Shiro Discord member Moosetrack spotted a relatively inexpensive (~$20) RGB SCART to YPbPr component video converter available from various sellers on AliExpress like this one.
I decided to take a chance, picked one up, and ran a few technical tests to help provide info for others craving creamy 3D graphics over component video.
Overall, the RGB SCART to YPbPr component video converter appeared to work quite well, producing relatively clean lag-free video for a low price.
For the technically interested, check out additional technical details below.
Connections used
Sync-on-Luma RGB SCART cables from a Saturn and PlayStation were each connected to the converter (one at a time), with the YPbPr component video output from the converter connected to a CRT TV with YPbPr component video input.
Other cables types (e.g., Sync-on-Composite, Csync, etc.) were not tested, although it may be the case that Sync-on-Composite and composite sync cables would work similarly (the converter uses an LM1881 sync separator).
Latency
Latency was measured with an available Logic Analyzer in analog oscilloscope mode (Saleae Logic 8) at the highest (10 megasamples per second) sampling rate. While a faster and higher quality scope would provide more accurate measurement data, the Logic 8 was the scope on-hand.
The sync line on the SCART connector and the Luma (Y) output from the converter were monitored on the scope. The PlayStation BIOS boot screen was used (a white video display, to enable easy signal identification on the scope). Measurement was taken between the input and output signals, at the negative edge of the horizontal sync pulse at the start of the first white line after vertical sync. The measured delta was approximately 100 to 200 nanoseconds, so a latency imperceptible to the human eye.
Power consumption
The converter has a USB Type C connector (cable provided), with which a typical USB Type A power brick (or Type C) could be used. Using a USB power meter, 70mA of current was measured at the DC output of the 5v USB power brick used to power the converter. This is general quite modest power consumption.
Audio
Audio is a simple signal passthrough (verified with a continuity tester with the SCART audio lines and the RCA audio outputs of the converter), so no additional processing observed.
Chips at a glance
The following integrated circuits were observed on the converter. The chip labels were taken at face value (i.e., no attempt was made to identify counterfeit IC status).
- LM1881 (sync separator)
- 7316 (believed to be a Texas Instruments THS7316 video amp)
- BA7230LS (video encoder, likely the color space converter used to convert between RGB to YPbPr)
- (74)LS86A (XOR, which is assumed to be used for conversion from VGA horizontal and vertical sync)
Video resolutions used/observed
The Playstation BIOS boot screen used for latency measurement is 480i.
The converter was also used with a couple of Saturn essentials: Virtua Fighter 2 (480i) and Nights into Dreams (240p).
No resolution conversion was observed (the converter performed only basic colorspace conversion).
Not assessed in depth
Neither color analysis nor calibration was performed, but the converter does have three potentiometers, which enable tuning of color.
The converter’s VGA input was not tested.
A bit more about video connections
Optimizing video quality for classic gaming is a very deep rabbit hole. There are countless options in the form of connections, upscalers, and converters over a wide range of budgets. Add nostalgia, subjective opinion, and sensitivity to the mix, and you have a recipe for confusion for a newcomer.
One option that many classic gamers enjoy is experiencing their consoles connected to a consumer grade CRT TV. If you have the space for it, it can be a great option for a lag-free gaming experience that’s relatively inexpensive.
The Saturn provides several analog video output options through the use of different cables:
- Composite (the “yellow” RCA connection that many remember using in the pre-HDTV era), which combines all video information (brightness, color, and synchronization) into a single signal.
- S-Video (mini DIN style round connector), which separates the video information into two signals: Luma (Y, containing brightness information and synchronization) and Chrominance (C, color information).
- RGBs (SCART connector), which separates the video information into four signals: Red (R), Green (G), Blue (B), and synchronization (s).
In general, separating the video information into separate signals helps prevent those signals from interfering with each other, enabling a sharper picture with more vibrant color representation.
While many Europeans enjoyed the ability to connect their Saturn to their TV using the higher quality SCART connector, North American Saturn owners typically had fewer options, in the form of composite or, less commonly, S-Video.
Some later model North American CRT TVs were equipped with the option to use YPbPr component video (consisting of green, red, and blue RCA connectors). YPbPr component video is similar to RGBs in that it also separates the video information into several signal lines (more than in composite and S-Video). The clarity of YPbPr component video rivals that of RGBs, but there’s a catch: Classic consoles such as the Saturn do not have native YPbPR output.
For a Saturn gamer fiending for the cleanest video the console and component-video-equipped TV have to offer, they’ll need to convert the console’s RGB signals to YPbPr component video digestible by their TV.
While many HDTVs also include YPbPr component video inputs, all HDTVs include some lag (additional time delay between the console’s video output and the content displayed on the TV). Gamers interested in gaming on their HDTV may be interested in exploring retro-gaming-focused upscaler options. There are many such great options accepting RGB SCART connections directly (e.g. RetroTink products), and providing digital video output (e.g., HDMI).
TR has been a member of SHIRO!’s community for about a year. The Saturn was their first console, and joining this community has gotten them excited about it all over again.
Hi, thank you very much for the information.
I currently own two of these units because I’m from South America, and here the closest thing we usually get to RGB is YPbPr. I use this transcoder with Sega Genesis, Sega Dreamcast, Saturn, and SNES.
Recently I bought a MiSTer FPGA, and these only have VGA output, which can be used as VGA/VGA or VGA-to-component directly (which is how I’m using it now). A friend of mine also bought a MiSTer and asked me if there was any way to use the VGA or VGA to component cable to get composite video.
I know there are people who would like to use this device for composite output, so I wondered if that would be possible. Short answer: no. Long answer: it can be modded.
Unfortunately, this version is not wired to output composite video, and I haven’t seen any version of this exact model that is. However, the board can be modded fairly easily because, as you correctly pointed out, those components are capable of generating an NTSC signal (IMPORTANT: NTSC ONLY, not PAL). The BA7230LS converts RGB to NTSC without any issues, but the composite output pin is simply not wired.
According to the BA7230LS datasheet, one of the pins near the edge of the chip is the composite video output, but it requires adding a resistor and a capacitor. In the end, I didn’t do the modification because I don’t need it, but I couldn’t find this information documented anywhere.
Of course, this mod doesn’t have many practical uses, except for very specific cases, such as using a MiSTer or a PC and needing to connect it to a TV that only has composite input. I ended up researching this because I was asked how to get composite video from a MiSTer FPGA, which already outputs RGB through SCART using VGA (I know there are other converters, but if you already have this one, it can potentially be reused)
I also remember reading a review of one of these transcoders that did include a composite output option. After searching everywhere, I couldn’t find anyone confirming it. In the end, it turned out to be a very similar Chinese transcoder, smaller and black, which i have and it indeed include a composite switch. However, it is no longer manufactured or sold, and it also didn’t include a VGA input, so I assume they later redesigned the product and split it into different versions.
Finally, I’d like to mention that I own both this version and the small black version I mentioned above, and on the black one the colors are much brighter and more saturated. Supposedly it is missing a resistor or something similar and can also be modded (on that smaller black version).
That’s all. Thanks again for the review. If you discover any other use for this device, please share it.
Best regards.