Mic and Line inputs

[Rspiaudio2017]

I was able to record an audio line input using the attached adapter

When I connected a stereo condenser mics 3.5mm plug into to the attached adapter, nothing happened, the mics uses 2-9 volts, and my understanding the Octo Sound Card uses 3 volts

I tried three different mics all have stereo 3.5mm male, all didn't record audio

Did anyone had the same problem and was able to solve it

Or kindly direct me to a trouble shooting procedure so that I know what I am doing wrong

Thank you

41cMu9-VmAL.jpg (24.69 KiB) Viewed 1939 times

[flatmax]

Oh - I see, hmmm ...

The RCA breakouts don't provide any balanced line power.

You could create your own connectors with passive filters. The headers on the octo board provide 5V power.
You can see the headers in the kicad product here :
https://github.com/flatmax/AudioInjector.Octo.RCA

I have put the pdf of the schematic up there :
https://github.com/flatmax/AudioInjecto ... CA.sch.pdf

You can see on the ADC header, the V5 and AGND lines. The V5 is 5v from the AGND (ground) line. You could hook up a 2.5v linear regulator across those lines and build your own passive electronics to filter and implement what you need. Can you use that in any way ?

Alternatively, there is the preamp which is bundled with the balanced breakouts, which supply a DC offset of +6V. The preamp needs to be powered by a 15v to 20v DC supply. It allows the signal to wiggle about the +6V DC offset. This is the type of thing you are after.

Do you want to build your own electronics ?

thanks
Matt