Our church has an Aviom monitoring system for the musicians and singers.
I helped lead the way in getting them installed and they are simply amazing. Imagine sixteen individual channels of audio at your fingertips giving you the ability to hear exactly what you want of each instrument in stereo.
They are a performers dream come true.
Our configuration is that the vocalists have floor wedges connected to the Avioms. This has worked out well in that each singer can mix in their own monitor settings without the need to communicate back to the sound board. There are some limitations with this setup however, primarily that the sound techs have no control over the overall stage volume.
There are times when everyone is turning up their monitor to hear and before long you have a serious volume issue on stage.
Because of this, I decided to move my team over to headphones to tighten up our playing and eliminate the problems of a loud stage. Since six of our Avioms are connected to amplifiers, this presented a problem of how to remove the feed from the amps and plug in headphones without creating a “buzz” as the ground was interrupted.
I couldn’t find what I needed searching on Google so I decided to make my own.
I wanted something small enough to fit on the Aviom mixer that would give me an out to the monitor and an out to headphones that could be switched without breaking the ground to the amp.
Here is the material I used:
2 – Metal Step Flashing $ .58
1 – 1/4 ” Grommet $ .30
2 – 1/4″ Stereo Jacks $ 4.00
1 – 1/8″ Stereo Jack $ 4.00
1 – 2 Pole Toggle Switch on/off/on $ 2.95
1 – 1/4″ Stereo Plug $ 1.50
24″ Microphone Wire $ 2.00
Metal Screws $ .98
I came up with an idea for a 1 x 4 x 1 inch box and proceeded to create a prototype out of cardboard.
You can see the cardboard model in this shot as well as the marked up flashing. I ended up using a different switch in the final design so the square hole was not required.
Layout on flashing.
The flashing was just the right size for this project and easy to work with.
Alex modeling safety glasses.
He put these on as a joke, but a piece of metal ended up bouncing off them! Protect your eyes when you work with this stuff!
Drill out all the holes for the jacks, switch and microphone cable. The final version has 2 holes on the switch side, one for the switch and one for the 1/8″ jack. The first switch I purchased was a 2 pole on/off which would not work, so when I found the small toggle I added the smaller jack as well to eliminate the need to use a headphone adapter since most headphones use 1/8″ plugs.
Drilling out the hole for one of the 1/4″ jacks. Be sure to clamp the piece down, you don’t want it flipping around slicing your fingers! Sadly, from first hand experience, thankfully I was quick!
Once the holes have been drilled, cut out the tabs with a tin snips.
Completed piece ready for bending before the modification for the new switch and jack. You will have to use your imagination, but there are two smaller holes on either side of the square hole on the finished piece. Obviously the square hole would not be needed.
Bend the tabs up ninety degrees with a hand seamer. You can see in this shot the marks for the new holes.
Completed bottom section with the ends down for soldering.
Install the grommet and feed the microphone cable through about 4 inches past the grommet into the box. You can use any length cable, but I only needed about 16 inches for the Aviom.
To secure the cable in the box, I slit the insulation down the length of the cable jacket to the grommet and stripped back the insulation to expose the wires. After unwinding the shield from the insulation, I removed the insulation to the grommet and twisted the shield into a wire. I then slit the stripped outer jacket down the backside giving me 2 pieces or halves to tie a knot against the grommet to keep the cable from pulling out.
Using another 5 inches of microphone cable, I removed the wires and shield and used them to make up the jacks and switch. Again, I twisted the shield into a wire which was soldered to the sleeve terminals on each jack, cable and case. It is important to tie all the shields or grounds together to keep the amplifiers quiet.
The rest of the wiring is simply attaching all the tips to the tips and all the rings to the rings through the double pole switch. When the soldering was done, all the sides were pushed up into place creating a compact box.
I don’t have pictures for this because I forgot to take them, and once I had it assembled the last thing I wanted to do was pull it apart!
The cover was simply a 3″ x 4″ piece of flashing bent at 1″ increments with some holes hacked in to pass by the switch, jack and grommet.
Here is the completed switch which worked perfectly without so much as a click when switching between headphone outputs and the powered monitor. It was as quiet as a church mouse. I attached this to the back of the Aviom with some industrial Velcro on the bottom, positioning the switch and jack pointing up.
Next time I would do a better job cutting out the cover holes and install the switch so that it toggles to the output side instead of reversed like I have it. I thought about re-wiring it but figured if the church wants me to build 5 more I will fix it then. :)
Update: Inside wiring picture can be found here.
