Nintendo 64 (N64) RGB SCART video output using THS7374 amp

I recently bought an Open Source Scan Converter, or OSSC, primarily to make PlayStation 1 games look better on my display. After seeing how well RGB looked on the PS1, I had to try it on other consoles.

I already owned a Nintendo 64 and was using S-Video for video output, which is better than composite, but not great. When I installed the THS7374 amplifier into my SNES Jr. I bought an extra amplifier so I could do the same mod to my Nintendo 64. That’s what this guide covers, getting RGB SCART video output from the Nintendo 64.

What is RGB video?

N64 RGB video

In the United States most older video game consoles used either RF or composite video (coaxial cable like what you get cable TV out of, or the yellow/red/white cables) to output video onto a TV. These video output options are passable on a CRT television, but on a digital HDTV it can look quite bad.

Both RF and composite video is sent through a single cable (RF also sends audio over the same wire, while composite separates audio into two more wires). When all of the visual information is put into a single wire it can look fuzzy and dull, lacking the well defined edges and colors that you’d see with something like an emulator.

RGB improves video quality by using three separate wires for video, one for red, one for green, and one for blue. Each color gets its own wire, and each audio channel gets its own wire. With RGB video your console can output super clean video to your TV.

Why don’t people use RGB video?

SNES RGB SCART cable

In the United States RGB video was never available on regular televisions, so it was never an option. In Europe and Japan it was a common connector found on televisions. Europeans used the SCART connector, and the Japanese used the JP-21 connector.

Because televisions in the United States don’t have RGB video inputs, you will need to use a converter. There are cheap SCART to HDMI converters, as well as more expensive converters like the OSSC and Framemeister.

How do I get RGB video out of a Nintendo 64?

Most consoles were designed to be easily adaptable to a global market, so most consoles have the ability to output RGB video. In the case of the N64 early versions of the console had components inside to support RGB video, but they weren’t connected.

Serial numbers starting with NS1, NUJ1, or NUS-001 are generally all compatible with the basic RGB mods which rely on the N64 having built in (but disconnected) support for RGB. To confirm your system is compatible look for a chip labeled VDC-NUS or VDC-NUS A on your console’s board.

Once you’ve installed the mod in a compatible system you can connect your Nintendo 64 to a converter using a cable like this one.

Nintendo 64 RGB video output mod options

There are several ways to add RGB video back to the Nintendo 64.

  1. Using the built in Nintendo 64 RGB amplifier
    1. This is the cheapest option, since it only requires that you have wire and a few resistors.
    2. It’s also the hardest to install since you’ll need to solder wires directly to a chip, through a hole in the board, to the video output port.
    3. Video quality is very good.
  2. Using a THS7314 based amplifier
    1. This costs more money than using the built in amplifier.
    2. It is easier to install.
    3. Video quality isn’t quite as good as the built in RGB amplifier, or the THS7374.
  3. Using a THS7374 based amplifier
    1. This is the most expensive option.
    2. The installation process is the same as with the THS7314 board.
    3. Video quality is very good.
  4. Using a more advanced kits
    1. More advanced kits exist that can enable RGB video output on all Nintendo 64 models.
    2. Other kits exist that allow you to output HDMI video directly.
    3. Some of these kits allow you to process the video signal to remove a lot of the antialiasing blur from the console.

This post covers just the THS7374 based amplifier mod, but if you’d like to learn more about the other mods then you can check out this website.

A look at my THS7374 amplifier board

SNES RGB amplifier board assembled

Instead of buying prebuilt THS7374 based amplifier boards for about $30.00, I made my own boards for much less. The goal is to begin to sell these on my eBay store if there is enough interest.

Instead of starting from scratch I found an existing design on GitHub. In particular I went with the SNES_RGBAmp_wCSYNC version. I may eventually design my own board, but for now this works perfectly and is pretty flexible. As the name suggests the board was designed for the SNES, but I found that it also works with the Nintendo 64.

AllPCB SNES RGB amplifier PCB

I had my boards made at a Chinese company called AllPCB. They were able to get five boards made and sent to my house within a week for just $12.00. The PCB’s turned out very well. I chose 0.6mm thickness so that the boards would more easily fit underneath the console’s motherboards.

AllPCB SNES RGB amplifier PCB

Once the boards arrived I soldered all of the necessary components to them using a cheap hot air rework station, and solder paste. I ended up making three of the boards so I could mod my SNES, N64, and then have an extra left over.

AllPCB SNES RGB amplifier PCB

The end result is good. I applied a little too much solder paste to some of the pads, but nothing ended up bridging. It can be hard to get the right amount of paste out of the syringe.

SNES RGB amplifier board assembled

I ended up selling the third board on eBay and plan on making another larger batch in the near future. I’ll update this post with more information once they’re available.

THS7374 amplifier board installation into a Nintendo 64

As I said earlier, THS7374 based amplifiers are very easy to install into a Nintendo 64 It only requires soldering four wires to the console and the amplifier.

Nintendo 64 AV output port

Begin by locating the 12-pin Nintendo AV connector’s pins on the bottom of the N64 board. You’ll need to trim the plastic sticking through the two holes above the pins (12 and 2). Use something like side cutters. This is needed so that the amplifier board can sit more flush with the console’s board.

Nintendo 64 THS7374 amp board

With those pins trimmed, you can place the THS7374 amplifier board the AV pins like the picture above. I put some tape underneath the board just to prevent any possible contact with anything underneath.

Nintendo 64 RGB pin locations

Next locate the R, G, B, and CS vias on your board (labeled R10, R9, R8, and R16). The picture above shows where the pins are located, and below is a close up picture of them with pin labels. You’ll want to tin the vias using flux and solder. A concave shaped soldering iron tip is really useful for this.

Nintendo 64 RGB pins

Nintendo 64 CSYNC pin

Now you just need to connect everything. First solder the amplifier board to the AV pins, you’ll only need to solder the pins that have the annular ring around them. Then solder a short wire between each of the four pins. I used 30 AWG wire.

Nintendo 64 THS7374 amplifier installation

When you’re done it should look something like the picture above. Once you’ve finished soldering you can put your console back together.

Mod results

N64 RGB video

The video quality coming out of my Nintendo 64 with the THS7374 amplifier installed is very good, a significant improvement over the S-Video I was previously using. Above is a picture I took with my phone of Cruis’n USA through the OSSC.

I find the video quality of RGB with the Nintendo 64 to be almost as good as what you’d get when using a good Nintendo 64 emulator. Since I prefer playing games on original hardware this is exactly what I was looking for.

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