Op Amp Summing Amplifier | Operational Amplifier Virtual Earth Mixer

How to use the inverting operational amplifier circuit as a summing amplifier or audio mixer. This configuration is often known as a virtual earth mixer.
The inverting operational amplifier or op amp circuit has a virtual earth point and this can be used to enable a variety of signals to be summed or added together.
The virtual earth mixer or virtual earth summing amplifier using op amps has been widely used in many applications including audio mixers, analogue computers as an adding or summation block, and in any area where analogue voltages need to be added together or summed.
The video provides the equation or formula needed to calculate the gain of each input.
The inverting amplifier summing amplifier is ideal for many applications, but some precautions need to be remembered when using it. Several hints and tips are given that have been gained from practical experience as a design engineer.
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[@MSTheDev]

Answer to all my questions that the 10 previous videos failed to answer. Right here, Thanks!

[@ElectronicsNotes]

Glad to help!

[@howzaboutknow4189]

Thank you, your explanation for setting voltage gain was what I needed.

[@ElectronicsNotes]

Really pleased we were able to help. Thanks for the comment.

[@N4ppul4]

Thanks, I already knew how it works and all, but I needed the quick reminder of how it really worked. This video helped a lot, thanks!

[@ElectronicsNotes]

I'm glad the video helped.

[@samsami9014]

thanks alot for your effort dear, very useful, keep doing electronics design calculations, i will do my best to invite more audience to this channel

[@muhammadfahimi2919]

please do about comparator and intergrator. nice video bro, i always push like button hehehe

[@ElectronicsNotes]

Glad you like the video - I will have to think about a video on the comparator. Thanks for the idea though.

[@oldmossystone]

@ElectronicsNotes do you have any information or advice on how to understand how this circuit behaves when the op-amp clips, and how to 'do the math' in that context?
I assume that if the amp clips, then the virtual ground voltage will swing away from ground, so there will be some combination of 'correct' virtual ground behaviour and the simple passive mixer behaviour, but I'd like to understand the details.

[@ElectronicsNotes]

It is difficult to make an exact diagnosis without actually seeing the physical circuit. You could be driving the voltage into the rails, or you could have a load on the output that is too low in impedance and the op-amp can’t drive sufficient current.
Hope this helps.

[@oldmossystone]

@@ElectronicsNotes Thanks for the reply. I have nothing to diagnose. I want to build a digital model of virtual ground mixer that behaves accurately when it is pushed into saturation. But I'm having trouble finding information, because everything I find starts by assuming that we will avoid saturation in order to simplify the analysis.

[@chrisroberts2266]

its funny because the picture of the mixer faders is actually a yamaha LS9 digital mixer with no opamps in sight of the summing

[@ElectronicsNotes]

It was there to illustrate a point about faders, but yes it is rather too digital. I could not resist the photo though as it looked rather good when I took it.

[@chrisroberts2266]

@@ElectronicsNotes its a nice little video! thank you for making it.

[@ElectronicsNotes]

Trying to create a few more on the same vein so, but have a few others in different topics in the pipeline as well.