Keyboard's and DI Boxes

[partyadz]

Hi All

 

Do you always need to put a keyboard through a DI box, or can you just plug it straight into a mixer?

 

Many thanks for your help

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[iamchristuffin]

AFAIK, you can plug straight into the mixer, but it will be an unbalanced signal, so there will be more distortion, and a more 'dirty' signal.

[bruce]

AFAIK, you can plug straight into the mixer, but it will be an unbalanced signal,

Mostly OK so far...

so there will be more distortion,

That's nonsense. I suspect you may be thinking of what happens when you plug a line-level source into a mic-level input. That will distort, but it's nothing to do with the balanced/unbalanced issue

and a more 'dirty' signal.

What's a 'dirty' signal in this context?

 

Have a read through the archives and wiki on the balanced/unbalanced thing. The balanced signal will be less susceptible to interference (which is not the same as distortion) especially on long cable runs. However, in many environments, with short cable runs, the difference is insignificant.

 

So I guess the answer is that if you are plugging a typical keyboard into a mixer with balanced line-level inputs, it's good practice to DI, but not always necessary. But tread carefully, especially if phantom power is involved, otherwise you may end up sticking 48V into the outputs of your keyboard :)

[Just Some Bloke]

In other words,

Do you always need to put a keyboard through a DI box

No

or can you just plug it straight into a mixer?

Yes

 

Long cable runs would be better with a DI but short runs are usually OK going straight into the mixer.

 

Question answered!

 

P.S. I'm was pretty sure the same question had been answered before and was going to close this one so if anyone had any further points to make they could all go in the same place. Unfortunately I searched and couldn't find anything the same thing. If anyone can, could they please either PM me or use the 'Report' button so we can keep things neat and tidy? Many thanks.

 

Edit

 

Thanks to Mark for pointing out this thread which contains some useful information along similar lines.

[StevieR]

In addition to the balancing effect for longer cable runs, a DI box can also be useful in situations where the signal level needs padded down to correct gain problems. Normally though, a keyboard should happily plug directly into a mixer.

[TallMike]

just be careful if your desk has global phantom!

[paulears]

Global phantom on an unbalanced line input - phantom's not an issue on line level inputs, just balanced mic inputs

[timtheenchanteruk]

depends on the keyboard, I have come across a couple (Korg & Roland I Think) that have more than one output, and are balanced, I usually DI, to keep the feed to the players own amp, and provide a balanced signal.

[TallMike]

Global phantom on an unbalanced line input - phantom's not an issue on line level inputs, just balanced mic inputs

 

I should have made myself more clear....

 

You need to watch the phantom issue if you're using an MXLR to Jack adaptor then into your multi, which is invariably patched into the Mic inputs.

[paulears]

I really can't see there is much of a problem here - there are more synths and keyboards plugged into recording systems than ever played live - and very few of these get DI'd. Most people simply plug them into the line inputs, and they match really well. The only downside I ever have is that without a DI on stage - the cable length to the mixer is a bit long, and HF suffers, but plugging a keyboard into a mixer line in has rarely given me any grief. None of mine in the studio are DI'd, and they take up the vast majority of my mixer channels. Most keyboards use horrible wall-wart power supplies anyway, and have a plastic earth pin, making ground loops less likely anyway. Even on my keyboards with proper IECs they seem to be well designed and can be plugged into other kit without any problems. On stage, I normally DI simply to squirt them down a mic circuit - as I suspect most of us do.