Connecting Keyboards

So, you want to plug your keyboard into the church sound system, but don't know how?

Blake Engel, All Church Sound

So, your church is moving to a more contemporary service? Or maybe you've used a keyboard quite a bit in the past, but just don't know how to get it plugged into your sound system. Whatever the reason, the connection from keyboard to sound system is quite easy to make.

First of all, you need to find out where the audio signal comes out of your specific keyboard. Usually there's a jack on the back of the unit that's labeled "output" or "main output". There may be a single jack that says "stereo output", there may be a single jack that says "mono output", or there may be two jacks that are labeled "right output" and "left (mono) output". Most keyboards have either just a mono output jack or two mono output jacks (that, when used together, can provide a stereo output). We will consider these possibilities. The jacks will most likely be 1/4" TS (mono) phone jacks, so you'll need a cable that has a 1/4" TS (mono) connector on the end of it. Note that the output is probably unbalanced (read "Unbalanced or Balanced ...HUH?"), so a standard "instrument" cable is all that's required. Such cables have a 1/4" plug on both ends, and should be at most 10 feet long. If your keyboard has one mono output, plug the cable in there. If it has the two outputs, plug the cable into the "left" output jack (this will provide a mono output).

Great, now what happens with the other end of the cable? Unless your keyboard is sitting right next to your mixer, you'll have to convert the unbalanced signal to a balanced signal so you can plug it into a microphone jack on the platform (or end of the snake). To make this conversion, a direct box is required. A direct box is a device that not only physically changes the audio connectors, but it also changes the audio signal from unbalanced to balanced. This allows the signal to be run a long distance to the mixer without any noise or signal loss. Now all you need to do is use a standard microphone cable to plug the direct box into a microphone jack on the platform (just like you'd plug in a microphone!).

At the mixer, be sure to start with the gain (or trim) control all of the way down at first. Keyboards put out signals much higher than microphones. Check to see if changing the volume on the keyboard affects the volume in the sound system. If it does, you'll have to let the keyboardist know they shouldn't adjust it. You'll probably need to give them a monitor, too. If there's any humming or buzzing, it may be due to a ground loop. If your direct box has a ground lift switch on it, see if that helps. If not, there may be another problem. Give us a call, we'll be happy to help!