XLR: split cable or switcher?

[zambembe]

Hi,

I want to use the balanced XLR outputs of my M1-ViNL phono preamp.

Problem: my preamp has only one balanced input, which is already being used by the DAC. And I would like to use both the phono preamp and the DAC (not at the same time of course) without the need of plugging and unplugging the same cable each time.

A splitter ("Y" cable) would be enough to solve my problem?

My DAC has a on/off switch, but not my phono preamp: it is a "stand-by" model. That's what worries me. Obviously, my knowledge of electronics is near to zero.

[analogaudio]

you can use a "Y" cable to split a sound from one source to two destinations. You cannot use a Y cable to combine two signals into one, it doesn't work that way. A switcher is a better idea.

[zambembe]

Thank you for your answer, analogaudio. It makes a lot of sense.

Just to make myself clear, I do not intend to combine two signals into one; I just want to share the same input among two outputs - but never ever using both outputs at the same time:

DAC ON / Phono preamp OFF (stand by)
DAC OFF / Phono preamp ON

As a matter of fact I would prefer to use a passive switcher, but they seem to be a bit expensive (for what they offer). Of course, I don't want to "offend" the original signals with bad quality gear. It would be better to use a RCA cable with the phono stage instead.

[Jim Leach]

You have to bear in mind also that any XLR switch gear has the possibility to sound worse than an RCA cable of reasonable quality.

If you manually switch the input and just HAVE to have the phono balanced (I personally think the phono signal would benefit from a balanced signal more so than the digital source but your mileage may vary) run the CD as the RCA and the Phono as the balanced line.

[zambembe]

I'm afraid you're right, Jim Leach - thank you.

For instance, the maker of this switcher:
http://www.kramerelectronics.com/downloads/pdf/product/1/VS-4X.pdf

does not inform the THD. And the maker of this one:
http://www.arx.com.au/pdf/AUDIBOX_combiner_switcher_bro.pdf

does inform it (max. 0,2%) but it is a lot bigger than the THD of my DAC (max. 0,0015%) and my Phono stage (<0,01%). I'm just a newbie but - as far as I can see - this means that the switcher would introduce some distortion in the signal.

analogaudio is also right. It's very unlikely to use a Y cable without degrading the signal.

My DAC sounds good with a RCA cable, but it sounds even better with a balanced cable. So there's no hope for me? I do not like this word very much, but... there's nothing like an "audiophile" switcher in the market?

[jlbruyelle]

It is perfectly normal that Kramer don't quote a distortion figure for this switcher: it is a mere mechanical switch, so it effectively doesn't add distortion. As for the other one, the distortion is caused by a passive isolation transformer, not by the switch itself. It is therefore not quite transparent, but it would be a mistake to believe that this .2% THD will ruin the signal, actually it is not at all like semiconductor-generated distortion - quite a lot of (reputable) engineers swear by this property of transformers to "improve" the sound, and would not touch a transformerless mic pre with a 10-foot pole. Also, note that the transformer is there to prevent ground loops (ie. mains hum), and it thus avoids problems in quite a few situations, although hopefully not in your case.

Now for your problem: analogaudio is perfectly right, a Y cable is good to distribute one output to two inputs, but using one for output sharing is begging for trouble. If you want to share outputs, your best option is either a mechanical switcher (Kramer is a decent broadcast equipment manufacturer), or a patch bay which is just a professional way to rewire more conveniently, all passive, nothing more than 2 connectors and a few cm of cable.

Example of decent patch bay at a reasonable cost: http://www.neutrik.com/en/products/audio/patch-panels/1/4-patch-panel/nys-spp-l1

Example of simplified patch bay (actually a mere panel with XLR connectors that you have to solder yourself): http://www.xlrpatchpanels.com/

Ok, the patch bay is a bit more cumbersome to use, does not look as sexy as "audiophile" stuff, but it is hard to beat in terms of simplicity, quality and reliability. Look at what the studios use, think that all your records were recorded through it, and see if you can live with the looks of it - WAF can be a problem, that would be the most relevant objection I reckon

Also, it is not clear to me whether you want to mix balanced and unbalanced signals. If so, adapters are necessary to match the levels, and it is much easier to convert balanced to unbalanced than the other way round.

[zambembe]

a patch bay which is just a professional way to rewire more conveniently, all passive, nothing more than 2 connectors and a few cm of cable (...) it is hard to beat in terms of simplicity, quality and reliability.

That's precisely the idea: some Neutrik connectors, some wire, a switch; and (definitely) nothing fancy like a circuit board. Just balanced signals. An easy task, really.

As I have no experience with electronics, I've contacted a knowledgeable technician. Let's see how much he will ask for the service.

For "WAF" do you mean "Wife Approval Factor" or "Wife Appeal Factor"? Well... It seems that I would have to convince her that a tiny bit of ugliness will make everything looks more... "balanced"?

Merci bien, jlbruyelle. I'm getting serious help here at vinylengine and this is priceless.

[jlbruyelle]

For "WAF" do you mean "Wife Approval Factor" or "Wife Appeal Factor"?

I was slightly less ambitous, I just meant "Wife Acceptance Factor". Good luck on all the diplomatic work

[zambembe]

Thank you, jlbruyelle. I'll be back and let you know what happened.