Connecting HAS V5.0 to gscart 8:2 automatic SCART switch. Looking for advice and possible consequences

[DorianGray]

According to the distributor's website, connecting a supergun to the gscart will "permanently damage the switch."

The switch is already on its way, so let's assume I am committed to trying it (and I'm aware of the alternative switches). The goal is to have my CPS3, CPS2, and NAOMI 2 all running into one PVM. I also want to be able to switch between all 3 without having to unplug anything, swap cables, etc., while having the whole setup look as clean as possible with little to no exposed cables. The setup diagram and actual setup are below.

I did some internet research and found other people who have tried and it looks like I should be OK.

Does anyone else have any experience, suggestions or warnings with this setup? Are there any settings I can change on the HAS to prevent damage to the switch or am I realistically good to? go?

 

[Zepherino]

I don't think the video level would be a concern for blowing up the gscart immediately. I imagine the video would be overblown and it wouldn't be good for the components, but it shouldn't just kill it. I'd be more worried about pushing line level unmodified JAMMA audio into the gscart. Others more knowledgeable than me can chime in, but line level JAMMA audio would be my primary concern if I decided to use a gscart in my video chain (which I have never, since I don't have one).

It would be kinda janky, but I guess you could cut the audio pins in the mini 8 din cables to avoid damage (assuming my guess of audio being the biggest danger is correct). All of your boards support stereo, so I assume you would be using external speakers anyways, and if you weren't planning on this, I highly recommend that you do. Besides stereo seperation theres a substantial difference in audio quality going from arcade unamped mono to amplified stereo.

EDIT: I'm pretty sure I goofed and mixed up my terms... Basically JAMMA boards typically output mono audio designed to power the speakers in an arcade cab directly, which is the likely culprit for damage on switchers/consumer focused gear. As nam9 mentioned audio needs to be attenuated to prevent this.

 

[nam9]

I think it was mainly issues with superguns sending amplfied audio through the gscart that caused problems.
This just sounds like them looking to put people off from using superguns altogether, rather than have to build in protections on each input to counter people connecting all sorts of things up to these switches.
I would have confidence in the HAS v5.0 properly attenuating audio and video to Scart standard levels.
For anything esle, if you don't know... check first.

 

[MickyMac]

If your tv has 2x scart sockets, put gscart into scart #1 and the HAS into scart #2.

I've an old gscart 3.4 model and some of the chips failed on me when using HAS. Could have been a coincidence or a bad arcade pcb. After I fixed it (checking notes here, I had to replace
U14: ISL4089IBZ and U15/U16: EL1883ISZ) I never connected HAS to it again.

 

[9999 Damage]

The creator, Superg, got annoyed because people kept blowing up their Gscart with >1V TTL sync voltage on video and amplified audio. The same could also damage a consumer TV or upscaler, not just Gscart_sw/Gcomp_sw.

You just need to make sure you’re sending 75 Ohm impedance sync for video and unamplified / line level audio. This is easy for HAS, because it’s 75 Ohm impedance by default (but double-check, since there is a setting for 5V TTL output) and AFAIK only sends line level audio.

 

[kazuo]

What damage & nam said; the issue was someone was using a SuperGun (I think it was from some place called Windy City or something?) and it was sending unattenuated audio, which ended up damaging the switch. Presumably, if you have audio properly attenuated, there shouldn't be any issues feeding it into a gscart, but know that if it blows up, superg will refuse to service it.

This of course also assumes you are sending properly-attenuated video to the switch as well.

 

[DorianGray]

Thanks for the input everyone!

If your tv has 2x scart sockets, put gscart into scart #1 and the HAS into scart #2.

I've an old gscart 3.4 model and some of the chips failed on me when using HAS. Could have been a coincidence or a bad arcade pcb. After I fixed it (checking notes here, I had to replace
U14: ISL4089IBZ and U15/U16: EL1883ISZ) I never connected HAS to it again.

My pvm has rgb, but no SCART. Hopefully my gscart won't end up like yours, I'll find out in a week or so.

I think it was mainly issues with superguns sending amplfied audio through the gscart that caused problems.

The creator, Superg, got annoyed because people kept blowing up their Gscart with >1V TTL sync voltage on video and amplified audio. The same could also damage a consumer TV or upscaler, not just Gscart_sw/Gcomp_sw.

What damage & nam said; the issue was someone was using a SuperGun (I think it was from some place called Windy City or something?) and it was sending unattenuated audio, which ended up damaging the switch.

The consensus appears to be audio from the HAS as the main concern. If that's the case, I'll give @Zepherino's idea a try and clip pins #1 and #2 on the 8pin cord, going from the HAS to the 8pin to SCART adapter. Hopefully this should minimize the risk of bricking the gscart? I am not expected any guarantees of success, and won't be mad if it gets bricked. Just looking to reduce the risk in hopes of getting everything to work.

All of your boards support stereo, so I assume you would be using external speakers anyways, and if you weren't planning on this, I highly recommend that you do. Besides stereo seperation theres a substantial difference in audio quality going from arcade unamped mono to amplified stereo.

I hadn't thought about what speaker setup I was going to run, but external stereo does make the most sense so I think I'll give that a try. Do I need to change any settings to get sound from the board or can I just plug in the cables and run them to my external speakers?

 

[9999 Damage]

From the HAS store page:

Consumer equipment friendly level CSync at ~0.4 Vp-p 75 Ohm impedance (can be set to TTL ~5 Vp-p 470 Ohm impedance).

Unbalanced audio output, attenuated to safe line level.

Sounds like it's already doing what you're planning to do.

TIL that HAS 5.0 is designed to mitigate damage from TTL Csync output to consumer equipment. From the manual:

4.4.3. TTL CSync Level
Changes the CSync level to TTL. The TTL level is designed in a way that it is still safe for
the consumer equipment in case you set it to TTL by mistake.

 

[Zepherino]

For CPS2/3 and Naomi it should just be plug and play (RCA to consumer speakers of choice) without the need to change settings. Even if there were settings these boards are new enough that you would be setting it a software based service menu instead of dip switches.

My advice before wasn't really directed at the HAS supergun, and more focused on the probable cause of what might kill a gscart. The HAS is likely fine with how it handles audio and video, as others have pointed out in the manual.

Clipping the audio pins would be for piece of mind, and probably not a big deal since mini din 8 cables arent expensive, but keep in mind that you will lose sound for any non-stereo JAMMA boards that you acquire in future.

 

[nam9]

Your HAS is not sending amplified audio over scart.
And before you break out the shears, plugging in the 3.5mm audio jack will cut the audio over the 8-pin DIN regardless.

Again, these issues arose from poorly designed SGs that weren't properly handling audio/video, or simply user error on devices that were less foolproof than the current crop of SGs available today. There are good reasons why you many want TTL level signals available, but the Gscart is geared towards consoles and comsumer hardware.

Read your manuals people.