# Problem with Mackie SR 24.4 VLZ Pro mixing board



## NoizeHexagonz (Dec 10, 2012)

Hi,

I recently purchased a used Mackie SR 24.4 VLZ Pro mixing board. When I began to use it, I zeroed the console as the manual told me to. However, I am having a serious problem with it. To test it, I hooked up a Microkorg to the mixer by way of quarter-inch cables, and both the cables and Microkorg were individually tested and work. I plugged the 1/4s into the jacks on channel 1 of the mixer, turned up the trim, unmuted the channel, and pushed L-R and got no signal at all. When I unplugged the left 1/4, I got a clear sound signal to the right output and a buzzy, distorted version of the right output on the left output. When I pushed the solo button, both left and right played the right output of the Microkorg clearly. I switched cables and plugged the left out of the Microkorg into the right input on channel one. Same thing happened as before, but with the left channel of the Microkorg's sound this time. When I plugged the right out of the Microkorg into the left in of channel 1 on the board while I had the left playing fine in mono on solo, all output from the board disappeared. When one of the 1/4ths was plugged into the left input of the board, I got nothing at all. This same thing happened on every channel I tried, 1-8, and the paired ins on 21+22 and 23+24.

Does anyone know what this problem is, and if it is possible to fix? Thanks


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## NZM (Dec 10, 2012)

Channel 1 on that console is a mono mic/line input so you cannot connect both Left and Right outputs of the Microkorg to Channel 1 at the same time. The connectors on the back of the SR24.4 will be an XLR for mic input, just above that is a 1/4" socket for a balanced "Line" input. Then above the Line input is another 1/4 socket labeled "Insert". If you are connecting your Microkorg to the two 1/4 sockets on channel 1, then you have one as Line Input (correct place for one channel) and have the other connected as a channel insert (wrong place).

For a steroe input device like the Microkorg you need to connect Left to channel 1 Line input nad Right to channel 2 Line input. And if you want to operate stereo then pan channel 1 to the left and channel 2 to the right.

Note that channels 21 & 21, and 23 & 24 are designed as Line input only (no mic pre-amp) and you could connect the Microkorg to 21/22 or 23/24 inputs.

The "Insert" socket is used to "insert" an effect unit (perhaps a graphic EQ, compressor, gate etc) into the channel. So it uses a "stereo" jack (known as TRS) to send the signal to the effects process and to return the effects processor output back into the channel. The insert function normally takes the signal from before the channel EQ and returns it to the same point in the signal path. See insert cable in the wiki.

So try using channels 1 and 2 and not just using channel 1 for your stereo input from the Microkorg.


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