Help with a RCA audio switch.

Thread Starter

jtavrisov

Joined Jun 2, 2011
29
So as a practical learning tool I want to put together an audio switch that takes one input and switches between two outputs. They will all be those Red/White component connectors. Input will be from a WDTV (line level) and outputs will be to a Home Theater receiver and a headphone amp. I also want this switch to be remote, either wifi/bluetooth controlled from my android phone (prolly very hard/expensive but very cool) or IR (remote controller). As a 3rd option (if the other two are out of my reach or too expensive), I've also thought of running a wire and having a physical switch run about 20ft away from the AV switch. I'd have to run headphone wire anyways so ....

Anyway so I'm trying to get just the switching part designed and I am thoroughly confused. I'm thinking to use something like a CD4066 and a micro controller for the wireless portion.


I'm a bit confused on the input voltage of that switch. I know how to get a nice clean voltage for power from a wall wart but that would give me say a +5v and 0v ground. If I'm understanding this correctly then I would it to be +5v and -5v if my audio signal alternates between the two.
 

Thread Starter

jtavrisov

Joined Jun 2, 2011
29
Okay I've learned a couple of ways to split a voltage source into +/-, but I'm still very confused.

I'd like to combine the entire project together into 1. That is that I'd like to power the switch ( decided on the CD4052), microcontroller (prolly ATMega), and the amp (Cmoy design). Havent even begun to think about the IR portion.

This has really confused me on just the power circuit. What the best way to power all 3 of these in one design. The Cmoy calls for a virtual ground circuit, do I tie the micro's GND output to that same virtual ground?
 

wayneh

Joined Sep 9, 2010
17,496
....that takes one input and switches between two outputs.
You do know that a Y connector can split the signal don't you? A switch is not required to achieve this function. I understand wanting to build something, but simplicity is a valid design goal.
 

Thread Starter

jtavrisov

Joined Jun 2, 2011
29
but that would just give both sources the signal.

So my headphones and speakers will be playing at the same time. Right?
 

wayneh

Joined Sep 9, 2010
17,496
but that would just give both sources the signal.

So my headphones and speakers will be playing at the same time. Right?
Maybe, but I can't answer accurately without understanding your system. IF there are two independent audio amps, each of which can receive a line-level signal from your splitter, then yes you can have two powered speaker systems using the same (split) input. But if you want your receiver (or whatever audio amp) to power both speakers and headphones at the same time, that ability is limited by the capabilities of your amp.
 

Thread Starter

jtavrisov

Joined Jun 2, 2011
29
Its a simple multimedia streamer that outputs a line-level signal. I want that output to go to either a Home Theater receiver or my headphones. A simple mechanical switch will accomplish this quite easy but I don't want a physical switch but rather use an IR remote (I'd actually prefer bluetooth but that's much to expensive).


Since the original source is not strong enough to drive headphones, I wish to add in a simple op-amp based headphone amp.


So my goal is to design a IR capable AV switch with a integrated headphone amp for one of its outputs. My (current) problem is designing a power system for all of these components (Analog switch, microcontroller, IR receiver, and amplifier).


I've been ready to give up on this though. It seems like way to much to bite off for my first real project. Maybe I should at least finish my basic circuit theory class first lol
 
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