In a previous thread
there was yet another discussion about the relative merits of various suppliers of video cables. So I'd like to break things down as cleanly as possible - first listing some technical topics of interest, and then a run-down of the known suppliers and their qualities. I also wanted to move away from the more "so and so says" type of discussions where people make recommendations or warnings without it being clear why various things are said, or whether they are relevant to buyers. This is definitely a work in progress - formatting is nearly unreadable and I might have some things plain wrong, as some of the topics are esoteric and technical. I expect to reorder and condense some things if there's demand for it. Finally, a word of warning: A lot of the suggestions one finds on these technical standards is meant for heavy-duty applications, and short cables lightly used in relatively low-bandwidth retrogaming use probably deliver great results without using the most expensive materials. We don't have a lot of data on this, and most of it is interpreted from the charts for more demanding uses, and also by individual users finding out what works nice with their equipment - which might have the exact same model number as yours, but perform slightly differently in their setup.SCART vs. BNC connectors:
I've heard a suggestion that the SCART plug type might not be optimal for RGBs (RGB+sync, the major type this thread covers). I'm not aware of hard data on retro gaming use, however. BNC and RCA are alternative connector styles. It seems that the major factors in making a choice are DEVICE SUPPORT and COST (or FLEXIBILITY). SCART is a quasi-standard for retrogaming, back from the days when 240p was next-gen and many manufacturers released RGBs cables using the connector. It's commonly used in video switches. You can also probably buy amazing video switches using BNC and RCA type plugs as well. It's possible to convert between BNC and RCA plug types with cheap adapters - again it's not known empirically what effect, if at all, they have on a video signal. In practice - this probably isn't a problem because we tend to connect these devices directly to a switch, at worst, so there are fewer chances for impedance mismatches to show up.
Any of SCART's disadvantages come from the plug's design for flexibility. While crosstalk or related problems aren't shown to be a huge problem, there are two widely used pinouts - ways of wiring up its connectors, known as EURO SCART and JP-21 - which have caused confusion and a lot of damage over the years due to people not labeling the connectors and making sure to only use them in correct devices. Unfortunately, you need
a SCART connector to connect to some devices. On the other hand, people who have exclusively devices that accept BNC or RCA connectors may find that SCART isn't useful for them; the price of going from two consoles to SCART connectors and then a common SCART to BNC connector is going to be higher than if those two consoles had cables wired straight for BNC, and the SCART plug is potentially unwieldy. On the other hand, once you've plugged in a SCART to BNC breakout, switching video cables is a bit easier than unscrewing BNC plugs (though I gotta say, I prefer the feel of BNC to SCART). Why are SCART plugs the standard for retrogaming cables? I imagine cost and simplicity in manufacturing is the major answer here, but I'd like more input from people making cables.
Some related links:50 Ohm vs 75 Ohm: BNC Connectors Explained (MilesTek Blog)
- One manufacturer's description of BNC plugs (we're interested in the 75 ohm type)Component Video Cables -- A Guide (Blue Jeans Cable)
- Mentions the effect of impedance in video.Is there Really a True 75 Ohm RCA Plug?Wire shielding:
The Blue Jeans Cable
company reproduces a handy table showing different types of cable, and provides estimates of relative quality. Shielding has been a point of contention, and understandably so. What's the point of a homegrown cable making operation trying to ape the Monster Cable-style mantra of "more is always better" if we are dealing with devices that have limited bandwidth requirements? Still there is at least one unknown we can guess at: Can high-quality displays show a difference when fed slightly improved video? What happens if we have longer or more complicated setups? What about upscalers and capture devices? And where does audio fit into this? I would love to see some data captures on this to see what are the practical limits on improving video quality by cable.Capacitors:
Depending on the cable you've bought, capacitors or resistors can both be found in video cables, handling the voltage (and therefore brightness) of video. Resistors aren't usually interesting, but capacitors have undergone constant development and refinement over the years. Additionally, many sources claim different performance or lifetime from different suppliers. Audiophiles often cite differences in sound quality when using different high-quality capacitors - however, this suggests looking at the quality of components in your gear, not the cable. Audio wires in RGBs cables, if present, aren't hooked up to a capacitor at all. Tom's Hardware recently posted an article
which makes some interesting claims, apparently informed by manufacturers of power supplies, about capacitor quality. It should be noted that a lot of the attention paid to capacitors - such as that in the article - is for their use in applications which are very difficult, whereas the capacitors in RGB cables have one of the easiest jobs a capacitor can have, even easier than those your old game console's 25-year-old capacitors have to deal with. The data on reliability is very uneven, as many people who do repair these aren't able to keep detailed records, and of course a capacitor carrying large charges blowing wide after being inside a very hot workstation PC case doesn't tell us much about whether a small capacitor from the same manufacturer will survive for a long time in a simple video cable. Finally, it seems that newer technology (such as polymer capacitors) performs very well regardless of supplier.
So, what's important here? Ideally, we'd like to buy good quality capacitors that won't have to be opened and messed with down the road. Some old first-party RGB cables (like official Nintendo RGB cables for the Super Famicom / SNES) have needed to be cleaned out and their caps replaced. It'd be ideal not to have this be required down the road. However, in terms of lifetime, who's to say that an "off-brand" capacitor in a cable won't last long enough? As far as I can tell, the major concern here is lifetime, not peformance. The flip side, of course, is cost. I would like to see what some realistic expectations of the cost pros and cons of various types are: For small cable makers, the cost of moving to a good electrolytic capacitor brand probably won't be so high, but what of moving to small polymers?Some makers of cables and what is known about them
There are a lot of posts here at Shmups, especially over the last year, about different makers. Of course it should be noted up front that if you have the skill and the parts, you can tailor a video cable to your own specifications. This list, therefore, is more about finding out what the relative qualities of the various makers are, and finding out what should be considered better value for the money (if not actually what constitutes a best practice). I'm not here to shame anybody, advertise, or warn people off from specific manufacturers; my opinion is that it is best if there are a variety of options available - some makers are closer and therefore cheaper for some users, and it also might not be bad if there were different cost options too. I hope to honestly portray each maker's statements on quality.
I should repeat something that I noted above about capacitors, except more clearly: We don't have any scientific data on the reliability of these manufacturers. Some suppliers may have quality issues in the past or future, without those being especially useful points of discussion when considering their present product. Many SCART plugs can be opened and inspected by users so you can fairly easily spot some problems to fix them. Aside from having good customer satisfaction, there also are different beliefs about what is required of a SCART table.Retro Computer Shock:
I don't know anything about this supplier other than that they exist and I was told they are worth a look.Retro Console Accessories:
This US-based maker has a presence on eBay and is widely respected for attention to quality and customer wishes. I have a SNES RGB cable from them and I think it performs well. An example of their components and construction, which looks very much like my cable, is found here
(thanks AdamBlue!) After users have talked about cable shielding and grounding, they've stated that these are important things. Since that last discussion, they've also mentioned to me that they're aware that capacitors are an interesting topic for some users - there might be more to add on this topic later!Retro Gaming Cables:
A UK-based maker of cables which has a website and an eBay store. It isn't clear to me how reliable their production quality is. I also don't have any of their products. An example of their components and construction is found here
(thanks again to AdamBlue). I also don't know if some criticisms of that cable won't apply to other makers. For a SCART to BNC breakout cable, RGC's website
states that "all ground pins are connected inside the SCART to avoid compatibility issues." It's not clear to me if this is standard practice for all their cables or not. What I do know is that within the last year or two they have reportedly said that heavy shielding on cables isn't necessary. However, please refer to "wire shielding" above and the table at the Blue Jeans Cable link. It's not clear to me what type of cable shielding any
maker uses, and it should also be considered that these cables are typically rather short, so their decision might be cost-effective.Other makers:
Shmups Forum user Daskrabs
is located in the US and has offered SCART to BNC breakout cables. I have one - it does what I expect. I know there are other people who have offered these as well.