Extron MVX 84 & MVX 88 VGA-A matrix switcher review
Purpose
The Extron MVX line are professional video and audio routing devices that are used for assigning inputs to outputs in any configuration freely.
For us smashers, the main use of these devices is being able to re-route console and PC video to different monitors without needing to unplug any VGA connectors / re-wire cables.
I personally have used it for my main setup that consists of three CRT PC monitors that are fed video by two Gamecubes (with DAC VGA cables), one Wii (through Wii component cables and an
Extron CVC 200) and a number of PCs.
The MVX allowed for things like assigning a PC's video output to one of the monitor (to, say, watch a livestream) with the press of three buttons (input #, output #, enter).
Before I had the MVX, I was using a simple VGA switch and a couple of distribution amplifiers. To put it shortly, as soon as the number of video devices you want to switch between exceeds two and the number of displays exceeds one, the MVX handles things much better.
Other possible usage scenarios:
1. Routing a large number of console video and audio signals to a number of streaming / recording stations
2. Feeding a number of public info displays (for matches due to be played or showing the current livestream) whose content can be switched quickly and easily (VGA is still the go-to video signal for long distances)
Size, connectors, usage
The MVX line has rack format (44 cm wide and 24 cm deep). The 44-88 models have a height of 4.4 cm, the 128 model measures 9 cm and the 1212-1616 models 13.3 cm.
The video connectors used are D-Sub HD15 ("VGA"), which are standardized for RGBHV input, but also allow all other analog video inputs (RGBS, RGB with csync on any color channel, YPbPr / component video, S-Video, CVBS / Composite Video).
Note, however, that the MVX series does not feature signal transcoding. If you input CVBS, it will be output only as CVBS, never as RGBHV, for example.
Audio inputs on the 44-88 models have standard 3.5mm stereo unbalanced plugs. The inputs on the larger models and the outputs on all models are 5-pin headers with 3.5mm spacing that allow both unbalanced and balanced wiring. You can either buy pre-made connector cables from Extron (for about 15€ for just one cable) or produce them yourself by cutting audio cables, demantling them and screwing the copper into the connectors.
Some units come with the connectors included, some do not. In case yours misses them, here is where I bought fitting ports:
http://dhgate.com/product/productdi...pitch-3-5mm-screw-terminal&itemcode=136964930
Usage: A very nice feature of these is that they have very user-friendly instructions included on the back side of the unit, so you don't need an instruction manual.
To give you a basic idea of the usage process, here's a short description:
On power-on, the MVX will, after about two seconds of automatically self-testing (indicated by flashing LEDs), default to the input-output matrix configuration it used last time. To assign a new configuration, first click on the input you want to assign. This will make all output LEDs that currently output that port's video lighten up. By clicking on any of the output buttons, you'll toggle them on or off, with the corresponding LED directly indicating that change.
To confirm the new assignment, press enter.
Whenever you assign an input to an output that previously was displaying a different input, the previous input will keep outputting to all the outputs it was assigned to before, except the ones now assigned to the new input.
It is not possible to "mix" two inputs into one output.
By default, the LEDs for audio and video are both on. If you press the corresponding toggle, you can switch between audio+video mode, solo-audio mode and solo-video mode. The latter two allow assigning audio inputs two different outputs than the corresponding video outputs. For example, you can forward audio input 1 to audio output 1, but forward video input 1 to video output 2 (and video input 2 to video output 1).
To do so, you'd first press the toggle until only the video input lights up, and then do the normal process of video assigning (click on input 1, then on output 2, then on Enter).
There is also a per-input audio level mixer. By pressing the audio toggle button for about three seconds, it switches to a red LED that indicates audio setup. Pressing an input button will allow adjusting that input's audio signal strength with the ↑ and ↓ buttons.
Gamecube VGA cables will be processed directly and correctly. Wii VGA cables (those for 20$ that also have a PS3 input connector), due to their unclean sync signals, will not be processed correctly by the MVX if plugged in directly and simply show a black screen. By running the VGA cable through an Extron RGB interface before connecting it to the MVX, you can make sure the RGBHV signals are up to the MVX's standards. Alternatively, you can use higher quality YPbPr to RGBHV converters like the Extron CVC series.
Video quality and processing time
The video output is 100% of the input's quality, as far as I can tell visually (I don't have an oscilloscope yet, so I can't measure it currently). Anything else would be intolerable for professional video equipment that cost 2000-16000$ when new, so this was expected.
I have tried to measure the processing time, but it turned out that the equipment I have is insufficient. Extron lists a maximum propagation delay of
90+160 nanoseconds, and with 120 fps filming of two identical CRT monitors, one connected to a video signal that was routed to one MVX and the other one routed through two MVX units, all I was able to prove is that the lag is 0.3 milliseconds or less. I feel pretty sure that the sub-µs range specified by Extron is indeed correct. When I get an oscilloscope, I will hopefully be able to confirm this.
In any case, 0.3 ms is about one tenth of the input lag of the very fastest gaming LCDs out there, so even if the MVX has that much (which I doubt), you could run ten of them in succession without getting a significant amount of lag.
Power usage
The MVX is a professional device, not a consumer product. As such, it doesn’t have a standby mode, so you’ll have to turn off its power supply to ensure no power is drawn.
Regardless of whether video is being input or not, the MVX 84 draws 17 Watts and the MVX 88 draws 20 Watts. (Measured with a Voltcraft 3000.)
Extron gives power usage estimates of 30 Watts for the 44-128 models and 48 Watts for the 1212-1616 models, which I guess is assuming maximum audio volume and a full configuration (all inputs and outputs active).
Sources and availability
The 44-84 models are on Ebay quite often for low prices of 30-40$. The 88 models and upwards are a bit rarer, at least at affordable prices.
In my opinion and from following the Ebay auctions, these are the prices you should buy them at including shipping:
↓ Model \ Location → | USA | EU
Extron MVX 44 | 40$ | 60€
Extron MVX 48 / 84 | 60$ | 90€
Extron MVX 88 | 70$ | 110€
Extron MVX 128 | 90$ | 130€
Extron MVX 1212 | 100$ | 150€
Extron MVX 1616 | 150$ | 180€
I got my MVX 84 shipped to Europe for 90€ total and my MVX 88 for 110€ total, which where the cheapest offers in about three months each respectively.
About twice a year someone offers them for only about half the prices in this table. For example, I saw an MVX 1616 sold for 45$ once. If you see them for prices that low, I'd say buy them immediately.
Alternatives
There are other companies that produce matrix VGA switchers, for example Aten, StarTech and Lindy. However, from what I've seen so far, I don't think they are better buys than used Extron MVX switchers. So unless you can get one of the other brands for a really cheap price, I'd say keep looking for an Extron.
