2channel audio mixer or switch with automatic src selection

Hi,

I want to build an 2 stereo channels switch with automatic selection of an primary source. So, if on ch1 is a signal it is routed, if not, channel 2 is routed to output.

Can someone give me a link or some basic idea how to do this....

Maybe a good quality mixer is possible, too (If it is not to expensive).

Bye Dan

audio mixer

hi,

the audio mixer you can make, there are lots of mixer circuits in the net like at the http://www.discovercircuits.com

as to your auto selector, i dont get your conceive idea. you said if there is a signal in chan. 1 it is routed to the amp, if none, chan. 2 is routed.

what you really mean is, any signal that is inttroduced to the mixer regardless of which channel it appears will be sense by a circuit and rout it to the amp. that's a neat idea. am interested with whatever replies or ideas will be given :wink:

what is needed here is a random signal sensor that samples all inputs with the presence of a signal. however there could be a problem like what would happen in case a another signal is introduce while there is an ongoing signal coming in :shock:

I think we really need more information, such as exactly what you are trying to do? - and why?.

If you want a switched source, it's not a mixer - and if you want a mixer, it's not a switched source.

Tell us exactly what you want to do, and we can probably make suggestions.

As for actually detecting audio, that's simple enough - just use a full-wave rectifier, just as you would for a VU meter. The tricky part is getting the timing correct, it needs to work like a PPM meter - with a quick attack and a slow decay - otherwise it would switch channels in between words - which, presumably, wouldn't be wanted. Adjustment of the timings would probably be a matter for experiment - you could probably use VOX (voice operated switching) for amateur radio transmitters as a starting point - they face the same critical timing considerations, and usually provide an adjustable delay control.