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Minigun Supergun - An Open Source Supergun

@Frank_fjs, I just noticed something and it's surprising that I would be the first one to report it. The LPF On/Off switch is wrong (I'm using the DIN8 version of the board): it's on when the switch is left (i.e. the bypass pin on the THS7374 is to ground) and off when the switch is right (i.e. the bypass pin on the THS is at 5V), which is the reverse of what the silkscreen on the board indicates. I first noticed by looking at the signal through my oscilloscope.

I think it's due to the fact that the slide switch is behaving in a non intuitive way: when the switch is on the left it connects the two legs that are at the right of the switch, and vice versa.
 
cpasjuste said:
So First, i'd like to know if you see a problem with that. I mean, i know that a 5v 2/3a adapter should work with the "stereo modded" mvs1b, but do you see any problem which could occur with that ?
Next, i'm "playing" with EasyEDA for the first time, i placed a micro usb connector, but i'm not sure how (if possible, as all is already very optimized by you) to cleanly route it to +5v and gnd. Do you think it's possible (see pic)? Do you think you could add it in your "stock" design as it could be interesting for some mvs users (at least?)? I'm not even sure i did choose the best micro usb socket...
Click to expand...

I'm doing something similar with a MVS MV1C: I only supply 5V. I actually use a barrel jack for that instead of microUSB. Those microUSB connectors are super fragile, I wouldn't really recommend it. If you really want to use a USB charger, you can still find USB to barrel jack cables easily. That being said, be careful about supply noise. I use a high quality regulated 5V power supply and it makes a *HUGE* visible difference from a noisy power supply (which most USB power supplies are).

It's especially visible if you run the video signal through an ADC (like OSSC) to display on a flat pannel and if you want to avoid using a LPF (or can't because you're using AV3 on the OSSC).
 
I've also found that the quality of the power supply greatly affects picture quality if you're the kind of person who notices that sort of stuff.
 
I just acquired a Minigun Supergun and it's amazing. However, neither of my Sega System 18 games will work properly. Moonwalker and Shadow Dancer both have severe sync issues. Any advice for a fix?
 
@KCgametser that’s probably just system18, not the supergun. What monitor / video-chain are you using? On my blast city I have to adjust horizontal sync a smidge to get it to lock.
 
Sony model # PVM-2950Q. All my other boards work perfectly fine including Sega system 16 games. The system 18 games Moonwalker and Shadow Dancer both have sync issues.
 
You should look up service mode for that unit, it’s probably pushing menu then holding enter and degauss. Then see if you can adjust your h sync. alternatively you could try an external sync tool like an extron. it’s not the minigun in any case. Some boards just have odd sync signals, system18 being one of them.
 
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@ekorz, Thanks for the advice. I appreciate it. My PVM does not have an H Sync adjustment in the service mode. An extron may be my only shot at this. And I agree, it's not the Minigun.

@Frank_fjs, Thank you so much for the Minigun. An absolutely incredible feat of engineering. My games look amazing on my PVM. Any other advice on system 18 games? I just want to make sure before paying money for an extron.
 
GeorgeSpinner said:
@KCgametser - You can try one of these image adjustment PCBs: https://www.arcade-projects.com/thr...rcade-monitors-2-solutions-inside.6771/page-2

I use one to get several boards to sync to my CRT an my flat panel. Also helps when the image is just a little off center.

They usually cost around $30. Check ebay and aliexpress.

The design has changed a little since that thread was created, but not much.
Click to expand...

So this board fixes sync issues as well? That's great. I might just get one.
 
I'm no expert at this, but I'd say: It can, and it has for me.

I have used this board to sync every PCB I own to my CRT TV, and it has helped me sync all those PCB but 1 (2 on 2 Open Ice by Midway) to my flat panel.

If you have a rolling image, this will probably fix you up.
 
GeorgeSpinner said:
I have a similar setup for my MV1C.

I'm going from USB to the 6-pin Molex.

Only supplying 5V requires the stereo mod, as you won't get sound from the JAMMA edge.

I use a raspberry pi 3 2,5A USB power supply.

The picture is nice and clear.
Click to expand...
Hi !

Thanks for the feedback! I did buy a (crappy) Chinese supergun for testing and added an micro usb socket to it, it works fine (without audio since I miss the components).
For the audio to work at 5v, I think we also need the 5v mod with the stereo one isn't it ? It seems to be the case, at least for the mv1b.

Edit: I did the "simple" (jnx?) stereo mod and routed that to the jamma stereo pins, all is working fine at 5v except the sound is too "soft/low" as reported by many users. So I did buy all the needed parts for the MKL one, and also ordered the parts for "my" supergun design (with micro usb for power), stay tuned ! :)
 
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Hey Guys,

Please excuse my ignorance, I'm sure this question has been answered multiple times on this thread and all over the forums, but could somebody recommend a good quality 9-pin Genesis 2 to SCART cable for the Mnigun? I'm thinking about trying one of these out prebuilt from Ebay.

Thanks!
 
Jorel81 said:
Hey Guys,

Please excuse my ignorance, I'm sure this question has been answered multiple times on this thread and all over the forums, but could somebody recommend a good quality 9-pin Genesis 2 to SCART cable for the Mnigun? I'm thinking about trying one of these out prebuilt from Ebay.

Thanks!
Click to expand...
https://retro-access.com/collection...esis-2-stereo-csync-rgb-scart-cable-lead-cord

https://www.retrogamingcables.co.uk...e-2-sega-genesis-2-rgb-av-scart-cable-tv-lead

https://insurrectionindustries.com/product/sega-genesis-model-2-rgb-scart-cable/

The coax option from retro access is definitely top tier and probably overkill.
 
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