A simple mic switcher project

Danny1969

So I made this little box to solve a problem. For the penultimate song of the last set our drummer comes out from behind the kit and sings lead vocals at the front of the stage. That means either taking his wired mic off the stand and threading the cable out front or having another mic already plugged in out front with it's channel on the desk set exactly the same in terms of level and EQ  / IEM mix. Or having a nice wireless mic instead of a wired one but these tend to be pricey and it's actually harder and harder to get clean wireless channels at venues now, it's so congested with traffic. 
Well we are maxed out channel count wise and not going to buy a £300 wireless mic for one number. 

This is a simple and very cheap solution that cost £20 in parts. It has 2 inputs for 2 mics, and one output to the desk. The first footswitch mutes the desk, the second one switches between the 2 mic inputs. The red LED on the left means both inputs  muted and the right LED changes colour from red to green to show which mic is now live. 

To mute a balanced signal simple short pin 2 to pin 3, that's what the mute button does. Selecting which mic is done with 3PDT footswitch. The output XRL pin 2 and 3  is wired to the centre of the switch and the 2 available inputs are wired either side, just like a guitar pedal that switches the output jack to either the input jack or the output of the effects circuit. All grounds can be wired and left together as they are common. 

There's a 9V battery in the box simply to run the LED's which have a 3.3K resistor in series  battery. This value is about right to see the LED's without them being distractingly bright on a dark theatre stage. 



Used it last night at the lovely Trading Boundries venue in Uckfield and it worked a treat 

Whistler

Normally we say that clever people think outside the box but you have managed it inside the box. Well done, Danny!