Console JAMMAizer. Easily connect home consoles to your JAMMA arcade cabinet.

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    • Console JAMMAizer. Easily connect home consoles to your JAMMA arcade cabinet.

      Since I recently took delivery of a New Net City I've been in need of games to play on it. The only arcade PCBs I currently have are CPS2 titles, Including one Multi kit. The CPS2 is great and all, but I want to play some 3D fighters, and I'm not ready to invest in a NAOMI setup yet. Therefore I have put together a PCB to help me connect my Saturn, PS1/2 and Dreamcast to my NNC. The JAMMAizer! (not to be confused with the JAMMAfier)



      This board takes RGB SCART input and passes it to the JAMMA edge, audio is output through 2 RCAs which can be connected to the cabinet's amplifier, and controls are meant to be handled by a pair of Brook Retro Boards connected via 20 Pin Harness. Kicks are output to a CPS2 style kick harness connector. This first version is fully passive, It doesn't amplify the video or audio meaning that it will only work properly with a Tri-Sync monitor and a stereo cabinet with a dedicated audio amp. I hope to evolve this into an active design that amplifies the audio and video so it can be used on 15khz only monitors and Mono cabinets. This is just the first step to get it running on my personal setup. I will be using this with my NNC through @invzim's JAMMAfier.

      Here is a link to OshPark where you can download the gerbers if you want to have this manufactured. I do have a small batch in production right now which should be delivered some time next week if anybody wants one.

      Thanks for checking out my project!
      plus ça change,
      plus c'est la même chose,
      The more that things change,
      The more they stay the same.- RUSH- Circumstances

      The post was edited 1 time, last by Arthrimus ().

    • New

      I've made some headway on the active version of this design. I've implemented a THS7375 video amp/buffer which has 15db of gain to bring the voltage up to arcade monitor territory. I also added an LM1881 sync stripper to deal with sync on luma, sync on composite consoles like the PS1/PS2. For sound I have added a stereo summing circuit with an LM386 mono amplifier and a potentiometer for volume control. I still have to breadboard these amp circuits to make sure I haven't screwed anything up so this version isn't production ready yet. Hopefully I can have everything tested sometime next week.

      plus ça change,
      plus c'est la même chose,
      The more that things change,
      The more they stay the same.- RUSH- Circumstances

      The post was edited 1 time, last by Arthrimus ().

    • New

      Thanks for the compliments guys.

      I have done some more work on the board layout, changing out some components due to poor availability/obsolescence. I also added a switch to send audio either to the JAMMA edge or to the RCA jacks rather than having both connected all of the time.



      As a companion to this project I also put together an MC Cthulhu replacement PCB that matches the Brook/PS360 layout. Here is the OSHPark link.


      And here is the first prototype PCBs that I received yesterday.



      plus ça change,
      plus c'est la même chose,
      The more that things change,
      The more they stay the same.- RUSH- Circumstances

      The post was edited 1 time, last by Arthrimus ().

    • New

      Great work man. I don't know if it makes sense, but maybe on that audio switch, have it as a 3 way switch, either, or as a third option, both. I don't know if this would be a needed feature, but perhaps there is a situation where someone would want it going to the cab and also coming off the board to be captured for some reason.
    • New

      Excellent, excellent work brutha. Been ramping up my non-existant PCB design skills so that I can get to this point. But looks like I can divert those energies elsewhere, because what you are doing is what I've been trying to work towards for a long time.

      Absolutely, love that you realize that leveraging MC console PCB's to handle controls is the way to go. I think with other efforts, the engineers saw controls as something their skills could be leveraged to solve. Such a wasted effort and an additional expense for the potential user market IMO. MC PCB vendors specialize in this and do it exceedingly well. No point in wasting their talents to solve for controls. Also,procuring an MC PCB still allows you to use them in fight stick applications. It is a complete win to use MC PCB's for this application.

      Couple of things for your consideration:
      1. JAMMA audio needs to be amped mono before outputting to the edge connector
        • Let's discuss this further
      2. DC coupling the RGB output is required to be compatible with all arcade monitors
        • The THS-Series amps are capable of doing this
        • 15khz RGB video from consoles is AC-coupled
      3. Adding a VGA video input would allow this to be used with MAME, replacing and improving on the J-PAC
        1. This is a nice-to-have but if implemented would allow for use with for MAME at the same time as for use with consoles
        2. This would also necessitate audio input and an onboard amp
      All in all, I love this! Would love to volunteer to QA it. Thanks!
    • New

      acblunden2 wrote:

      Excellent, excellent work brutha. Been ramping up my non-existant PCB design skills so that I can get to this point. But looks like I can divert those energies elsewhere, because what you are doing is what I've been trying to work towards for a long time.

      Absolutely, love that you realize that leveraging MC console PCB's to handle controls is the way to go. I think with other efforts, the engineers saw controls as something their skills could be leveraged to solve. Such a wasted effort and an additional expense for the potential user market IMO. MC PCB vendors specialize in this and do it exceedingly well. No point in wasting their talents to solve for controls. Also,procuring an MC PCB still allows you to use them in fight stick applications. It is a complete win to use MC PCB's for this application.

      Couple of things for your consideration:
      1. JAMMA audio needs to be amped mono before outputting to the edge connector
        • Let's discuss this further
      2. DC coupling the RGB output is required to be compatible with all arcade monitors
        • The THS-Series amps are capable of doing this
        • 15khz RGB video from consoles is AC-coupled
      3. Adding a VGA video input would allow this to be used with MAME, replacing and improving on the J-PAC
        1. This is a nice-to-have but if implemented would allow for use with for MAME at the same time as for use with consoles
        2. This would also necessitate audio input and an onboard amp
      All in all, I love this! Would love to volunteer to QA it. Thanks!
      Thanks, I actually looked at your thread early on when I was doing research for this project.

      As for your list of considerations:
      1. I am currently using an LM386 audio amp for the mono audio output to the JAMMA edge.
      2. I am using a THS7375 amp for dc coupling and amplification.
      3. That is probably outside of the scope of this project at the moment.

      opt2not wrote:

      Good call on the MC Cthulhu! Still a very popular board.
      I know, I have 4 of them, probably will have more in the future as I do more projects like this. The nice thing about my custom MC Cthulhu board is that if you build it the only special part you need the PS3 Cthulhu to MC Cthulhu upgrade chip from Paradise Arcade Shop.
      plus ça change,
      plus c'est la même chose,
      The more that things change,
      The more they stay the same.- RUSH- Circumstances

      The post was edited 1 time, last by Arthrimus ().

    • New

      Arthrimus wrote:

      I know, I have 4 of them, probably will have more in the future as I do more projects like this. The nice thing about my custom MC Cthulhu board is that if you build it the only special part you need the PS3 Cthulhu to MC Cthulhu upgrade chip from Paradise Arcade Shop.
      That's fantastic. And really, I'd love to use this to replace my old MC Cthulhu's in my fightsticks now since it can be directly mounted on top of a Brook UFB. I have one of my sticks with the Jasen Customs EZ board he put out a while ago with the USB problems (which is why he discontinued it), but I only use the RJ45 function in parallel to my UFB.

      Kinda hard to tell, but it's under my UFB here:


      Dual ports:


      Could your EZ board work the same way, as a standalone MC Cthulhu in a fightstick? Or is it specifically for the Jammaizer?

      In either case I'd be happy with it. :)
    • New

      It definitely works like a normal Mc Cthulhu. Part of the reason for designing this board was to make it easy to interface with a Panzer Fight Stick that I'm having Jasen make for me. I already have one of these wired up in one of my arcade sticks. If you want some I have extra blank PCBs made right now.
      plus ça change,
      plus c'est la même chose,
      The more that things change,
      The more they stay the same.- RUSH- Circumstances
    • New

      For anyone who is interested in purchasing the MC Cthulhu EZ PCB please PM me for details.

      I have been able to do some prototyping for the RGB amp circuit and this is where it sits currently.



      This is tested and working great through the 15Khz input of my Toshiba PF monitor in my New Net City. The THS7375 ups the ~.7v SCART video input to ~3.5v which is enough that it looks great on my monitor. I actually had to add some resistance on the output side because it was actually overdriving the RGB input of my monitor resulting in oversaturated colors. I accomplished this by adding 1K potentiometers in series with the RGB output from the amp that can be adjusted to suit your monitor's needs. Mine looks best with 475Ohms of output resistance, your mileage may vary.

      Unlike the amp circuit in @acblunden2's thread, I could not get this working properly without adding .1uF capacitors to the input of the THS7375. Without capacitors I got brightness fluctuations depending on the overall brightness of each scene. With the capacitors in place the brightness is rock solid. I suspect this may be down to a difference between our monitors, but after reading through the THS7375 datasheet I believe my circuit is correct for this application.

      Next I need to prototype the sync stripper and audio amp portions of the design. Once those and the PCB are finalized I think I will be ready to do a small run of the finished design.
      plus ça change,
      plus c'est la même chose,
      The more that things change,
      The more they stay the same.- RUSH- Circumstances
    • New

      Your circuit is likely correct and mine is wrong. I haven’t had success with my PCB. But it has worked sans PCB in the past. In all honesty, I have not touched my PCB project in a while. Soooo many other projects ahead of it. Interstingly enough, will get some work on it tonight for MAME. But if your’s proves correct, I’ll implement it in mine. I’ll probably stop investing time in my project after that since what you are doing literally achieves what I’ve beed hoping for for 2+ years now. My project likely will exist from then on for quick and dirty MAME conversions for gutted cabs.
    • New

      That Cthulhu board deserves its own thread!! Nice work! I was a fan of @JasenHicks design a while back, but he had some issues with them so they were discontinued. Glad to have an alternative surface!

      Maybe @Darksoft or @brizzo can get you a section in the User Created Products part of the forum too, especially if you have more cool stuff up your sleeves. (And guys maybe @invzim should get one too just sayin)
      multis: cps* ttx2 gnet f3 mvs sega st-v/16b/24/c2/naomi(netboot) sys2x6 m72
      cabs: sega blast city x2 | taito vewlix c + egret ii
      links: klov/vaps games list | custom fight sticks
      projects: conversions, various repairs