Part way through a little project - adding multiple headphone outputs and mic inputs to the existing FM Radio/SD card player system.
Motorcycle or Rally intercoms can all be bought off the shelf, for a price.
I'm more interested in tinkering and dismantling/hacking/integrating a few existing components to see what I can come up with. Wireless is overrated IMO - just more things to charge up!
Dotted line is the new unit, double arrows stereo paths, single arrows mono paths.
Green boxes are off the shelf components hacked slightly and integrated, Red - switches, Yellow - built up components etc. Two Microphones will switch in via a relay which also mutes the head unit via push to talk switches. The Amplirider will mix in the Mic signal and can be powered by head unit or intercom box depending which is turned on.
Mic Amps mocked up and tested, currently working out the layout for the case
The Schematic
The principle is to leave the audio route from main Head Unit to speakers and rear headphone jack alone since that works well.Dotted line is the new unit, double arrows stereo paths, single arrows mono paths.
The build
Must clean up the bench!Mic Amps mocked up and tested, currently working out the layout for the case
Layout should work:
Output stage is a modified Behringer HA400 Headphone amplifier,
Input Mic Pre-amp boards from an unbranded Ebay source
Buck/Boost Power supply to provide stable 12v, again Ebay
Biggest expected challenge to be potential ground loop issues and wind noise in the Microphones - can't be any worse than the current drive/passenger 'shouting at each other' mode of communication.
More detail to follow.
Update - This approach was not completed, I invested in a motorcycle intercom and went wireless instead!
Update - This approach was not completed, I invested in a motorcycle intercom and went wireless instead!
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