Audio Mixer Design Enhancement Suggestions

[bbllaannkk]

Hey,

I'm currently involved in an Audio Mixer Design Project in school. Besides the basic design I've attached, we expected to come up with a number of interesting enhancements. Unfortunately, we're only allowed the usage of the 741 op-amps and discrete components only.

I was wandering if I could get your inputs on what sort of enhancements might work with the 741 op-amp.

I've had a look at uV meters and I've heard of an optical crossfader but I haven't found enough information nor schematics to help me out with the design under the limitations mentioned above.

Can anyone help me with this? I'd really like specific details or guidance with the suggested options if its not too much trouble.

Thanks, Looking forward to your ideas!

 

[betwixt]

I can't suggest anything other than more and inputs and a monitor facility but I can tell you the input resistors need to be higher in value and a 741 will not drive an 8Ω load!

The present design does not allow the input levels to be set and most 'pro' mixers will use another channel just to drive headphones so the individual inputs can be checked independently of the main mixer channel.

The 741 is a horrible choice of amplifier but if it's all you have, it will have to do.

Brian.

 

[FvM]

Besides the points betwixt has mentioned, I think that the "graphic equalizer" doesn't deserve the name. It's O.K.
to have a bass/mid/treble control, call it graphic or not, but it should absolutely have a neutral mid position with
linear frequency characteristic. This is not the case with the present circuit.

 

[hsshah]

here is a simple audio mixer design that was practically tested as well and simulation was done in ADS
Technology World: Audio Mixer in ADS