A working Ps2 to arcade monitor adaptor?

[syntax_X]

Does anyone know a good link to geting a ps2 to work properly on an arcade cab. Using the ultimarc psx adaptor gives me a dark pic in ps2 and a light pic in ps1.

[Dave_K.]

Sounds like you bought the Ultimarc PSX to JPAC av cable, which does not have the video amplifier on it (since there is already one built into the jpac). You can buy the video amp separately on their website although you still need to wire up a molex connection from the amp to the monitor.

[syntax_X]

No, im not that stupid. monitor im using dont have a d-sub either.

I have the one with the inbuilt sync seperator circut and an amp.
its just way too dark on ps2, contrast is too low.

would it hurt adding another amp?

[rtw]

I have actually been investigation this issue, sadly though I don't have a
lot of time these days but I'll post what I have discovered...

I use two parts:

LM1881 - The PCB at the end of the PS2 cable from Ultimarc
JPAC - The JPAC, normally the LM1881 goes into the VGA connector here

It's important to use the cable supplied from Ultimarc when interfacing to
the JPAC i.e. the one on with the LM1881 sync splitter PCB on it.

The JPAC has an RGB amplifier built in. However the picture is very dark.
Instead of seeing the colour red I get close to black instead. Another
artifact is that the intensity varies on screen.

I have tried this on two monitors a PoloStar 25" and a Intervideo 25" with
the same result. Both inputs have been the 'proper' analog 1-5VPP input.

If I use the low impedance VGA connector input on the Hantarex directly
with the LM1881 all is good

You must NOT use a normal SCART cable from a PS2 since it contains
capacitors which creates all kinds of issues.

The gain of the amplifier on the JPAC is currently set to 2.2 this is
controlled by the three 2.2K resistors around the amplifier. I have
modded my JPAC to use a gain of 3.3 instead but I have not yet tested
this.

rtw

[syntax_X]

[/quote]"If I use the low impedance VGA connector input on the Hantarex directly
with the LM1881 all is good "[/quote]

Are you using this with the jpac still? or are you using the psx to j-pac adaptor by itself?
im running a pentranic( i think thats what its called) and just have the standard jamma connecor to play with
Hantrarex run off 1 volt am i right?

[/quote]"The gain of the amplifier on the JPAC is currently set to 2.2 this is
controlled by the three 2.2K resistors around the amplifier. I have
modded my JPAC to use a gain of 3.3 instead but I have not yet tested
this" [/quote]

would like to know what the result is, i want to try the same for my psx to arcade monitor adaptor.
rtw

[syntax_X]

read thru your post again and figure your using the ultimarc PSX to j-pac adaptor directly with the Hantarex.

u'd have the Han set to 1 volt and it has a contrast pot right?

[rtw]

read thru your post again and figure your using the ultimarc PSX to j-pac adaptor directly with the Hantarex.

u'd have the Han set to 1 volt and it has a contrast pot right?

Yes I am using the LM1881 with cable connected directly to the Hantarex bypassing the video part of the JPAC.

I use the low impedance jumper on the Hantarex. The Hantarex has a contrast pot.

rtw

[syntax_X]

take a look at this rtw
http://www.gamesx.com/avpinouts/psxav.htm

im going to try it tomorrow after andy gives me the thumbs up, not sure if the amp and the way hes set up the lm1881n will have an adverse effects with the 220uf capacitor in each of the RGB lines.

[rtw]

take a look at this rtw
http://www.gamesx.com/avpinouts/psxav.htm

im going to try it tomorrow after andy gives me the thumbs up, not sure if the amp and the way hes set up the lm1881n will have an adverse effects with the 220uf capacitor in each of the RGB lines.

Can you show me picture of how you are going to connect it spcifically where are you going to put the capacitors ?

rtw

[syntax_X]

Im getting me ultimarc psx to arcade monitor adaptor(the one with the sync circut and amp)

Im connecting that to my screen by cutting the r g b sync and vid ground wires off my jamma harness and connecting the to the screw terminals on the amp( in there respective places.

I will be connecting the caps on the monitor side of the r, g and b lines.

Sorry rtw, no camera atm, but this explains pretty well.

Only thing i have to look out for i think is the orientation of the caps when adding them to the line

[syntax_X]

ok, got the caps today and heres how the story goes;


installed the caps after the ultimarc amp- nothing different
installed the caps before the ultimarc am- nothing different


Got the shits and thought to myself " I wonder if this amp is doing anything?, surely if i cut the rgb lines from the amp and connected them straight to the rgb on the cab monitor id be able to see if the pic was different and if it wasn't then the amp was doing squat (still using the chip for sync on the lm1881n)

what happens next goes against EVERYTHING i have read in all forums

The picture was perfect, no no, IS PERFECT!!!! what the hell is going on?
(its a little bright but i got the 220uf cap inline with rgb so ill take em off and see.)

so theres the fix you ultmarc freaks!

for the record the rgb lines on the amp are

Green=green
Orange=red
Blue=blue


Enjoy!!!!!

[emphatic]

Did you forward this information to Andy yet?

I think I understand what you've done here, but a photo of the modification would be awesome if you could borrow a camera or use your phone or something. I don't feel like cutting wires before I know exactly what I'm doing.

Edit: And this gives perfect picture for PSX as well as PS2, right?

Emph

[syntax_X]

im getting a set of non polarized caps today and installing them, ill take pics and send in a few hours, have forwarded to Andy, just waiting for a reply.

No, i haven't tested on ps1 yet, ill give it a go but i think the ps1 will need resistors on the rgb, then again may have to go caps with the way things have been going... ill give it a try and get back to ya

[elvis]

What a whole bunch of effort for something you could have achieved by buying a $10 SCART cable and hacking it up.

I connect all my consoles to arcade monitors via SCART cable hacks (failing that, I hijack RGB lines direct off the motherboards). It's not difficult at all. Ultimarc make some nice products, but their console connectors are not worth the money IMHO.

[syntax_X]

was using a pentranic 33 inch with all stickers and serials removed so i figure it needed to be amp'd.

[rtw]

syntax_x, could you please tell us what you did ?

I believe you are just getting the sync out of the LM1881 and then connecting the RGB directly to your non DSUB input ?

rtw

[syntax_X]

Thats right rtw,
effectivly just using a lm1881n chip to get sync and the rgb is connected directly to my non-dsub monitor.

I have put a polorized 16v 220uf cap on each of the rgb lines


The pic is alot clearer but white isnt as bright as id like it to be and black isnt as dark as id like it.

[elvis]

I have put a polorized 16v 220uf cap on each of the rgb lines

The pic is alot clearer but white isnt as bright as id like it to be and black isnt as dark as id like it.

Try a 75 ohm resistor between the capacitor and the console.

16V is also overkill for the cap. RGB out for SCART is only 5V, so a 10V cap is plenty.

[syntax_X]

Which side of the cap should i solder the resistor to?
should i connect the other side of the resistor to vid ground or the consoles ground?

What ifference do you think this will make?

Thanks for your input

[syntax_X]

Sweet the resistors fixed everything, also changed my 16v caps to 10v


so in the end my screen seems to work fine on the ps2 using a lm1881n chip for sync, and a 75 ohm resistor and 220uf 10v cap on each of the RGB lines connected directly to my monitor. (Resistors on the ps2 side of the cap)


END OF THREAD


Can't say thanks enough to everyone that helped out, you guys rock!

[antron]

the max voltage rating for the capacitor shouldn't matter, these signals are around 1V or less.

[rtw]

so in the end my screen seems to work fine on the ps2 using a lm1881n chip for sync, and a 75 ohm resistor and 220uf 10v cap on each of the RGB lines connected directly to my monitor. (Resistors on the ps2 side of the cap)

Could you please supply a simple asciimatic or an illustration ?

rtw

[rtw]

syntax_x sent me his schematic and I have uploaded it for you all to enjoy



rtw

[syntax_X]

thanks for that rtw

i should make note now that i was looking at a dreamcast adapter when i was drawing that pic so the colors of the wire on the left might be different but you only need blue green and orange.

[tsenzen]

is there anyway to achieve the same type of effect you guys have gotten but through the jamma harness



heres what i have:
J-PAC
JB-2 fingerboard
Universal AV to Arcade Monitor Adapter PCB (Ultimarc)
J21 cables
RGB modded consoles
5+ arcade cabinets

What im trying to do, is wire a 21pin switch box, into a jamma pinout (JB-2) so that way i can move it to any cabinet like a PCB board, and run 15khz consoles all day!!

so seeing the previous diagram, im wondering is there a posibble solution to have it actually work without the molex method? (thru the jamma harness) if so, how do i go about wiring this up?

any info will help thanks.

[Dave_K.]

Well it would seem all you need to do is follow the diagram posted by rtw, and rather than wiring directly to the monitor (on the right) you are wiring to your JB-2 fingerboard.

[charlie chong]

i take it the resistors and capacitators would work for boosting the colours on my homemade jamma saturn hack as well?? i would definitely use it more if i didn't have to mess with the monitor colours everytime i swap from a normal pcb.
thanks

[tsenzen]

so my issue was, that i couldnt figure out the J1 functions, thanks to andy himself, he sent me the diagram which im assuming is not available on the site?

anyways heres the layout:

[monty359]

syntax_x sent me his schematic and I have uploaded it for you all to enjoy



rtw

hi all i am new here, plz may i request can someone re-upload the picture of the schematic by syntax_x because the link no longer works so cannot view the schematic

[rtw]

hi all i am new here, plz may i request can someone re-upload the picture of the schematic by syntax_x because the link no longer works so cannot view the schematic

Sure

http://gameordie.com/shmups/ultimarc_ps2_adapter.jpg