General idea of audio matrix

C

computer

New Member

• Apr 13, 2005

• #1

Hi,

I'm just after a basic understanding of how an audio matrix switcher would work?

I want to design something to take 4 inputs and have 4 outputs for audio (stereo signals). I know you could just do it with 16 (!) relays, but that'll get very expensive and complex quickly. I will use a PIC chip of some sort (don't worry about that now) to control it so I can route any input to any output, or and combination.

However, I'm sure there must be better designs than 16 relay technique! Any ideas?
computer

 

Exo

Active Member

• Apr 13, 2005

• #2

a couple of 4052 ( https://www.fairchildsemi.com/pf/CD/CD4052BC.html ) 4 to 1 multiplexers would do.

1 multiplexer supports 2 channels (gd for stereo). You would need 1 for every input and 1 for every output. (that's 8 cheap IC's)...

We're talking line swiches here btw, not power switches

 

C

computer

New Member

• Apr 24, 2005

• #3

On a similar note, I am looking at building a 8 input/8 output SVideo matrix.

I can do almost all of that with two MAX456's (one for C and one for Y). However do I need drivers after that? Some sort of op-amps or something? The schematics suggest 75Ohm resistors to ground on all inputs, and MAX470's on the outputs, however I can't seem to locate these 470's anymore - is there a direct replacement and are they what I want for SVideo anyway?

 

C

computer

New Member

• Apr 24, 2005

• #4

Also, anyone explain what I need to connect up to use serial control? I'd have thought I'd only need serial in/out but it seems there are latch lines etc.

This will be controlled from a PICAXE-18X.

 

F

FRIED

New Member

• Apr 24, 2005

• #5

There are some here with integral output buffers
**broken link removed**

 

Mike - K8LH

Well-Known Member

• Apr 24, 2005

• #6

You may want to look at the MAX4571 through '4574 audio/video switches in a 28-pin package with 2-wire I2C or 3-wire SPI interface...

Regards, Mike

 

Dr.EM

New Member

• Apr 24, 2005

• #7

Could get yourself a good old fashioned patchbay :wink: :shock:

 

C

computer

New Member

• Apr 24, 2005

• #8

Hmm,
I came across the **broken link removed**. It's a 32x16 matrix video switcher with internal buffers. One of these would allow me to do 16 input, 8 output, S-Video switching as long as I made sure it 'paired' up channels in software.

Although it's a really odd package (which I can't work out what it is)! Is there some sort of adaptor to convert this to DIP?

computer

 

C

computer

New Member

• May 17, 2005

• #9

bringing this back into the light again,

would it be possible to use one of these audio or video matrixes to make a USB matrix switch?

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• May 17, 2005

• #10

computer said:

bringing this back into the light again,

would it be possible to use one of these audio or video matrixes to make a USB matrix switch?

Click to expand...

Yes, use a microcontroller to receive the USB data and control the matrix, but USB isn't simple to do!.

 

C

computer

New Member

• May 17, 2005

• #11

bah I didn't mean that, I meant like, it switched 4 computer's USB between 4 devices, or something? obviously you can't split them and have one device on two computers or anything, but you could write that into the software which controlled the USB. you'd only need 2 lines per 'channel' right? Data + and Data -?

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• May 17, 2005

• #12

computer said:

bah I didn't mean that, I meant like, it switched 4 computer's USB between 4 devices, or something? obviously you can't split them and have one device on two computers or anything, but you could write that into the software which controlled the USB. you'd only need 2 lines per 'channel' right? Data + and Data -?

Click to expand...

Sorry!.

Yes, you should be able to switch USB connections, but, as with any such switching, you need to be sure that the impedance of the switching device is low enough, and that they will happily pass the frequencies involved.

 

C

computer

New Member

• Jun 8, 2005

• #13

would something like the MAX456 switch mono audio or is the impedance not like correct or anything?