GeorgeSpinner
Grand Master
Does the cbox pictured have -5v?
I have not seen one that takes 12v that also converts to -5v.
I have not seen one that takes 12v that also converts to -5v.
CBOX/JAMMA Box Questions
- Thread starter chaoschao
- Start date
Bigblue709
Enthusiast
Mine appears to. I’ll check it with a multimeter if I think of it when I get home.
JonathanGene
Student
it seems random
everyones box in the thread has slightly different internals
i was the unluckiest, but what else is new? lmao
everyones box in the thread has slightly different internals
i was the unluckiest, but what else is new? lmao
GeorgeSpinner
Grand Master
Thanks but the cbox pictured in the OP is a big red PCB that looks nothing like yours. Unless that's some type of attachment I'm unaware of?Mine appears to. I’ll check it with a multimeter if I think of it when I get home.
Thanks again.
Bigblue709
Enthusiast
They broke out the JAMMA blade in later models. More pics below including board revs. Pretty sure this is the same maker? Could be wrong
GeorgeSpinner
Grand Master
Very cool! Thanks a lot!They broke out the JAMMA blade in later models. More pics below including board revs. Pretty sure this is the same maker? Could be wrong
Bigblue709
Enthusiast
Bigblue709
Enthusiast
I recorded some video to get an idea of the input lag with this unit.
Equipment: DualShock4, Magic-NS adapter (Xinput), Super CBOX 4.0, PGM, JVC AV-27020. Video recorded at 240fps on iPhone 8 w/ tripod; still frames taken from Adobe Premiere.
Total time from the button press to the change appearing onscreen: about 33.33ms, or two frames of video (= 8 frames at 240fps)
1: The button is pressed
2: The LED lights up
3: The test menu registers the press
I’ll try wiring a button to the SNK connectors later.
Equipment: DualShock4, Magic-NS adapter (Xinput), Super CBOX 4.0, PGM, JVC AV-27020. Video recorded at 240fps on iPhone 8 w/ tripod; still frames taken from Adobe Premiere.
Total time from the button press to the change appearing onscreen: about 33.33ms, or two frames of video (= 8 frames at 240fps)
1: The button is pressed
2: The LED lights up
3: The test menu registers the press
I’ll try wiring a button to the SNK connectors later.
Unsure about power alongside all the other connections traveling down the wires of that cable to the extension PCB.
That’s the main issue people face with cheap JAMMA harnesses (using thin wires for power).
Worth noting for sure.
That’s the main issue people face with cheap JAMMA harnesses (using thin wires for power).
Worth noting for sure.
JonathanGene
Student
maybe retest also with a normal wired db15 controller instead of all that signal chain too just for comparisons sake
i dont really have a way to run 240p test suit over the jamma edge (but thats an informal test anyway)
i dont really have a way to run 240p test suit over the jamma edge (but thats an informal test anyway)
Bigblue709
Enthusiast
Great point. What sort of problems might stem from this? Maybe I’m experiencing them already. I’m not very well-versed on all this stuff yet.
Power should travel on higher gauge (thicker) wires. The wires bundled in that connector are most likely very thin.
In an ideal situation all the wires in that cable should be individually shielded to protect from crosstalk/interference, the power and ground wires should be a thicker gauge and separately shielded, then the entire cable should be shielded and protected from interference. I doubt that’s the case.
Voltage drop and fluctuations, video noise, heat and other weird stuff might happen. Then again. It might not, just throwing it out there.
In an ideal situation all the wires in that cable should be individually shielded to protect from crosstalk/interference, the power and ground wires should be a thicker gauge and separately shielded, then the entire cable should be shielded and protected from interference. I doubt that’s the case.
Voltage drop and fluctuations, video noise, heat and other weird stuff might happen. Then again. It might not, just throwing it out there.
Bigblue709
Enthusiast
Makes sense.
The cable contains 24ga wires and is about 2.5-3 feet long. The main unit gets a bit warm around the power regulators, but that’s about it so far. I’ll keep a close eye on it; I don’t plan on connecting anything rare or expensive to it.
I’m trying to round up a few more CRTs for testing — I’m hesitant to judge the picture quality based on one tube.
The cable contains 24ga wires and is about 2.5-3 feet long. The main unit gets a bit warm around the power regulators, but that’s about it so far. I’ll keep a close eye on it; I don’t plan on connecting anything rare or expensive to it.
I’m trying to round up a few more CRTs for testing — I’m hesitant to judge the picture quality based on one tube.
GeorgeSpinner
Grand Master
I decided to order one of these Chinese cboxes.
While it does output -5v, no PCB that uses -5v actually works with this cbox; none of them have working sound.
Anyone have an idea why that would be?
Edit: there is some sound on -5v PCBs but it's very distorted and very very very (that's right, 3x very) faint.
I'm guessing there's not enough amperage on the -5v line. I order a new multi meter. I'll test it out when it arrives.
If that's the case, I'll try to remedy it somehow.
While it does output -5v, no PCB that uses -5v actually works with this cbox; none of them have working sound.
Anyone have an idea why that would be?
Edit: there is some sound on -5v PCBs but it's very distorted and very very very (that's right, 3x very) faint.
I'm guessing there's not enough amperage on the -5v line. I order a new multi meter. I'll test it out when it arrives.
If that's the case, I'll try to remedy it somehow.
Last edited:
GeorgeSpinner
Grand Master
I got to the bottom of the Chinese cbox no/low/extremely distorted sound issue on some PCBs.
The issue seemed like it was related to PCBs that require -5v but other PCBs had the same issue as well.
The Chinese cbox has JAMMA PIN 11 connected to ground. I did not bother to check the solder side equivalent (M).
Filtering out pin 11 (and M) with a passthrough PCB resolved the issue.
The issue seemed like it was related to PCBs that require -5v but other PCBs had the same issue as well.
The Chinese cbox has JAMMA PIN 11 connected to ground. I did not bother to check the solder side equivalent (M).
Filtering out pin 11 (and M) with a passthrough PCB resolved the issue.
kinooshi823
Professional
I just purchased this supergun pictured. So from what I read here, I would need a much better 12v power supply right? I also have a retroelectronik supergun but scart doesn't seem to work, and I can't find an NTSC encoder anywhere on the net. I had one built 10 years ago with a JROK encoder and my mom threw it out 
Attachments
GeorgeSpinner
Grand Master
I'm using the power supply that came with it. Works with everything so far.I just purchased this supergun pictured. So from what I read here, I would need a much better 12v power supply right? I also have a retroelectronik supergun but scart doesn't seem to work, and I can't find an NTSC encoder anywhere on the net. I had one built 10 years ago with a JROK encoder and my mom threw it out
Everything = cps, MVS, taito F3, Double Dragon II, Rastan, Final Blow, Vigilante, hit the ice, super volleyball, and more.
kinooshi823
Professional
I bought it so I can dust off my tekken boards and my 246
GeorgeSpinner
Grand Master
Cool.
Just make sure you read my post about pin 11/M.
Just make sure you read my post about pin 11/M.
kinooshi823
Professional
I have this pictured below. Would that work? or can you send me a pic of the PCB passthrough. Also, would soldering off 11/M work as well?
