jamma speakers

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    • I think it depends on the output rating of the sound amp in use on the game board. See the issue here:
      geoffthegreygeek.com/how-to-co…-speakers-to-1-amplifier/

      Question is.. do all game sound amps have the same requirements? Unlikely?

      The modded cabs I've seen have the jamma +/- wired to a cheap cabinet amp that can take mono input and output on 2 speakers, or have an additional stereo input too.
      That way you get the best of both worlds, you can rig your CPS2 up for Q-sound or take stereo right out of your MVS etc..
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    • SP+ and SP- doesn't refer to the positive and negative terminals of a speaker.

      On most standard Jamma games, audio is mono. You use SP+ and a common ground pin (Jamma pins 1, 2, 27, 28, A, B, e, f). So the speaker's positive terminal goes to Jamma SP+ and the speaker's negative terminal goes to any of the aforementioned Jamma ground pins.

      Some MVS boards output stereo sound from the Jamma edge. In these cases this is where SP- is used. So SP+ (right speaker positive terminal) and a Jamma ground pin (right speaker negative terminal) is the right speaker output and SP- (left speaker positive terminal) and a Jamma ground pin (left speaker negative terminal) is the left speaker output.
    • I think that's wrong. The aforementioned MVS boards aren't jamma, so they don't adhere to jamma spec.

      I always wire my speakers to SP+ and SP-. If the negative terminal is meant to be grounded then SP- and GND will show continuity. However, it's also possible both SP+ and SP- are floating (SP- goes below ground), which means if you wire the speakers to SP+ and GND, you will possibly blow the amp.
    • hm, now i`m confused...
      what caps should i use?
      so in jamma boards i dont need an amplifier or a high-low converter with unamplified speakers, but i see u have divergence in wiring them. another question: if the board outputs just mono, there`s no difference wiring the speaker - into a second speaker? And the boards that output stereo, like cps2, i can wire into the rcas, but i can use too the speaker - to output stereo?It will simplify trading the speakers to diferrent boards...
    • Hey,

      The caps don't apply in your situation. They're only needed if feeding the jamma speaker signal to an amp.

      Re the video converters, I do know how to construct both. Here's an RGBS to composite encoder I'm working on. Will also be adding s-video to it too.

      Component requires a few more parts but I have a PCB for that also.
      Images
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    • hm, so maybe u can help me out! Well, i would like to understand how to transform rgb into whatever signal haha and doing this myself.
      But know i have a little question about capturing arcade video:
      well, i just bought an avermedia that says ``capturing ps3 and xbox360``, component inputs/outputs. Well, i use a RGB->COMPONENT converter that i bought, but no signal from pcb! Just from ps3...
      Do u know why? And if it`s impossible with that capture card, what should i use? Can`t understand why it doesn`t work with arcade pcbs.


      Link for my capture card:
      controle.net/avermedia/placa-de-captura-game-capture-hd
    • TheBortot wrote:

      hm, so maybe u can help me out! Well, i would like to understand how to transform rgb into whatever signal haha and doing this myself.
      But know i have a little question about capturing arcade video:
      well, i just bought an avermedia that says ``capturing ps3 and xbox360``, component inputs/outputs. Well, i use a RGB->COMPONENT converter that i bought, but no signal from pcb! Just from ps3...
      Do u know why? And if it`s impossible with that capture card, what should i use? Can`t understand why it doesn`t work with arcade pcbs.


      Link for my capture card:
      controle.net/avermedia/placa-de-captura-game-capture-hd
      I'm not familiar with that exact capture device but chances are this will not work with low res video if you're getting it directly from jamma without an upscale in-between. There are definitely some old devices that work with low resolutions and maybe even a few newer ones. Not sure about inputs however: raw RGB vs component vs s-video vs composite. I personally do not use anything that natively works with low res but instead just upscale prior to capture, using a device like OSSC or something similar. Most capture devices on the market currently can work with 720p or better, some at 480p also I believe. Depending on the application (streaming vs local video capture) I'd say that should be your goal - upscale to 720p or 1080p prior to video capture.
    • so the problem is the resolution that arcade pcbs generate? Guess i can`t escape from buying OSSC no matter what capture device i use.

      Hmmm, there`s someway to convert component to s-video OR to composite? Well, i remember using ``easycap``, an USB capture device that indeed got CPS2 image, but i abandoned it because at that time i have a supergun incompatible with other pcbs. Guess if i have some device converting to s-video/composite, i can achieve some average recording quality for now.
    • indeed, i`ve already had an s-video/composite supergun, but it didnt work with cps3(just cps2 and neo geo). But when i got and rgb->component, it worked, dunno why! So, i`m trying to figure out how not to buy more things, but guess i `m going to=(.
      But do u guys have some scheme for making those converters? Well, my converter has a IC that isn`t anything written on it, maybe the owner erased it in a way to hide the name of it.
    • Sadly there's no universal direct video capture solution for all arcade gear. Way too many variables and it's very easy to fall down the video capture/scaling/streaming rabbit hole and start spending a ton of money. In that respect we're similar to console games too. That's just how it goes.

      Unless you just want to set up a tripod and shoot the screen. That's definitely easy, more universal and way cheaper but not nearly as fun or high quality.