Neopass module for NeoGeo AES : the easy way to perform AES video bypass :-)

I can’t help but recommend, to anyone interested in @Nic034 ’s product, to support this project: it’s a small modkit that greatly simplifies the process and ensures a fantastic image quality result. There are many ways to carry out this operation, but this one—both on paper and in practice—is very likely the best.
Thanks a lot mate for this kind feedback and support for this product 😃
Nico
 
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Hello

Here are some photos sent by a few kit installers :-)

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What kind of CRT is in the last few pics?
 
As far as I know, the first one is a Sony Trinitron. For the second one, I have no information except that the screen was slightly curved.
 
Hi everyone, I hope you’re all doing well. For those who ordered the module from the shop, if you’re having any delivery issues or if you haven’t received the module yet (thanks trump) — especially those of you in the United States, you can contact me if needed. Nicolas
 
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Bought and installed 3 more units from Nico, and the result is outstanding as always!
If you own an AES and haven’t installed this yet, you’re seriously missing out.
 
Hello

Happy new year to all :-)
Some contact pictures using OSSC and 6x scaling (wow 😎) enjoy with #neopass module

Enjoy 😉

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This is fantastic, but I hope one day you can make a version 2 that has amazing composite output as well!
Not planned at all, but who know ;-)

possible without cutting tracks on 3-3,3-4 but need to cut av pin 3 track and 3-5/3-6 (av pin 3+7 are bridged..).
 
Dear friends,

Bad news: shipments to the USA from France are blocked as of February 26 due to the new Trump customs duties (changes taking effect in early March 2026).
There will be no shipments to the USA for a few weeks.

Refunds are currently being processed for my U.S. customers.
Please try again later :)

Sorry for the inconvenience!
#Customs #Shipping #USA
www.nic034.fr
 
Hello

I am interested in doing this mod instead of using pots and dial until the signal is ok like retrosix guide, his method is fantastic but i think this one is cheap and doable easier.

Anyway, I have 3-6 version and I am using this cable: https://www.retrogamingcables.co.uk/neo-geo/aes/NEO-GEO-AES-RGB-SCART-CABLE-STEREO-SOUND

I want to retain composite even though I am not using it, for completion.

I read the comments and this is the conclusion I arrived at:

1- do the mod as you mentioned in the guide, now I have clean RGB.
2- wire csync as your guide suggests. Now pin 7 should have the proper csync from your mod.
3- cut av pin 3 and pin 7 bridge if it exists, your post says it does for 3-6. now I have pin 7 with clean csync while pin 3 is nothing.
4- grab 470u cap and 75 ohms resistor, hook cap positive leg to CXA pin 20, cap negative pin to 75 ohm resistor, then the other leg via a wire to av pin 3.

Is this correct?
 
Hello

Keep in mind that the main purpose of my module is not to preserve composite video at all costs, but to encourage people to play in RGB and get the best possible image quality. SNK NeoGeo games were not originally designed for composite video at all, they were made for RGB (the MVS runs in RGB). Composite was only introduced as a workaround because SCART wasn’t mainly available in the US, and during certain periods in Europe as well. Play neogeo game in composite is like eating fastfoot in a palace ;-)

On the 3-6, the sync is only composite. If you check the schematic below, you will see that pin 3 and 7 have « video » (the composite coming from CXA1145p tru caps.

You list seems to be ok for me :-)

The AES revisions 3-6 also suffer from numerous problems tied to the RGB lines feeding into the CXA1145P encoder and being buffered/processed through it. I strongly discourage using the RGB output coming straight from the encoder itself — the signals are heavily degraded (jailbars, washed-out colors, alternating noise.., etc.).

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Hello

thanks for your fast response.

I cut the 3 traces which causes jailbars and noise, the picture is very good in my crt via rgb scart converted to component. However, I am about to recap my aes and would like to make all available enhancements once and for all.

i won't be using composite but still nice to have it complete package, and as i listed above it does not require much. the cap kit will include 4 of those caps which i won't be using due to using your board. so I can use one of them for the composite and maybe another one as an extra main filter cap for the entire 9v input.

If I have composite now, that means the cable has LM1881 sync stripper inside right? seems to be the case according to available info. with cutting the 3 traces it produces clean image now... your mod will make it better.

so your mod takes the signals before entering the encoder, and level shift them? I suggest making another version which is like retrosix method of modifying input stage to cxa which makes it universal and easier but that is up to you in the future.

So you confirm my suggestion above is all correct? I need to verify before buying.

and if done, the pin 3 will have composite signal coming from cxa but using the original rgb signal not your enhanced one? i assumed that your mod does not adjust the input rgb to cxa.

i appreciate your detailed explanation... thanks in advance!
 
If you’ve now the composite (and already perform the RGB fix on 3-6) it due to composite signal on pin 7 for me coming for pin 20 CXA (which receive the RGB signals in input)

I don’t want to use the CXA encoder at all for RGB, this chip don’t be needed for RGB but only used to generate correct sync (which I use) and composite video (which i remove) ;-)

On the 3-6, the pin 3 and 7 is for me bridged (in my mind) like the 3-5 schematics show in GitHub. Keep in mind that the composite support is linked to the cable used (pin 3, or pin 7 or both) and I cannot guarantee this will work in all condition using original composite cable.

My mod remove completely the RGB input to CXA (as the 6.8k are removed). if you install it, you will not have composite video at all on the pin 20 output on the CXA (I think)

as explain the goal of my solution is to bypass the CXA encoder and remove the composite video. You cannot use this mod « as is » and route the composite to av port.

You need to manually perform the bypass, route the sync and route the composite, or keep RGB fix, route the sync and de composite :-)
 
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Hello

well, this seems new info compared to earlier comments. some people mentioned the ability to route the composite.

this thread explains it a bit: https://consolemods.org/wiki/Neo_Geo:RGB_Bypass_Mod_(AES)

restoring composite is exactly as I explained but here they are using the ferrite bead or rather keep it, while disconnect the trace bridging pin 3 with pin 7 at ferrite bead stage.

I am checking 2 available schematics, one you mentioned with ferrite bead stage shorted for pin 3 and 7, and one which they are not.

you are removing the 6.8k resistors which cuts rgb input to cxa, this will make it not output rgb and so won't output composite.

however, since you are not using the same output traces and pads (caps) it uses, and you fully disconnect the rgb out caps from it... this makes its rgb out not reaching the av output connector and not affecting your mod.

which begs the question: why remove the 6.8k resistors to begin with? I mean keeping them will keep feeding rgb in signals to cxa chip and it will output rgb (won't be passed) and composite (won't be passed) while then I can use my method to re-route composite successfully.... Still your mod will get the clean rgb input it wants and outputs the clean rgb you designed it for.

^
how about this?

unless keeping 6.8k resistors actually negatively affects your mod which I do not see it a valid assumption, but you know best.
 
Hello

well, this seems new info compared to earlier comments. some people mentioned the ability to route the composite.

this thread explains it a bit: https://consolemods.org/wiki/Neo_Geo:RGB_Bypass_Mod_(AES)

restoring composite is exactly as I explained but here they are using the ferrite bead or rather keep it, while disconnect the trace bridging pin 3 with pin 7 at ferrite bead stage.

I am checking 2 available schematics, one you mentioned with ferrite bead stage shorted for pin 3 and 7, and one which they are not.

you are removing the 6.8k resistors which cuts rgb input to cxa, this will make it not output rgb and so won't output composite.

however, since you are not using the same output traces and pads (caps) it uses, and you fully disconnect the rgb out caps from it... this makes its rgb out not reaching the av output connector and not affecting your mod.

which begs the question: why remove the 6.8k resistors to begin with? I mean keeping them will keep feeding rgb in signals to cxa chip and it will output rgb (won't be passed) and composite (won't be passed) while then I can use my method to re-route composite successfully.... Still your mod will get the clean rgb input it wants and outputs the clean rgb you designed it for.

^
how about this?

unless keeping 6.8k resistors actually negatively affects your mod which I do not see it a valid assumption, but you know best.

The proper way to perform a clean RGB bypass is to keep the RGB signals intact coming from the NEO-B1, palette rams and gates before feeding into the CXA1145p

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As the main goal project is to have the cleanest RGB possible and absolute avoid to feed the CXA with it (not to have composite, not to keep it in any way or to feed the CXA with RGB), i read many papers and way to do this, following the solutions already successfully tested by others (brought/made a few improvements adding output caps for example, taking a lot of time in testing / R&D). I wasn’t necessarily trying to reinvent the wheel :-)

But it will be interesting to test for testing purpose if you’ve time.

If you let the 6.8k in place, perhaps you will have side effect due to split signal on both side / or due to the resistors after etc...to be clear, I’vent tried this to be honest (because I don’t need, for me composite is the badest video signal ever possible 😂), if you need, you will have to test on your side sorry ;-)

Honestly, for me, it was a complete waste of time testing something like that when I never wanted to keep the composite in the first place.

I can only bring support to my product and solutions what I’ve tested ;-) I understand your need, though.

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Hello

can you inform me at least what is the way I can test and verify the signal? I mean use oscilloscope to check if it is 0.7v p-p after everything at output pin? this should be clear to you since you designed the board to attain certain level on the output.

However, circuit wise, the input to your mod should not get affected by the resistors and CXA. since you and CXA taking input from the same node = in parallel. If CXA circuit some-how in series of your circuit or terminating the voltage input...etc then it would interfere.

You mentioned taking signal before feeding to CXA which is still the case here. The only downside that could happen is if the signal is driving a heavy load which will reduce its voltage, but this is not the case here as CXA is just an amplifier which does not output the signal itself but uses it as a reference and uses its own power supply to generate the output signal.

I can invest time into doing this but i appreciate informing me about the way to measure the correct output signal and how much it should be.
 
Hello

can you inform me at least what is the way I can test and verify the signal? I mean use oscilloscope to check if it is 0.7v p-p after everything at output pin? this should be clear to you since you designed the board to attain certain level on the output.

However, circuit wise, the input to your mod should not get affected by the resistors and CXA. since you and CXA taking input from the same node = in parallel. If CXA circuit some-how in series of your circuit or terminating the voltage input...etc then it would interfere.

You mentioned taking signal before feeding to CXA which is still the case here. The only downside that could happen is if the signal is driving a heavy load which will reduce its voltage, but this is not the case here as CXA is just an amplifier which does not output the signal itself but uses it as a reference and uses its own power supply to generate the output signal.

I can invest time into doing this but i appreciate informing me about the way to measure the correct output signal and how much it should be.

I don’t understand what you want to test or mesure in fact related to composite signal. Can you develop ?
 
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