switchbox

I constructed this retro looking switchbox as a weekend project.

It is essentially a 2X2 passive matrix switcher.

input section:

• 2 x RCA linked
• 2 x 6.3 TRS jack: 1 stereo or L and R mono 
• 1 x stereo 3.5mm

All connectors are linked.

output section 1

• RCA pre attenuator
• RCA attenuated
• 2X TRS 6.3mm attenuated: 1 stereo or L and R mono
• 3.5mm stereo attenuated

output section 2

• same as 1 but no attenuator

For each output section you can select input 1 or 2. The output section allows you to select

• left ch only (right mute)
• left to both
• stereo
• reverse stereo
• right to both
• right ch only (left mute)

The attenuator is used as a volume control for my computer speakers, much better than reaching for the mouse to set the volume. The attenuator is a huge compromise, in theory it is heresy to use such an unbuffered high value for the potmeter.  Driving a long cable from a high source impedance causes HF roll-off, however cable lengths to the active speakers will not exceed 1m so this will not be a problem.

Holes, holes and more holes

Check that everything fits

Prepare for a serous wiring job.

A word about the wiring, I used unscreened wiring since the box is realy well screened and we only deal with line levels. It looks wild but do not be temped to tie  the wires together as this will introduce cross talk. Use screened wire if you want to do tidy wiring!