MT-ViKI MT-431AV 4 Way Switch Review

[differenceclouds]

Were the inputs 2 - 4 unconnected? If so, I would expect a lower crosstalk level by connecting them to a low impedance output/termination.

Yeah I have this model and I found that as long as the inputs are connected to something there was no (audible) crosstalk issue. Why would you switch to an input you aren't using? It could be a poor mute switch I guess.

 

[Barrelhouse Solly]

l have a similar switch I used in my bedroom system when I was using a ~2000 HK receiver. It seemed to work OK. I'm currently using a 3 way rotary switch--3 in, 1 out--that I bought at Fry's in the early '90s. I like it for the nostalgic appearance. It looks like something from Lafayette or RS. I use it on the second analog input on my current amp mostly when I watch video on my tablet. Using either, I've never noticed audible crosstalk. That doesn't mean that there might be a significant amount that's measurable.

 

[Joe Smith]

I use these exact ones for instances where I need switchable inputs, have found them to be perfectly satisfactory for normal listening. In my workroom system, it currently allows me to bring in my DAC one one circuit, a tape deck on the other. I also use in main downstairs system with an older Yamaha receiver where I don't have enough inputs for everything I use.

Until there are more simple, inexpensive 2-3 input passive pre's available, this is a cheap and simple way to go if you don't need in-line volume control.

I never use with multiple sources playing at one time, it is strictly for convenience so I don't have to replug the RCAs if I have multiple sources in a setup with one of my amps.

 

[DWPress]

I'm missing high-end stuff being measured lately. I mean very expensive stuff like used to be measured here like ps audio, totaldac. It was such fun

I kinda like all these little cheap device reviews, occasionally there's a gem that serves a purpose. Transparent functionality in audio doesn't have to equate to $$$$.

 

[craigenputtock]

This is a review and detailed measurements of the MT-ViKI MT-431AV 4-way audio and composite video passive switch. It is on kind loan from a member and costs US $11 on Amazon:
View attachment 340474
I wouldn't be able to give you time of day for $11 (including shipping no less!) yet we have a metal box here with four nice/solid feeling selector switches. Back panel brings back horrible memories though:
View attachment 340475
Composite video! Man, those were the days of horrible picture quality with color decoder errors and lousy resolution. I assume no one uses the video feature in this day and age so let's quickly test the rca switching capability.

Audio Switcher Measurements
Let's start by measuring the performance of the Audio Precision APx555 while looping back internally with 2 volts out:
View attachment 340476
Immeasurable distortion and SINAD limited by noise. Let's now route the signal through a 6 foot switch to the MT-431AV and then back to analyzer using 3 foot cable:

View attachment 340477
There is essentially no impact. We do have a bit more 60 Hz which is a given due to much longer shield path of unbalanced RCA connection (I could reduce it a bit but why bother).

Since this is a passive device, we can assume transparency in all the other measurements except crosstalk from unselected input. This can be a serious problem. I have switchers where you can easily hear what is playing on the unselected input. So let's test for that:
View attachment 340478

The dashed blue line as 0 is the frequency response when the input is selected. The other curves below it are with the same setup but with inputs 2 through 4 selected instead of 1. We see that input 3 is worse than the other two but all three suffer from capacitance that is cross coupling the inputs. The higher the frequency, the worse. Input 3 gets as bad as -32 dB! This could be due to switch itself, wiring or both.

Conclusions
What can you expect for $11? Maybe this is all you can. I like to think though if any attempt was made at measuring, we could do better.

I can't recommend the MT-ViKI MT-431AV. There has to be a better switcher out there...

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Can anyone recommend a good speaker switcher? also an amp switcher?

 

[Blumlein 88]

Were the inputs 2 - 4 unconnected? If so, I would expect a lower crosstalk level by connecting them to a low impedance output/termination.

I seem to recall old Radioshack tape switch boxes (for adding switching for 4 tape inputs when your receiver or pre only had one) they shorted unused inputs with a 1 k ohm resistor presumably to reduce crosstalk.

 

[bgravato]

Which makes me wonder can one use the output as an input for four selectable outputs?

You probably can.
Some of these are 'reversible' : https://www.audiophonics.fr/en/source-selectors-c-599.html

It's a passive switch... there's no reason why it wouldn't work "both ways". It's just some pieces of metal making connections... electrons can flow in either direction... there is no such thing as one-way passive switches/connectors/cables.

 

[bgravato]

In case there still are dinosaurs using RCA composite video these days... IDK.

But for the price, the passive preamp is acceptable. Thanks, @amirm

Probably barely no one and that's likely why they're so cheap...

I have a similar passive switch (3-way) by SkyTronic that I bought for similar price, quite a few years ago from Amazon... It has only R/L pairs, no video.
I tried to find a similar one for a friend the other day and the ones with 3 connectors (R/L+video) were surprisingly much cheaper than the ones with only R/L. I'm guessing many people looking for audio switches will not buy these perhaps because they see the video connector and think it's no good for just audio... hence probably making these kind of "old stocks" that they're trying to get rid of?

 

[DrZingo]

Perhaps old "Retro" video games.

And Laserdisc players.

 

[Blumlein 88]

You could use the video connector for 3 channels. LRC for front of a surround set up. Use a second one for rear channels and a sub if it's 5.1 surround

 

[AuricGoldfinger]

What kind of switches would result in the level of crosstalk that this device suffers from?

 

[Hayabusa]

What kind of switches would result in the level of crosstalk that this device suffers from?

It's most likely the wiring inside. If you measure with open inputs at a high impedance, any capacitance will give you major crosstalk.
It should have been measure with sources connected. Who listens to open inputs?

 

[F1308]

US $11 you said?

Where might have possibly gone the nice people of the good old school that brought prices so correctly along the past years?

US $11 is not a price.
It is a number.

Prices are meant to be US $10.99 or may be US $10.95.

It is about to strike six here, CET.

 

[JohnBooty]

I really appreciate this review. I definitely use these little passive switchers. I feel like every single audio setup I have has one less audio input than necessary. If there are five inputs I need six. If there is one then I need two.

In case there still are dinosaurs using RCA composite video these days... IDK.

There's a small but dedicated army of people who use and/or restore CRT TVs for retro gaming purposes. We appreciate such devices still being available.

There are some legit technical reasons why CRTs are preferable for older game systems; it's not just fetishizing an old technology like 8-tracks or something.

 

[wwenze]

It's a passive switch... there's no reason why it wouldn't work "both ways". It's just some pieces of metal making connections... electrons can flow in either direction... there is no such thing as one-way passive switches/connectors/cables.

With a crosstalk on open connection this bad maybe it cannot work as a 1-in-4-out.

The reason we say connecting to a source will reduce crosstalk is because sources have low output impedance so it will suck away all the unwanted noise. Load/receivers however are generally high input impedance. Like 100k or whatever, who knows how high that is with regards to calculation but let's just say it's high.

So with an isolation of only -30dB at certain frequencies, if you use it as a 1-to-4 switcher, the unselected outputs will still be playing sound at -30dB... That's a pretty bad switch.

 

[BlackTalon]

Perhaps old "Retro" video games.

My first thought as well, especially since my son acquired three vintage consoles over the holidays that all have composite video, and the TV only has a single input (the composite-to-HDMI device I bought doesn't seem to work...).

 

[bgravato]

With a crosstalk on open connection this bad maybe it cannot work as a 1-in-4-out.

The reason we say connecting to a source will reduce crosstalk is because sources have low output impedance so it will suck away all the unwanted noise. Load/receivers however are generally high input impedance. Like 100k or whatever, who knows how high that is with regards to calculation but let's just say it's high.

So with an isolation of only -30dB at certain frequencies, if you use it as a 1-to-4 switcher, the unselected outputs will still be playing sound at -30dB... That's a pretty bad switch.

Fair point.

The one I have (Skytronic audio source selector), doesn't seem to have any crosstalk that I ever noticed, but has one major flaw: the ground pin is shorted across all inputs, which can create some nasty ground loops if one of the inputs has a floating ground.

 

[nintendoeats]

Thanks Amir.

If only one of the four sources connected is playing at a time, no problem though. And that might be the main use case.

Unfortunately not for me.
I bought two 8-way switchers which appear to be of exactly the same design. My intent was to have one to control which device was playing, and one to control which device was recorded to.

Sadly, once I rigged the whole thing up I found that there was a ground loop (or some kind of noise) which went from inaudible to overwhelming as I moved from the lowest input to the highest on one of the boxes. It didn't matter what devices I was using, or which input they were on, that noise was always there as long as there was a device connected to the box.

Is this partially because I'm asking too much of a cheap passive setup? Probably, but the fact is that the internal design of the switch was clearly contributing.

 

[nintendoeats]

In case there still are dinosaurs using RCA composite video these days... IDK.

But for the price, the passive preamp is acceptable. Thanks, @amirm

*Looks over at his Betamax, VHS, PS1, N64, NES...*

 

[musicforcities]

In case there still are dinosaurs using RCA composite video these days... IDK.

But for the price, the passive preamp is acceptable. Thanks, @amirm

Could one use the composite video for digital coax (spid

In case there still are dinosaurs using RCA composite video these days... IDK.

But for the price, the passive preamp is acceptable. Thanks, @amirm

could one use the composite video for coax digital audio instead? Or for a subwoofer? Or would there be an impedance issue due to internal configuration?

Just curious.