JPAC + Audio = HELP! - Amp recommendations?

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    • JPAC + Audio = HELP! - Amp recommendations?

      Okay, so I finally threw MAME in one of my CRT cabs (the Swing!). And crt_emudriver / GroovyMAME / etc were a breeze. Done that part a few years back, but with an NNC so I'd just used a JVS-Pac and routed audio through the built-in amp.

      Well I had misunderstood how the JPac "handles" audio (it doesn't do anything except route the audio from an external amp to the JAMMA edge), and am now in need of some advice on what audio amp to buy. It needs to be USB powered so I can keep everything neat and tidy inside the cabinet. Outside of that, it just needs to work, I don't need anything fancy.

      Maybe paging @acblunden2? I know you do attractmode setups (I actually installed your preferred theme from another thread and am enjoying the simplicity of it).

      Anyone else's recommendations are also super welcome!
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • Rg111 wrote:

      I use that one also. Works 100%.
      Cabs currently own: Egret II, New Net City
      Cabs no longer owned: Mini Cute, New Astro City, Egret II, Sammy Tosh, CrossXBeats Rev. Sunrise, Jaleco Pony Mark IV
      Systems/PCB currently own: Naomi (netboot), ST-V (multi), Die Hard Arcade
      Systems/PCB no longer owned: Street Fighter II: WW, Namco System 256 w/ SC III: AE, Sega Lindbergh
    • digitron wrote:

      rewrite wrote:

      Grabbed one of each, we'll see how it goes!

      Thanks @acblunden2 and @Rg111
      Curious how this turned out once you get it setup.
      I would say I'll update this thread when they come in, but I will forget. Ha. Remind me in 2-3 weeks and I'll let you know!
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • Question regarding the JPAC, from their website it says: - "There will therefore be a period of time at start-up when the PC will not be providing the correct output for the arcade monitor. The special circuitry on the J-PAC will ensure the monitor does not attempt to operate outside its range."

      Is that a for sure thing? I'd rather not flash ATOM bios, I had to restore it on another machine last time because my card doesn't like it for some reason.

      When my windows 7 pc boots, the screen goes out of range, I know that it's running outside of 15Khz during boot, until crtemudriver kicks in...I just want to be sure the JPAC is actually still keeping it 15Khz during this time? This was one of the nice things about running my old Extron on my groovymame seutp before I got a cab, it would show the actual frequency on a little lcd so I knew when it was safe to turn on the crt.

      This is also a friendly reminder for rewrite to tell us how his sound project is going. =)
    • It doesn't change the resolution to 15k during boot. It just passes the video through, not downscale it. I just turn on the PC, wait twenty seconds, and turn on the cab.

      No updates because both packages are still in transit. They passed through ISC New York about a week ago so I'm hoping they show up soon.
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • Flash your Radeon card with ATOM-15. Works great. Save your OG BIOS and you can flash it back anytime you like. I use WinFlash and it works fine in Windows. Never had a problem. (EDIT: Interestingly enough, all the issues I've had with ATOM-15 was when I used the DOS version of ATIFlash. WinFlash seems to be much more stable for me. Perhaps the key is a clean install of Windows is needed). All the Radeon cards I've ever flashed are HD7000 series or lower. No need to go higher for MAME since MAME doesn't offlload processing routines to the CPU. All my MAME builds are all fresh installs of Windows. I don't take a PC that has been used for Desktop applications and just decide to use it for MAME. I wipe it clean and only install updates needed to run MAME. Here is a great tip for ppl wanting to setup MAME:
      • Create a Restore point for every step you go through when setting up MAME
        • Restore Point 1: Base Windows and driver Install
        • Restore Point 2: MAME roms and front end copied over
        • Restore Point 3: Windows Updates Applied and base programs installed
        • Restore Point 4: CRT Emu Installed
        • Restore Point 5: MAME and front end controls/navigation configured
        • Restore Point 6: Hide Windows Complete
        • Restore Point 7: CRT Emu installed/Modes Installed/Front End shelled
        • Restore Point 8: EIDID Enabled in CRT Emu
      • If your PC takes a dive anywhere along the process, you can restore it and be back in business
      In answer to your question, J-Pac takes the 31khz signal and divides the frequency to 15khz so it can be displayed on a 15khz monitor without damaging circuitry. You get a horizontally split screen. J-Pac sucks in general if you ask me, so I skip it. I always use ATOM-15 because the safeguards in J-Pac while functional, are not practical. There are times when I need to see the BIOS screen on my arcade monitor. Plus aesthetically, seeing the BIOS image is more pleasing than a blurry horizontally split screen on my arcade monitor.

      The post was edited 3 times, last by acblunden2 ().

    • Neat to know it's capable of halving the video signal. Doesn't help for > 31k. But still useful in a pinch. I've yet to mess with atom15, and at least right now don't have a need to, but when I put the PC in another cab, or setup another one I may.

      If you want to run demul or that model 3 emulator you may want a beefier GPU.
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • rewrite wrote:

      If you want to run demul or that model 3 emulator you may want a beefier GPU.
      True that.

      Man, this week alone, I've put together 4 MAME PC's for CRT-based cabs. I think I have another 4 more to go. Been knocking them out in 2 hours flat. No J-Pac's used and the requisite expense saved.

      Here is another couple additional tips for those that use Windows 7 64-bit:
      1. Don't use UEFI to install Windows
        • Use Rufus and write your USB stick to BIOS boot
        • That way you can use Daz Windows Loader to register Windows
          • It's simply the best Windows 7 key gen and saves yourself some dough
      2. To hide Windows, follow this guide up until this step:
        • Change boot animation
      3. Once you get here, skip to below step:
      4. Then run Instantsheller
        • This is the quickest possible way to hide Windows 7
      5. Also, I use Instantsheller so I can use the boot logo attached below
      6. If using AttractMode w/Instantsheller, you have to do another step in the registry outlined here so that it shells correctly
      • Winners_Dont_Use_Drugs_8377.png

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    • thomas3184 wrote:

      Zero delay usb pcb
      I forgot about these, honestly. I actually have one just sitting in my closet.

      digitron wrote:

      Wonder if he's splicing wiring so he can also connect a jamma board or if this setup is exclusively for mame cabbers.
      I believe acblunden2 sells them on. So there wouldn't necessarily be a need to keep the JAMMA harness intact. I'm curious too.

      I'd need to crimp all new connectors and all that for the zero delay. And the monitor in the Swing isn't a D-sub connector (not to mention I thought the j-pac did all the audio handling), and it just seemed way easier to j-pac it.
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • I use Zero Delay Encoders for MAME-to-JAMMA controls. I skip the J-Pac. I just don't like the quality of the onboard video amp (it's 10+ years old now); find it to be lacking in contrast. I liken the image produced from the J-Pac to looking at an arcade monitor with sunglasses on. The whites are crushed. In most US-based cabs, I can get away without an amp entirely on MAME builds. But if not, I use a THS-series RGB amp and made a PCB project for that to suit my needs. Also, don't like keyboard emulation that J-Pac uses and find it to be a bit laggy across different PC's at times. Don't know why that is so. But the Zero Delay Encoders take care of that entirely. Also, I like to keep MAME builds as low cost as possible. A J-Pac is $60. An ArcadeVGA is $80+. I always use a HD5000-7000 series Radeon card. I buy them in large batches from eBay for $5 each. Zero Delay Encoders are $5 each, sometimes less. I always buy these things in bunches when I see good deals on them on eBay.

      If I have a cab where I know it will always be used for MAME, I just gut the wiring harness and repurpose that harness for other things. Remove the PSU and keep it for stock/a rainy day, or sell it to recoup some cost. Then, I'll wire video output right to the chassis after breaking out RGB/VGnd/H&V Sync (tied together) with a VGA breakout terminal. I tap AC from somewhere in the cab to power a 12v DC adapter to power a stereo amp. Then rewire the cab for stereo output from the PC. Always, always I fashion a splitter or use a power distribution block when tapping power. Once I build a MAME cab and send it off, I don't want it burning down someone's house. Also, I keep everything powered from one AC input which is controlled by a rocker switch. To achieve this, I go into the PC's BIOS to setup 'Power On' after 'AC Restore'. I'll hack up an AC power cord and wire that to a power distribution block, along with the monitor AC power, stereo AMP AC power, and marquee AC power. The marquee's AC power is very important. Because to turn off the MAME cab, I set the front end to shut down the PC upon exit. Once the PC is shut down, the monitor goes black and you wouldn't know the cab is on if there is no marquee light. So after the PC shuts off, the swich is flipped off cutting power to everything. Then powering it back on is just a matter of flipping the AC switch on. You'll always know the cab is on if the marquee light is on in my builds. I think others use smart power strips. Those things cost $30. Why have that expense?

      If I need to keep the harness intact (like when setting up MAME in Candy cabs), I'll solder all non-controller inputs to a JAMMA fingerboard. Then use Dupont wires for controller signals after soldering a 2x10 console header to a finger board. That is why I like the PB.JAMMA so much for this purpose. Plus, I can tap 12vdc from the PB.JAMMA to power the stereo amp. PB.JAMMA allows me to use multi-console PCB's for consoles and such, so I dig the flexibility it affords over the J-Pac. Sometimes, I will create a harness and wire it right up to the CP, like I did here.

      Get a load of this "ghetto" setup I am working on right right as of this moment:

      This may seem really ghetto with a Windy II's CP being propped up by Coke cans. But this ghetto setup belies a truly functional application for this purpose. That CP is getting ready to be stripped of its CPO. The panel repaired as rust is eating away at it. But before it gets that TLC and since we are at my buddy's office, it makes for a good make shift rig to config MAME cotroller inputs as well as the front end's navigation inputs. All of this shall be thrown into a Sega Versus cab later. Once I have MAME and the the front end's inputs configured (in this case AttractMode), I can just copy the config files over and over. Those LCD's you see there are displaying a misaligned impage are displaying a 15khz signal from a single Dell Radeon 5450 card ($5 bucks shipped!) running CRT Emu. Such LCD's are a god send if you ever setting up MAME. I wouldn't even dare setup MAME without such an LCD. Too troublesome. It is worth your time to find an LCD that can display a CRT Emu hacked 15khz signal through VGA. With it, you can set everything up from the comforts of your desk. Then once done, shut it down and all you need to do is wire in your PC to your cab and you are good to go.

      All of this is pretty simple once you've mastered the software setup of MAME. Anyone on this forum can do the rest. I am sure there are much more experienced people at crimping and soldering then me here.