Audio matrix - one to many

[Elvis9000]

hello, I am a novice in electronics with a bit of playing around with arduino etc, more a software developer..

I want to build an audio matrix switcher that can switch 1 input to 1 or more (zone) outputs. I've had a Google around and come across the tea6420 ic but very little about it other than people like me trying to get answers on if it is the right chip for the job.

Other suggestions say use 16 double pole relays but if one $3 chip can do th job, 16 relays seems a bit overkill .. People also saying relays 'click' when switching audio

I'm ok with arduino/wifi/software side but just don't know best way to tackle the audio circuit. I can't seem to find anyone that can confirm the tea6420 can do one to many switching, and not sure if I would need other electronics on each side of the chip to maintain the audio signal/quality? I've never dealt with audio electronics before..

Any feedback very much appreciated!!

Looks like this guy wants to do same thing but no replies .. http://www.edaboard.com/thread281691.html

 

[JWHassler]

You're right.... that datasheet comes tantalizingly close to saying what you want, but doesn't actually say it
.
Take a look at the TEA6430 datasheet. It's almost the same thing, but with a bit more explanation.

If it will do one-to-many switching ( which seems like its only reason to be) the sample-circuit in the TEA6430 datasheet is all you need, plus a monster array of RCA jacks

 

[Elvis9000]

Haha, thanks. So you think the 6430 might do the job? My thinking would be you'd send it a byte to say map in 1 to out 1, then send it another byte to map in 1 to out 2, thus have in 1 going to both out 1 & 2?

And before changing to another array, then send a reset..? You think that may make sense? I can't see how else you'd get multi-out otherwise as it doesn't look like it can be defined in the byte you send it.

Did you see something in the 6430 data sheet that eludes to it def been able to do 1 to many? I couldn't see..

I had a friend say there are other mux chips available so not sure if I should keep looking for something that spells it out.. Was going to make a few of these for friends so wanted to get the base chip right before trying to solve the problem with all sorts of other things to find there's a chip that does exactly what's required.

 

[JWHassler]

It looks like a single I2C byte can specify a single one of five routed to a single one of four outputs
If you need to have a single input routed to multiple outputs, you can do it with the TEA6420
The TEA6430 is the same device, but with a disable control.
AND, to further the headachiness, there is a TEA6422, with 6 inputs, 3 outputs.
What are you building?

 

[Elvis9000]

So you reckon the 6420 can do one in to multi out? I couldn't see how you'd send it a byte that defined multi out.. Other than possibly send it a byte for say in 1 to out 1, then send an additional byte for in 1 to out 2 and so on.. Then if you wanted to completely change the selection, reset the chip and send it a different array of bytes..

I don't know if the second byte would override the first mapping, or compliment it and you need to reset the chip to clear the matrix you've virtually built.

I just want to build a simple audio matrix for my house. I have speakers in different rooms (4 dif zones) and want to be able to say input 1 (radio for example) to room 2 and 3.. I know there are commercial solutions but they cost significantly more than a $3 chip and some rca sockets and caps.

+ I wanted to build the mobile phone UI to control it all as that's more where my skill lies.

The multi output though is the key and that's what I can't get a clear understanding on what chip to use and what method to tell the chip to do say in 1 to out 2,3 and 4. I've looked at the 6420 data sheet as well and I don't know if it does.. Can u see something I'm missing?

 

[JWHassler]

Don't think you're missing anything...
Just send it an I2C transmission that names an Input channel, an Output channel, and maybe a Gain ( for 6430 or 6420)
Repeat for every output you want turned on.

It's really hell trying to find these things on the ST website... just found TEA6422, which is, worryingly, marked 'Not Recommended for New Designs'

There're some bumps in the path, sure, but it sounds like a fun project.
Are you going to use Bluetooth or what?

 

[Elvis9000]

Yeah, I was going to put a bt audio module on a couple of ins, or maybe an AirPlay device.. Plenty of prebuilt modules out of China, just the switching is where am hung up on best way to go... I might just buy a couple of 6420s and 6430s and wire up a basic test and see if I can just send it multiple bytes and get in to multi out happening, not exactly huge money if it didn't work...

Just thought I'd put his up here on the forum in case anyone else had done this before and come up with a smart design

I am also interested in doing this on a larger scale maybe 24x24 as a studio patch panel as I play round with audio recording and it would save a whole load of plugging and unplugging cables.. In this scenario I wouldn't need multi out, but it would be a handy piece of kit in a studio .. Again commercial version would be $$$$

 

[Elvis9000]

Thanks for your feedback by the way!!