SNES PAL 1Chip with RGB bypass VGP 4.1b

[dino112]

Hi,

I’m planning to mod a SNES PAL 1Chip with VGP 4.1b RGB bypass (https://videogameperfection.com/products/nintendo-rgb-bypass-amp-revision-4-1b-vgp/) and I have a few questions if you could help me out with.

Question 1: R18 resistor

In mod instructions it says:

Because the amp has been configured for use with an NTSC cable, if you have a PAL console and your RGB cable uses composite video for sync then you will need to select the “I have a PAL SNES” option above and replace R18 on the SNES main board with a 75 ohm 0805 package resistor that will be provided with your order.

I’m confused about replacing R18. It’s a 1chip PAL console, the csync will be taken from the mod board, multiav pin 3 freed and used with an NTSC cable (with 470 ohm resistor). PAL cable won’t be used, so not sure in what case R18 should be replaced? I didn’t find mention of R18 anywhere else, only on the VGP SNES mod page?

Question 2: RGB lines

I noticed a mod with same board in which RGB connections are made to resistors R6-R8, instead to vias on the right side. Does this mean that connections aren’t direct but through those resistors? I noticed on other mod e.g. Voultars that RGB lines are directly connected.
Here is picture from that mod and a tweet:

https://twitter.com/A3rgan/status/1586686047907446784

Question 3: C44-C47 capacitors

I understand that this mod is made universal to support SNES 1CHIP-1/2/3 and SNES Mini. Mini and 1CHIP-03 don’t have these capacitors and 1CHIP-01/02 have so in instructions you mention that these capacitors should be removed from the main board. I would prefer to be less destructive to the main board, in case a revert is needed. Do you think it would make sense to leave those capacitors on the main board and remove equivalent capacitors on the mod board? It seems that would be capacitors C7 to C10?

Thanks!

• This topic was modified 2 years, 7 months ago by dino112.

[BuckoA51]

You only need to replace R18 if both of these things are true.

1) PAL SNES console
2) You are using a RGB cable that has composite video for sync.

Seems like you intend to use composite sync so you can skip that part.

[TheCorfiot]

Hello There

As replied above, you can ignore R18 being replaced due to the cable you plan to use.

Regarding the RGB lines, it is your call tbh the vias alongside the resistors are indeed tracked to them.
some people shy away from soldering direct to VIA’s as they can be delicate, but if you use thin enough, eg AWG30 kynar you will be fine….

If a brightness mod is required then installers will take the rgb outs from the chip resistors and leave the vias free in order to hook up the pull down resistors required for the brightness mod

Regarding Q3, the capacitors should really be removed

• This reply was modified 2 years, 7 months ago by TheCorfiot.

[dino112]

@BuckoA51, @TheCorfiot

Thanks for the help! I was confused about composite video for sync vs composite sync, all is clear now.

btw. good read od the sync types if somebody else get confused about this:

https://www.retrogamingcables.co.uk/composite-video-vs-composite-sync

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