Friday, March 1, 2013

3.5mm Audio Input/Output Switch Box

This project is to clean up my 3.5mm (1/8") audio mess I have at my desk.  I have a few different sources; eg computer, tv, laptop, phone; and I have a few different devices that I want to output the sound to (headphones, speakers in different positions).  I don't want to keep hooking up all these different sound equipments, so I made a simple audio input/output switch box.

It will have 5x inputs, 5x outputs, and 2x 5 position 2 pole rotary switches.  The idea is that I select one of the inputs (source) with one switch, then select an output (speakers) with the other switch. 

Material List

Wire (I used some cheap stranded wire from Amazon)
10x 3.5mm audio jacks  (digikey: CP5-43502PM-ND)
2x 5 position 2 pole rotary switches  (digikey: CKN6046-ND)
Knobs  (digikey: 226-4084-ND)
Enclosure  (Amazon link)

Already had

Soldering Iron
Helping hand (optional)
Drill (or dremel)

The total cost of this project is around $70 with shipping and tax.

Step 1: Drill Holes

Drill 5 holes on the ends of the enclosure for the 3.5mm jacks and 2 holes on the top of the enclosure for the switches.  I had to use the long sides of the box because the 3.5mm barrel jacks were going to be too close on the short end.


Step 2: Solder the jacks and switches together

Use a piece of tape as an alternative to a helping hand helping hand.

This takes a long time and a helping hand is useful.

The 3.5mm jacks have numbers on the back.

The schematic on Digikey for the switch says that the number 1 lead on the jack goes to 1 on the switch, and the #2 lead on the jack goes to position 6 on the switch. Then for the second jack, the first lead goes on 2, and the second goes to position 7 and so on.

Be careful of the middle leads on the switches.  If you add too much solder they will have a chance to touch some of the other leads.  I put some electrical tape around them just in case.

All of the jacks have to have a common ground.  Solder all of the ground wires together.

Step 3: Test / Shove hydra in box

Test each jack and switch before assembling to save some potentially lost time.

Try not to be too forceful in case the solder joints come off. 

Enjoy organized audio input/output switcher box

Final Comments:
This is not audiophile grade.  I was going more for practicality than looks.

Next one of these might be in a bigger enclosure with an amp :D

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