Hi there, Martin.
The standard approach is to use an audio isolation transformer. I=20
have had very good success with issues such as what you are describing.
Shameless plug: my company sells little isolation transformer modules=20
for not much money. These use a semi-custom transformer from=20
Datatronics and really do work very well. I think that cost is=20
around Can $25 in singles (soon to increase due to supplier cost=20
increases) plus shipping.
Let me know if you want to try this out. I'll arrange to send one to=20
you and you can either pay for it or return it as you see fit.
dwayne
At 09:06 PM 11/14/2018, Martin McCormick wrote:
> Are there any optoisolators that are suitable to carry
>analog audio over the normal frequency range of 20 to 20000 HZ?
>
> What I am trying to do is feed audio from a radio
>receiver across the room to an audio mixer. There are enough
>computers and switching power supplies in the room that noise is
>picked up by the shield of the audio line and ends up being
>induced in to the radio via the chassis ground.
>
> If optoisolated, the noise would still be on the cable
>but the path for it would break completely at the output side of
>the isolator.
>
> I am not holding my breath but I figured I can ask
>whether any such device exists or maybe a conventional
>optoisolator will work if one conditions the input to the LED to
>negate the distortion one would get by feeding audio biased to
>light the LED halfway during silence and then go to full
>brightness and almost fully off at maximum volume.
>
> One would hope for linear response.
>
> Thanks for any good ideas.
>
>Martin McCormick WB5AGZ
--=20
Dwayne Reid
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free
www.trinity-electronics.com
Custom Electronics Design and Manufacturing
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.