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Opamp audio mixer circuit question

diy didi

Member
Good day.
I want to build the attached circuit. I want to minimize component count a little as this is part of a bigger project.
Are the input capacitors really necessary?
These inputs will only be connected to other audio sources such as an ipad or mixer.
Thank you in advance.
 

Attachments

Nigel Goodwin

Super Moderator
Most Helpful Member
You're still giving no information?, does it work by magic?, is there no kind of power to it?.

If the top of the pots go directly to jack sockets, then you need capacitors between the sockets and the pots, as you've no idea what's connecting to them.

Likewise, it's sensible to keep the capacitors already in the circuit, as they do no harm, and depending on the entire circuit (which we don't know) may be essential.
 

audioguru

Well-Known Member
Most Helpful Member
Your opamp has no very important power supply. Since the (+) input connects to ground then the power supply must have plus and minus voltages.
Then if the input signals have no DC on them, the input capacitors are not needed.
 

Ramussons

Active Member
Your opamp has no very important power supply. Since the (+) input connects to ground then the power supply must have plus and minus voltages.
Then if the input signals have no DC on them, the input capacitors are not needed.
Similarly, the Output Capacitor is also not required.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Similarly, the Output Capacitor is also not required.
I would disagree, the major reasons for the output capacitor are to prevent the mixer sending DC out to what it feeds, but also to prevent DC coming back in from what it feeds. This is also why I said it was essential to have capacitors between input sockets and pots, in case it's connected to badly manufcatured units without output capacitors.
 

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