RGB input switcher

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setiawan
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Joined: Thu Jan 14, 2021 3:10 am

RGB input switcher

Post by setiawan »

So presumably many of us here have RGB monitors with a single set of RGB inputs (e.g. RGBs BNC input on a PVM), yet we want to connect multiple inputs (e.g. consoles) to it.

I was planning on making my own mechanical/passive switch box that takes five sets of inputs, routing them through a rotary switch, and outputting via BNC connectors (+ 2xRCA for L/R audio). However, it looks like the project is getting a little pricey, so figured I'd double check here to see what everyone else's solution to this is.

What do you use to control input switching to your monitor? Is there a popular and cheap solution to this that everyone's using but I'm unaware of? Or are people constantly plugging/unplugging cables at the back of their monitor?
Dochartaigh
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Re: RGB input switcher

Post by Dochartaigh »

How many inputs/outputs do you want? What do the cables coming off your retro consoles end in? (most are using SCART cables because of availability and price, and not BNC). Do you plan on looping any converters/transcoders into the switch as well? (many of us use things like an Extron RGB box with 2-3 consoles, so doing things like looping that Extron RGB back into the switch so you don't ever have to change wires for that either ––everything can be routed via the switch–– is kinda amazing).

Here's a good run-down of some common SCART switches: https://www.retrorgb.com/scartswitches.html

For smaller setups (no looping ability), on the inexpensive side, people use things like a Bandridge 5:1 switch (5 inputs, 1 output) which i think I paid $50 for back in the day. At a quick glance of the above page it looks like the Otaku is around the same price (research – I've never used this one before).


For myself personally I use the ultimate, an Extron Crosspoint switcher, which uses BNC connectors and can route Composite, S-Video, YPbPr/Component, RGBS, RGsB, and RGBHV (VGA) + L/R Stereo Audio. Mine was $43,000.00 back in ~2005 (yes, $43K USD), now a mere $130 shipped off eBay lol (was actually free since a corner got dinged in shipping ;). --there's smaller models (12 inputs, 8 outputs) for ~$60 shipped on eBay right now. You can even control them via a touchscreen tablet or phone!

These DO require some adapters to be setup though since they use BNC's for video, and "Phoenix" connectors for audio. So if your console cables end in SCART, you need SCART to BNC adapters. If you use Left/Right RCA plugs for audio you'll need audio adapters to Phoenix plugs (people sell little adapters for maybe ~$2/each, or you can EASILY make your own). The Crosspoint also only takes csync - out of my 14x consoles I only needed sync strippers (to turn other types of sync into csync) for PS1 and PS2 - all others natively outputted csync so this really isn't a big worry.
setiawan
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Re: RGB input switcher

Post by setiawan »

Dochartaigh wrote:How many inputs/outputs do you want? What do the cables coming off your retro consoles end in?
Well the one I was planning to make was going to have five inputs: 3x RGBHV (BNC, and RCA for L/R), and 2x SCART. Currently I have three devices that I wanted to connect to the switch: a Raspberry Pi 4 (RGBHV), PS2 (component), and a Wii (currently composite, but was planning to get SCART cable for it).

The monitor is a JVC TM-H150 with an input card. The card is pretty versatile, with five connectors - RGBHV, but the first three double as YPbPr, and the fourth doubles as composite sync.

I just checked eBay, and it looks like there's an Extron Crosspoint Ultra 84 HVA available locally. Seems to be a bit pricier ($200AUD) than the offerings in the states, but I guess that's to be expected with regional rarity. I also just glossed over the manual for it, and wow is this thing feature-packed. Looks like it also doubles as web server so you can configure it over the network?!

This little snippet was also good to see: "The switchers do not alter the video signal in any way. The signal output by the switcher is in the same format as the input". Sounds like the inputs on this switcher should map pretty straightforwardly to the inputs on the JVC monitor, in regards to handling RGBHV/RGBs/component.

This switcher is clearly overkill for my needs, but I just might go for it. Will have to add some adapters like you mentioned (RCA->BNC, SCART->BNC, RCA->Phoenix), but it'll probably be a smaller headache than DIY'ing my own switch that would inevitably be of lower quality.
Dochartaigh wrote:The Crosspoint also only takes csync
I would think that the snippet I copied and pasted from the manual contradicts this, unless I'm misunderstanding something? The manual also explicitly states that the Ultra should be able to handle RGsB: "All models can also switch RGBS, RGsB, RsGsBs, HDTV, component video". I know that the Ultra has "ADSP", which is supposed have some kind of regenerative effect for the sync signal, but I'm not sure how else this affects compatibility. I don't think this will affect my use case, but would be good to clarify I think.
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maxtherabbit
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Re: RGB input switcher

Post by maxtherabbit »

+1 for the extron

The extron can only accept clean sync on the H or V input. It does work fine with sync-on-luma YPbPr or sync-on-green RGsB
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kitty666cats
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Re: RGB input switcher

Post by kitty666cats »

Two mechanical composite + L/R audio switchers super glued together = enough holes for RCA RGBS + stereo audio! EZPZ
Dochartaigh
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Re: RGB input switcher

Post by Dochartaigh »

setiawan wrote:I just checked eBay, and it looks like there's an Extron Crosspoint Ultra 84 HVA available locally. Seems to be a bit pricier ($200AUD) than the offerings in the states, but I guess that's to be expected with regional rarity. I also just glossed over the manual for it, and wow is this thing feature-packed. Looks like it also doubles as web server so you can configure it over the network?!
Yeah, sadly they seem to be more expensive elsewhere in the world unfortunately. I would try to find a 128 (12x8) version instead since those have the same case size as the 8x4 version (so you have LOTS of room to grow). And like you saw you want the "HVA" version so it comes with audio (many don't have that). I also stay with the newer version which has the white (NOT black) buttons on it - that's the version I wrote the code for the touchscreen to work on.

There's also VGA/DB15 versions of these Extron switchers which are quite a bit smaller. I've never owned one (so can't tell you much, so research) but people commonly use cheap DB15 to 5x BNC breakout dongles on the back to get BNC, then you basically have the same RGBHV the BNC versions have with the same functionality (don't know about using touchscreen remote on those though).



setiawan wrote:
Dochartaigh wrote:The Crosspoint also only takes csync
I would think that the snippet I copied and pasted from the manual contradicts this, unless I'm misunderstanding something? The manual also explicitly states that the Ultra should be able to handle RGsB: "All models can also switch RGBS, RGsB, RsGsBs, HDTV, component video". I know that the Ultra has "ADSP", which is supposed have some kind of regenerative effect for the sync signal, but I'm not sure how else this affects compatibility. I don't think this will affect my use case, but would be good to clarify I think.
Like maxtherabbit posted, it's only for the sync lines of RGBS where it needs clean sync (the "H" is most commonly used for the sync of RGBS). Composite and Component are fine since those hookup to the R/G/B lines.

For any changes the Crosspoint makes, it will raise the voltage on the H and V output lines, but if you're using a professional CRT you'll be fine (this voltage is a bit much for consumer CRT's and some other consumer devices and can damage them over time they say).
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matt
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Re: RGB input switcher

Post by matt »

+1 for Extron as well. I have two of them; they are great and were really cheap.

If you just want a basic switcher with one output, they made a 6 position VGA+audio unit that's small and usually inexpensive. Of course this means you may have to make some adapter cables and the caveat about they only working with clean sync signals also applies.
setiawan
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Re: RGB input switcher

Post by setiawan »

Thanks for all the input guys! The main thing that has been bothering me about the idea of getting a Crosspoint is that it's quite a behemoth. My setup is mainly desk-based, so space is a bit of a premium. It would be less of a concern if this was something I was going to put in a lounge, and had the space for an AV rack or entertainment unit.

Looking at the range of devices from Extron, I'm starting to lean more towards their SW series (with RGBHV + audio). It has less features (mainly that it only has one output, and doesn't have all the features associated with outputting to multiple displays), but I think that should be fine for me. It's also cheaper and smaller which is nice. The disappointing thing is that I'll probably have to go with the SW4 (four input version), as the SW6 appears to be pretty rare. I can imagine that only four inputs may leave a bit to be desired in the future, but hey, it's a balancing act. If circumstances change in the future (and the prices of these Extron devices don't skyrocket), I'll probably reconsider the Crosspoint.

Having said that, anyone have any experience with these SW series RGBHV A devices? I assume that they are only able to handle a clean sync signal as well? I.e. that I'd have to use sync strippers on the input of devices that output their sync signal with other information (e.g. PS1, PS2)?

In regards to the Crosspoint, I assume they can channel different inputs to different outputs simultaneously? E.g. Input1->Output1 + Input2->Output2 at the same time? If so, wouldn't people be able to get around the sync problem by putting the sync signal on one of the RGB sockets of a different input/output? It would effectively divide your outputs by half I guess, but it's the first thing that came to mind. Picture for demonstration:

Image
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maxtherabbit
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Re: RGB input switcher

Post by maxtherabbit »

I use a MVX VGA 84 A. One rack unit 8x4 matrix. Works flawlessly. Supports IR control too
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