Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[PaulyD]

Forgive me for asking such an embarrassingly simple question. I've been Googling, forum searching and even went to the cabling section of the Study Hall here. Unfortunately, the link is broken to the ProCo sponsored article that likely would have answered my question. Anyway, when connecting the XLR outputs of a DAC to the XLR inputs of a power amp, is there a specific type of XLR cable that should be used? I've seen XLR cables advertised as specific to AES/EBU, mic and speaker connections. Are these all generally the same with the difference being the quality of conductors and shielding?

Also, are speaker switchers considered a no-no?

I'm preparing to install a new power amp and don't want to hamstring its performance out of ignorance.

TIA,

Paul

[Wire]

For your application you are using a DAC analog out into the analog in of the amp.  A standard high quality "mic" cable will be fine. AES is not required, though some people prefer them for analog use as well due to their copper quality.

The connectors are generally the same, you may see some with Gold contacts some with Nickle but the build and function is the same.

Speaker switches... Well it depends on the app.  Figure every recording console has a speaker switch in it!

Any other questions feel free to shoot me a email

[Bob Olhsson]

wire wrote on Tue, 15 March 2005 23:59

... AES is not required, though some people prefer them for analog use as well due to their copper quality...

Copper quality? What about low capacitance?

[Wire]

BOB: Copper quality? What about low capacitance?....

Yes AES wire on average is about 1/2 the capacitance of a high quality mic wire. It was too late last night when I posted it to go beyond copper quality!! haha

[PaulyD]

The first reply I got to this thread was by PM. That person said there is also a difference in nominal impedance between mic and AES cables. They also said to use mic cables.

Thanks to all for the help.

Paul

[PaulyD]

wire wrote on Tue, 15 March 2005 21:59

Speaker switches... Well it depends on the app.  Figure every recording console has a speaker switch in it!

Well, what I had in mind was one of those boxes that goes between the outputs of a power amp and several sets of passive speakers.

I have been looking over units from Atlas Sound, Monster Cable, Rotel, etc. I do not want one with pots on it. Unfortunately, I haven't found any rack mountable units that fit my needs. After much Googling and reading, I'm eyeballing the Niles Audio HPS-4. I'm kind of surprised no one has chimed in with any thoughts or anecdotes on whether these things degrade amp performance. It wouldn't be that big of a deal to use a patch bay instead, but I'd prefer the Niles Audio box.

Paul

[Wire]

Paul, ooops.  I guess I didn't phrase that correct, what I meant was speaker switchers are used in every large format console so adding them into your system shouldn't be a problem.

I have used the ADCOM box which was very good, but it was just switching nearfield monitors, not mains or anything like that so the power going through it wasn't huge.

[PaulyD]

wire wrote on Fri, 18 March 2005 20:52

"Paul, ooops. I guess I didn't phrase that correct..."

Naw, you're cool. I'm just not pro enough yet. hehe

Quote:

"...what I meant was speaker switchers are used in every large format console so adding them into your system shouldn't be a problem I have used the ADCOM box which was very good, but it was just switching nearfield monitors, not mains or anything like that so the power going through it wasn't huge."

Excellent. That's exactly what I what I needed to know. Likewise, I'm just planning to switch between near field monitors. The amp I'm going to use is 350W/ch, which is more than the 250W/ch the Niles Audio box is rated for, but I don't monitor at real high volume levels, so it should be fine. If anything, I'd rather blow out the Niles Audio box than my speakers.  

Thanks again!

Paul

[bobkatz]

Check with Alan Silverman, who posts on this board. He just bought a very high end speaker switcher that is not cheap. Do not skimp on speaker level switch boxes. You really need one that can handle the switching current and not degrade over time.

BK

[cgc]

http://bryston.ca/2switch.html

What about this Bryston box?  The price seems reasonable and their amps aren't exactly shoddy.

[amwintx]

I use that 2 channel bryston box. It has very high quality switches and binding posts. I highly recommend it as far as sound quality/transparency goes. My only complaint would be that it is a little difficult to get bare wire into all of the binding posts on the back as they are very close together.

[Arf! Mastering]

I got the ProCo RMS-1A.  It has heavy duty switches and wide-gauge internal wiring.   The Bryston box looks good and is $100 cheaper.     The proco is three-way.  Bryston offers 3-way that is the same price as the Proco.  The Bryston seems to allow split to multiple speaker systems but the Proco is one system at a time only.   You might check whether any load resistors are in the Bryston - the Proco is switch and wire only - no loading or padding.

[PaulyD]

Alan,
thanks for chiming in. Electronically, That ProCo box is precisely what I was looking for since I likewise only monitor from one set of speakers at a time (if only it were rack mountable... ). Any of the units that allow use of more than one set of speakers running at the same time are either using what's called an "autoformer" or resistors to maintain impedance load. Before you pointed out the ProCo box, I was looking at the Niles Audio box because the "protection circuit" (resistors) could be manually switched out. But one has to be careful with the Niles Audio box because if a third pair of speakers is activated without the protection circuit enabled, impedance would drop below 4 ohms, for which most amps are not rated, of course. Between autoformers and resistors, I figured resistors were the lesser of two evils. If you look at this unit, you can see what they are calling an autoformer looks to be what was likely designed for power supplies. Obviously, these units use inductive reactance to maintain impedance. I just don't see how these things could not color the sound, not to mention fluctuating impedance. Simple wires and switches == good! Considering what simple devices these things are, I'm really tempted to build my own into a 1U rack mount box without any headphone circuits (got the headphone thingy well covered already ).

Thanks again,

Paul

[Wire]

Paul,

If you get one that isn't rack mountable, I can make you some custom sheet metal, that would get it into a rack perfectly, but it may not be 1 RU, all depends on the size of the unit.

Let me know if you ar einterested thanks.

DH

[Geoff Doane]

PaulyD wrote on Thu, 17 March 2005 00:43

The first reply I got to this thread was by PM. That person said there is also a difference in nominal impedance between mic and AES cables. They also said to use mic cables.

I realize the thread is a bit stale, but just in case anybody still cares:

AES/EBU cable is 110 ohms, because that's what the AES spec calls for, and it can make a difference with moderate lengths.

Mic cable is typically 30-50 ohms, but it doesn't matter what the characteristic impedance is for analog audio unless you're the phone company (cable lengths approaching 1000 ft. or so).

For simplicity at my facility, we use 110 ohm cable for just about everything these days so people can't grab the "wrong" cable in a hurry, and the "digital" cable is actually easier to install than some of the "analog" stuff.  The exception is mic cables that are used between the mic and wallbox, where durability is the primary concern.  I still like XLRs with silver plated pins.  Solder sticks to them more easily, and even when silver oxidizes, it's still conductive.  I don't turn up my nose at gold plated connectors, I just wouldn't normally spend my own money on them.

For speaker switchers, I would stay away from anything that actually switches the output of the amp.  A better plan would be to switch the DAC output at line level between the inputs of two amps.  You could then trim the gains of one of the amps so that the monitors have the same volume.  If using a second amp isn't an option, a speaker level patch panel using Neutrik NL4 Speakons would be my next choice.  The Speakons were designed from the ground up for speaker use, and with four poles in one connector, you can switch left and right at the same time.

Geoff Doane

[Wire]

Quote:

The exception is mic cables that are used between the mic and wallbox, where durability is the primary concern. I still like XLRs with silver plated pins. Solder sticks to them more easily, and even when silver oxidizes, it's still conductive. I don't turn up my nose at gold plated connectors, I just wouldn't normally spend my own money on them.

Geoff: I have a couple questions about this.

If you need AES mic cables out of durable that's not hard to find.  There is wire I use by Mogami, Gotham, Gepco and Canare that is AES that is just as durable if not more than any analog mic wire.  What are you using that you don't think is durable enough?

Also I have a custom cable shop/install company, and have soldered 1000's of Neutrik Silver and Gold connectors, and the solder definately flows much better on the Gold contacts, as well the contacts last soooo much longer with the golds and only end up costing about $1.50 more per cable to use.

[Geoff Doane]

wire wrote on Mon, 21 March 2005 22:59

Quote: The exception is mic cables that are used between the mic and wallbox, where durability is the primary concern. I still like XLRs with silver plated pins. Solder sticks to them more easily, and even when silver oxidizes, it's still conductive. I don't turn up my nose at gold plated connectors, I just wouldn't normally spend my own money on them. Geoff: I have a couple questions about this. If you need AES mic cables out of durable that's not hard to find.  There is wire I use by Mogami, Gotham, Gepco and Canare that is AES that is just as durable if not more than any analog mic wire.  What are you using that you don't think is durable enough? Also I have a custom cable shop/install company, and have soldered 1000's of Neutrik Silver and Gold connectors, and the solder definately flows much better on the Gold contacts, as well the contacts last soooo much longer with the golds and only end up costing about $1.50 more per cable to use.

My info on flexible AES cable may have been a bit stale.  I see Canare has a DA206 cable that looks like it should work.  Maybe I should try some the next time I need a batch of mic cables.  The nature of the 110 ohm impedance means that for a given gauge of cable, there needs to be more dielectric, making for a cable that's bulkier than an analog one might be.  I normally favour the L-2T2S.  It has significantly less capacitance than the Star-Quad (that's something the manufacturers never make a big deal about   ), and I've yet to have a problem with noise pickup in real world situations.

We use Delco and AVP wire for AES/EBU (and any analog installed wiring too).  It's easy to work with and cost effective, but has a foil shield.  Luckily, in our facilities at least, the digital wiring tends to be installed, while it's only the analog wiring that gets rough treatment on a stage or studio floor.  One exception is some newer AVP TRS patch cables which have a braided shield, small diameter, and claim to be 110 ohm.

For the XLRs, I have seen some older gold plated ones that have lost most of the gold off the pins from wear.  Maybe I just don't notice it as easily on the silver pins.  I can't explain the difference in soldering, except it just seems easier with the silver inserts.  I also use Neutrik plugs, and usually Kester 44 63/37 solder.

Geoff

[amwintx]

One more point regarding the Bryston speaker switch box. I realize that it may seem like pointless functionality to be able to switch more than one pair of studio monitors on at the same time, but the Bryston box allows me to switch my subwoofer on and off while leaving my mains on - which really helps me get a feel for what it is contributing to the sound.

[Wire]

Geoff : Thanks for answering... Yes the Canare you mentioned is very flexable.  I also use Mogami 3080 (Normal 22 or 24 guage  I can't remember) and Mogami 3173(18 guage pretty heavy duty) and both are very flexable.  

Those are my fav's but there is def AES wire by the others that is flexable as well. You should shoot me a email if you need to pick up some cables out of the Canare or Mogami I always have them, any length.

As for the connectors yes the Gold can wear off over time, but a nickle contact XLR (Silver) will oxidize like you said and over time will end up black.  For me the golds last much longer and the gold helps the solder to flow.

I use Kester 44 60/40 but both are great, and you should get a better flow on the golds. Thats interetsting

Yeah they make Patch cables 110 ohm sometimes in case you put AES in the bay.

Shoot me a email if you need any cabling dave@livewiresi.com