DI lead

[deranged-angel]

Hi All,

I've been asked to get hold of a DI lead to use with a guitar but I'm not sure what it looks like. I've tried searching google but the results are a little bizarre and I'm not sure what to narrow my search down to.

 

I've used a DI box before but I'd just like to check that I am setting it up right. Is this what I would do?....

 

1. plug DI box into Sound board using stereo leads

2. Whack the channel up to full

3. Plug Guitar into DI box using DI lead

4. adjust sound of guitar from DI box rather than from channel on sound desk.

 

Also, where could I hire just a DI lead from? We have various leads at the place I work but I'm not sure which it is. We have standard jack leads if these would work?

 

Also, does the DI box feed itself from the board or will it have a seperate power supply?

 

Thanks for your help

 

Em

xxx

[Ben Lawrance]

I think you may be a little confused.

 

I DI box turns an unbalanced line level signal into a balanced mic level signal. It can do it in 1 of 2 ways.

 

Active DI boxes use a PP3 battery or the desk's phantom power to give it juice to be able to work.

 

Passive DI boxes do not use power at all. They just plug and play.

 

 

In your situation. What you need to do is plug the guitar into the DI box with a Jack - Jack lead (standard guitar lead) into the input, and then use a balanced XLR cable to connect the output to the mic input on the desk.

 

The DI box won't have a volume control on it, just and attenuation switch, which lets you choose how much to attenuate the signal (unless it's an expensive one, and has differant inputs with differant attenuations)

 

What you the need to do is get the level right on the desk using your input gain, (so you do not go into the red) and then use the fader (or knob) as a volume control.

 

 

Any more help, just ask

 

 

Rgds

Ben

[Big Dave]

Last thing I saw that was refered to as a DI lead (which was a long time ago) was a standard 1/4" Jack to XLRM and it did exactly what it said on the tin.

 

I'm sure (or hope) they are refering to a using a DI Box. See above for the useful bit.

[deranged-angel]

Oh right, easier than I thought then!!

 

Thanks Ben!! Can I just ask, though, what would happen if I put the jack straight into the board? Why would the sound be 'unbalanced' and what exactly would it sound like?

 

Thanks

Em

x

[charlyfarly]

I would just like to add a couple of remarks to Ben's post.

If your guitarist is using an amp he will need to get signal to this as well. If you look on the DI box you will notice that it has two jack sockets. 'Input' for the guitar or guitar radio receiver output and the one next to it is a parallel 'Output' which you connect (using another guitar lead, a short length of jack to jack will do!) to the input of his amplifier.

Note that some passive DI's do not have attenuators on them. You will need to set the input level on the desk as mentioned before.

[brad!]

Just mic the damn guitars up ** laughs out loud **!

[JohnPartridge]

Ye, I prefer miking up to DI.

 

The DI cable is normal XLR cable

[paulears]

Oh right, easier than I thought then!!

 

Thanks Ben!!  Can I just ask, though, what would happen if I put the jack straight into the board?  Why would the sound be 'unbalanced' and what exactly would it sound like?

 

Thanks

Em

x

<{POST_SNAPBACK}>

 

The sound isn't audibly unbalanced, it is an electrical interconnect issue.

 

Have a quick look at the zillions of posts when you type 'unbalanced' into the search box. This should tell you all you need to know. You can plug the guitar into the desk, but the line input of most desks expects around three quarters of a volt, as in what comes out of the line output of keyboards, cd's, md's etc - guitars are less than this, so you have to wind up the gain a bit, which also brings up the hiss and noise in the background. You'll also need a very long lead if the mixer isn't close, and long guitar leads are bad news.

[david.elsbury]

Ye, I prefer miking up to DI.

 

The DI cable is normal XLR cable

<{POST_SNAPBACK}>

Not quite, the cable from guitar to DI is a standard 1/4" (6.35mm) jack to jack guitar lead, as used for plugging said guitar into amp. This is what I belive the OP is reffering to when saying "DI lead."

 

The output cable is a standard XLR-XLR mic cable from the XLR out of the DI to an XLR mic input on the mixer.

 

David

[Jivemaster]

There is method in DIing! Guitars are very high impedance sources and need a high impedance termination ( we're talking 500k or so) close to the pickups (we're talking say 5 to 10 feet) or there will be excessive treble attenuation by the effective parallel capacitance of the jack - jack guitar cable.

 

You use a short lead from guitar to DI box properly terminating the Hi-Z source then send the transformed Lo-Z signal as far as needed down an electrically balanced line at a level to suit the desk. Passive DI -you are stuck with the signal level provided. Active DI gets power from either the desk's phantom or a battery better for long runs or splits but remember to change the battery can give gain.

[deranged-angel]

Thanks Jivemaster, and everyone else, for all your info.

 

I think I understand it- if the lead from the guitar to the DI is too long, the sound isn't as good-makes sense.

 

What does the Hi-Z and Lo-Z refer to exactly? I presume the Hi Z is the Guitar and the Lo is the board but what does it actually stand for?

 

Please check out my other posts with more confused ramblings!!!

 

Cheers guys

Em

xxx

[david.elsbury]

The "Z" is a short way of writing impedance, so High-Impedance and Low-Impedance. I'm not fully sure what exactly impedance is, sorry, so I won't confuse the matter by posting my thoughts on that.

 

David

[PoppaDom]

Just to add to what has already been said but I have been asked for a DI lead before whereby the band has specifically requested a cable designed with specific capacitance and resistance for utilisation with magnetic pickups.

 

Cable such as Guitar Cable, depending on the exact application and guitar involved even short runs of "normal" unbalanced cable can dramatically colour the sound...

 

Hope this adds constructively

 

Poppadom

[gnomatron]

odd that noone's passed comment on his actual use of di boxes;

 

 

I've used a DI box before but I'd just like to check that I am setting it up right.  Is this what I would do?....

 

1. plug DI box into Sound board using stereo leads

2. Whack the channel up to full

3. Plug Guitar into DI box using DI lead

4. adjust sound of guitar from DI box rather than from channel on sound desk.

 

1. is ok - except that in the case of a guitar it's usually going to be mono, unless the guitarist is using some odd effects, and you're taking your output from them, rather than the guitar itself.

 

2. - I'd not do this. If the DI box had a gain on it, I would set that to about 1/3, then get the guitarist to play a little while I checked the level of that at the desk using pfl, and also make sure I was getting any signal at all.

 

If you have to put loads of gain on at the desk end to get a good signal, then you can turn the DI up, if on the other hand the signal reaching the desk is too hot, turn it down.

 

Anyway, only once I'd (very roughly) checked the signal level would I turn the fader up on the desk, and then only to 0, not full. From that point I'd adjust the gain further to get a good level for the mix, then I'd do channel eq, monitors, fx.

 

3. - Argh! No! Never, ever plug anything into/out of a channel that's turned up! That nasty pop you hear is your speakers doing things they shouldn't be. It'll inevitably happen by accident quite often, usually because of guitarists, but avoid it if you can.

 

4. - See above, but basically you want to get the DI box to a level you can leave it at all night, and then have control from the desk. You need to balance it between getting a good strong signal for quieter moments of the guitarist's playing, and not being uncontrollably loud when he's Rawking Out .

 

Anyway, the other thing I'd keep in mind is that a lot of DI boxes don't have any gain control on them.

 

Oh, and as for your DI lead problem, I suspect he just means a lead to plug the guitar into a di, which will more often than not be a simple mono jack-jack, i.e. guitar lead; you'll need another one to go out of the guitar into the guitarist's amp, too. You'll also need to connect the DI to the desk, and that'll probably need an XLR-XLR, i.e. a mic lead.

 

And finally! I'd advise micing the guitar amp if you can, it'll sound better.

[PoppaDom]

odd that noone's passed comment on his actual use of di boxes;

 

<{POST_SNAPBACK}>

 

Her, her use of actual di boxes.....

 

Em?

 

;)