How to Determine TTL Sync

Post by Tempest_2084 »

maxtherabbit wrote:C-sync and TTL are not mutually exclusive terms. You keep saying "csync or TTL" like they are

C-sync refers to the *type* of sync (composite sync meaning horizontal and vertical sync combined (not to be confused with sync on composite video))

TTL refers to the *amplitude* of the sync signal, its lower voltage counterpart is "video level sync" AKA 75 ohm sync
Ok so it's not CSync it's 75 Ohm sync? Gotcha.
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