KVR Audio

szurcio · Post by **szurcio** » Sat Feb 22, 2014 10:15 pm

I'm looking for something that could switch between 2 digital coaxial (not toslink) inputs. I use digital outputs from 2 synths and my audio interface has only 1 spdif input. In an ideal situation, I would just select which instrument I want to use without having to unplug one coaxial cable to plug in the other. Does such a thing even exist?

aciddose · Post by **aciddose** » Sat Feb 22, 2014 10:40 pm

That would just be a single ordinary mechanical switch. Are you using RCA or BNC jacks? Yes I have seen switches for just about every connector type you can imagine, and if you have trouble sourcing one type of connector you can just adapt to another.

Phil999 · Post by **Phil999** » Sat Feb 22, 2014 10:48 pm

one solution is to make a hardware switch yourself. I did this, and doubted that this would work, but it does. It's a 3-way switch taken from an old tape deck or amp, and I can switch between three sources. The connection is done instantly as long as the source is sending SPDIF. I have this since a couple of years, the switch is attached to a 19" rack, and I still find it kind of cool to manually change the SPDIF input with a simple mechanical switch.

Sure there are more sophisticated solutions, costing lots of money. One more reason why I'm so happy with my primitive hardware switch which costed me nothing. And working perfectly well. It takes about a second for the receiving unit (in my case a t.c.electronics M.One) to recognise the source/sampling rate.

szurcio · Post by **szurcio** » Sat Feb 22, 2014 11:23 pm

I use coaxial spdif cables. I found something like this for toslink cables:
http://www.amazon.com/ViewHD-TOSLINK-Di ... =pd_cp_e_0
But I can't locate coaxial switchers.

aciddose · Post by **aciddose** » Sun Feb 23, 2014 1:23 am

What you do mean coaxial? BNC?

Or do you mean like the screw connector for television cables?

Switch to BNC, you can find BNC cable switches no problem. There are tons and tons and tons from when coaxial BNC was used for ethernet.

BNC is the best connector for infrequently plugged cables. It is the connector for scientific or other purposes.

The screw connector (I'm not aware of the name of it) I'm not sure about. No idea why they choose to use this instead of BNC. Possibly at the time it was standardized, BNC hadn't been invented.

BertKoor · Post by **BertKoor** » Sun Feb 23, 2014 11:02 pm

spdif on coax is usually RCA plugs, not BNC. As said, ANY switch will work. Here's one not too expensive:

aciddose · Post by **aciddose** » Sun Feb 23, 2014 11:19 pm

Normally RCA/phono of course, but I just couldn't figure how you'd be unable to find a switch. Easy to find RCA switches and they can always be adapted to something else with very little effort.

RCA/phono is pretty much BNC with a thicker center pin and no twist-lock.

camsr · Post by **camsr** » Sun Feb 23, 2014 11:22 pm

Not all switches are the same though, don't try something that simple with high currents!
For SPDIF it's okay, but a quality switch ensures no blown electronics.

szurcio · Post by **szurcio** » Mon Feb 24, 2014 4:14 am

aciddose wrote:Normally RCA/phono of course, but I just couldn't figure how you'd be unable to find a switch. Easy to find RCA switches and they can always be adapted to something else with very little effort.

RCA/phono is pretty much BNC with a thicker center pin and no twist-lock.

I found some regular RCA switches but wouldn't they also convert digital to analog? I wanted to keep digital audio all the way through to the interface. I'm sorry for my ignorance...

aciddose · Post by **aciddose** » Mon Feb 24, 2014 4:46 am

That doesn't make sense. To go from digital to analog, there would need to be a DAC. It is a switch, not a DAC.

The digital signal is a series of pulses (on/off) on the line. It is exactly like an analog signal, only it is digitally clocked and only contains square-waves (pulse waves).

A digital signal is already analog, it never stops being analog. What makes it digital is that it has certain properties, as I said it is divided down from a clock and has only two states (0,1).

So a digital signal is a special type of analog signal that follows certain rules.

Switching either type of signal is exactly the same. You just connect the wires together.

A switch is exactly like unplugging the wire, then plugging into another position. The reason we use a switch instead is so we don't need to do this unplug/plug over and over again, a switch is easier to use.

BertKoor · Post by **BertKoor** » Mon Feb 24, 2014 9:32 am

aciddose wrote:I just couldn't figure how you'd be unable to find a switch.

Well, if you go looking specifically for a spdif switch, I'm not surprised you find none.

As stated above, a switch is just a switch. Unless the box requires a mains power adapter or batteries, then it contains electronics which could not let the digital signal go past it undistorted (it has very high frequency content, but otherwise it's just an electrical signal)

ZapAxe · Post by **ZapAxe** » Thu Aug 13, 2015 5:14 am

Being I use multiple computers with their own sound cards, all with s/pdif's on them, and also I wanted the ability to instantly route any one audio card to any other one, or one sound card to all others simultaneously...I bought an 8X8 Matrix Switcher that's actually designed switching s/pdif. It's a video & audio switcher, but I bought it just for it's s/pdif digital audio capability

ZapAxe · Post by **ZapAxe** » Thu Aug 20, 2015 6:11 am

Added....Tested out the Matrix Switcher with a few PC's running VST System Link, the 1st PC (set as the Master Clock) can send the VST System Link data and audio simultaneously to any number of PC's to follow as slaves. This means no having to go in and out of each PC with the digital audio cabling in a ring network, which successively adds a tiny bit of latency. With the Matrix Switcher, all slaves receive the VSL data at the same time.

aciddose · Post by **aciddose** » Thu Aug 20, 2015 7:07 am

PC please.

You mean "clock/data consumers".

ZapAxe · Post by **ZapAxe** » Thu Aug 20, 2015 2:32 pm

"PC please"? You're asking what my PC specs are? Or splitting hairs over calling a computer a PC? My specs are old/cheap to keep things affordable for the purpose of experimentation...They're all Win XP quad core's w/ 4 GB ram.

Yes, s/pdif is a 'consumer' rated protocol, PCM audio I believe, but that shouldn't cause anyone to run for the hills, if that's what you mean? 1/4" phono plugs are also 'consumer' type connections, that doesn't stop everyone from using them either. s/pdif in my opinion works fantastically

Anyway, this Matrix Switcher was bought used from eBay. Others had suggested a more expensive type unit designed for the music recording environment, but those mostly either had BNC and listed for a higher voltage than s/pdif has, and/or they were several hundred dollars. This used ShinyBow matrix Switcher was fairly inexpensive, and was designed for home & business, for using multiple composite video, and audio (analog & digital) equipment and environments. I only needed the specifically designed s/pdif connections of this unit, it's lower cost justifies having more capabilities than I'll use.

Having just completed all my testing this Matrix Switcher last night, it works just as I hoped it would, flawlessly for properly sending /distributing the s/pdif input signal, simultaneously to multiple s/pdif outputs. As mentioned before, these units have distribution amplification, so that each output is the 'exact' signal...carrying the digital audio, as well as te clock information that was send from the master clocking device.

Some of the above switches mentioned in this thread would not work for my own particular purposes, but for others yes. Matrix switching allows for much greater flexibility...maybe too much for some.

SPDIF coaxial switcher?