Jack (Bal and Unbal) Multicore

[spyder]

Hey everyone,

 

I've been looking around on the internet for a Jack Multicore and havent been able to find one anywhere, only those with XLR. I am looking for one which is about 30m long and has got 4 balanced and 4 unbalanced inputs and 2 balanced outputs from some sort of stagebox. Does anyone know if anything like this available?

 

Otherwise is it possible to use a normal XLR multicore with Jack XLR adaptors at the stagebox for mic, bass (needs power from mixer), and lead guitar?

 

Thanks

Amit

[Dj Dunc]

you cant put an unbalanced line down a cable more than 8m I find, as there is huge interference induced. Yes the normal way to put a guitar down a multicore is to use a DI box, which converts the unbalanced source into a balanced XLR. also a mic (to be any real good) should be an XLR anyway, and even then are very cheap for budget ones (£20 quid for a pack of 3 from behringer).

 

Also can you explain about the bass? I dont see what equipment youre meaning here.

 

hth

 

dunc

[StevieR]

It is not common to get a 30m multicore with jack connections, hence your difficulties in finding one. You could easily get a custom one done though.

 

As you suggest, however, it is perfectly feasible to use jack - XLR adaptors on a standard snake to perform the same job - just looks a bit messy!

 

Only thing to remember is that due to the distance, all signals should be balanced to reduce interference and this may require some DI boxes as Dunc suggests. What are the proposed inputs anyway?

[spyder]

you cant put an unbalanced line down a cable more than 8m I find, as there is huge interference induced. Yes the normal way to put a guitar down a multicore is to use a DI box, which converts the unbalanced source into a balanced XLR. also a mic (to be any real good) should be an XLR anyway, and even then are very cheap for budget ones (£20 quid for a pack of 3 from behringer).

 

Also can you explain about the bass? I dont see what equipment youre meaning here.

 

hth

 

dunc

 

thanks dunc.... I've just realised that I COMPLETELY forgot about using DI boxes thanks.... yeah I meant was that the bass would also need to be DIed in this situation

 

thanks for the quick reply

 

amit

[dbuckley]

If you are suggesting plugging a standard guitar into an XLR and thence down a multicore, the management regrets this wont work very well. Guitars need a high impedence amplifier, and a multicore is designed for low impedence sources, so although it will work a bit, you'll lose a lot of the guitar's tone on the way down the wire.

 

If you want to get guitar down a multi you need to get it into (preferably) an active DI, though a passive DI will be better than nothing at all. Even better would be a proper guitar preamp, or a modelling pedal with an XLR out.

 

A long (long, long, long) time ago, My First Multicore was a couple of 20 yard lengths of four core individually screened cable of the sort inttended to go 2m with a DIN plug at each end. It worked, but then again, the PA was a such mediocre quality that the shortcomings of the multicore were not a key issue

[bruce]

(takes a deep breath and counts to 10....)

 

While the spirit of much of what DJ Dunc says is correct(ish), he's using the terms "XLR" and "balanced" interchangeably. Which is wrong. XLR is simply a type of connector. "Balanced" relates to the nature of the transmission network. It's perfectly possible to carry balanced signals over jack connectors, and unbalanced over XLRs, although not particularly common. Not appreciating this difference can cause all sorts of problems - eg see the recent postings re confusion between "stereo" and balanced connections on TRS connectors.

 

 

Back to the original question - the reason you can't find a jack multicore is because there's no market for them.

 

You could, of course, use an off-the-shelf XLR-based one, and use XLR<>TRSjack adaptors for your balanced sends and returns. That would work fine - it's still a balanced connection, just a different presentation. While I don't think anyone would recommend using unbalanced signals over this sort of distance, you may get lucky and it may work. But using DI boxes or balancing transformers at the source would probably be the best way to proceed.

 

I say "probably" because I don't know what the source or destination equipment is. But that's just covering my back.

 

In the past I have used 50m unbalanced audio connections with success. But that was luck - I've also had problems with unbalanced links of less than 1m. It's not just distance that matters, it's the ambient electrical environment, the nature of the signal, and a whole host of other things.

 

 

Bruce.

[spyder]

Well basically this is the situation. We have a powered mixer and we want to set up so that the mixer is off the stage and at the back of the hall. This means that we need a way of connecting all of the instruments and mics on stage to the mixer at the back. This is bass guitar, lead electric guitar, acoustic guitar with pickup and a single mic (has jack connector).

 

In the past we've had the following setup for gigs:

The bass guitar connected directly to the mixer with a jack to jack lead

The acoustic guitar with pickup connected directly to the mixer with a jack to jack lead

The lead guitar plugged into its amp and the amp plugged into the mixer with a jack to jack lead

The mic plugged into the mixer with a jack lead.

 

Now, if I were to buy an ordinary multicore stagebox what other equipment would to be bought in order for the setup to work. Also, I would need a multicore with outputs too as master output from the mixer to the loudspeakers are with Left and Right jack leads while for the powered monitor, it would be a balanced jack lead.

[Chris Beesley]

Back to the original question - the reason you can't find a jack multicore is because there's no market for them.

 

We have them - but they tend to be either 4 or 8 way and available in balanced (trs) or unbalanced (ts) and only feature one type of connection ... not a mix.

 

HTH

 

p.s. some of the DAP Audio dealers (will also stock them - this is not a sales post ... just a factual one)

[bruce]

Now the situation becomes clearer....

...We have a powered mixer

 

That's the first problem. You will need reasonably heavy cables for your speakers - far bigger than any standard multicore. So you'll need to invest in separate cabling for this, or a power amp on-stage. The norm would be to just run mic and line level signals from stage to the mix position.

The bass guitar connected directly to the mixer with a jack to jack lead

The acoustic guitar with pickup connected directly to the mixer with a jack to jack lead

The lead guitar plugged into its amp and the amp plugged into the mixer with a jack to jack lead

The mic plugged into the mixer with a jack lead.

These are all unbalanced. The 3 guitars can be balanced via DIs, and then connected to the mixer via the multi. If the mic is unbalanced, I'd suggest getting a new one would be the cheapest option. However, it may actually be balanced, but being used with an unbalancing cable.

[spyder]

You say that those are all unbalanced but the DI boxes I see need you to plug two jack leads in to get a single XLR output. All of these inputs only currently use one jack to jack lead to get to the mixer. How would I plug these into a DI box?

[dunk_1984]

as above just DI everything that used to be Jack - Jack, and as for your mic if it isnt XLR I would suggest replacing it with one that is ... make and model budget dependant. - multicores I know they probably may not be the best but try a certain auction site... they have quite a few auction companies on there who will give you a good deal on a nice XLR multicore, and maplin will sell you XLR-jack adapters for a couple of quid if you need them... and again XLR cables well most places sell them....

 

and I recently had someone planning on running our powered desk back through the multicore.... It actually took a letter on Letterheaded paper from a third party to stop their one tracked mind...

 

You say that those are all unbalanced but the DI boxes I see need you to plug two jack leads in to get a single XLR output. All of these inputs only currently use one jack to jack lead to get to the mixer. How would I plug these into a DI box?

the DI's have 1 jack in a loop/return and a XLR out.. this is so that if DIing something like a guitar amp you can take a feed then supply a backline to the amp so they get an amp feed and you get a clean signal feed direct off the guitar.... so the DI would go between the AMP like an FX pedal would

[Bobbsy]

You say that those are all unbalanced but the DI boxes I see need you to plug two jack leads in to get a single XLR output. All of these inputs only currently use one jack to jack lead to get to the mixer. How would I plug these into a DI box?

On any standard DI box you just plug in a single jack lead and it gives you a balanced XLR output. I'm not sure what's given you the idea you need two leads, unless you saw a picture with two jack sockets. If so, the second socket is likely an OUTPUT, allowing you to loop through the DI to an on-stage amp as well as feeding the XLR line to the mixer. If this is what you saw, use of the second socket/output is optional.

 

Depending on your stage layout, BTW, you might look at some of the multichannel DIs such as THIS ONE which would do everything you need with room for expansion...and lists for £69.

 

Finally, just to endorse the warning against using a multicore for a feed from an amp to your speakers...mic and line level stuff shouldn't be mixed with the power levels output from amps, and the physical cables are far too small. The exception would be if you have powered speaker (or monitors) when the line output to feed these can easily travel on multicore.

 

Bob

[spyder]

Ahh, I understand now... Thanks everyone for the help and quick replies with this.

 

Thanks,

Amit

[Chris Beesley]

Soundcraft have a wealth of information on their site ... from mixing guides thru to connection information.

 

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