Going to build this from the learning page

[Plento]

Hello! has anyone seen this before? https://www.learningelectronics.net/circuits/4-channel-portable-audio-mixer.html
Looks like a really cool project and I was wondering if anyone has seen/ built it before. If so, I could defiantly use some tips/ pointers.
Sorry if this thread is off topic or not related Im brand new. Thank you!

 

[Tony Stewart]

look up 9V gyrator graphic equalizer .. I think it's better for tone control and simplicity. then analog mixer. otherwise ok but lots of parts

https://www.google.ca/search?q=9V+g...We3oMKHWUGCxEQ_AUICSgB&biw=1024&bih=653&dpr=2

 

[Plento]

look up 9V gyrator graphic equalizer .. I think it's better for tone control and simplicity. then analog mixer. otherwise ok but lots of parts

https://www.google.ca/search?q=9V+g...We3oMKHWUGCxEQ_AUICSgB&biw=1024&bih=653&dpr=2

Oh ok, so you saying I can use the gyrator circuit as the input and tone portion? And yeah it is alot of parts lol

 

[Nigel Goodwin]

Oh ok, so you saying I can use the gyrator circuit as the input and tone portion? And yeah it is alot of parts lol

I'm not quite sure what he means?, gyrators are used in graphic equalisers, and such a design would be a lot more complicated than this simple baxandall tone control circuit (which is pretty well what's used in every commercial mixer design).

 

[audioguru]

I never used tone controls. They are needed when the speakers or acoustics are awful. Turn down the boomy bass or shrieking highs. Turn up the mids so the voices can be heard. Feedback? Then turn down all the tone controls.

The old circuit uses very old low power opamps that are not designed for hifi. I used TL06x opamps about 35 years ago. They are very noisy (rumble and hiss) and since the operating current is as low as an awful LM324 and LM358 then they might have the same crossover distortion (distortion is not mentioned on the TL06x datasheet). This old circuit uses low noise input transistors so that the noise from the opamps is less. Why not use modern hifi opamps without the added transistors instead?

 

[Nigel Goodwin]

I never used tone controls. They are needed when the speakers or acoustics are awful.

They are SERIOUSLY needed on a mixer, and even on a decent HiFi they make good sense - but on a mixer they are absolutely essential - a mixer is essentially a musical instrument, and the tone controls are an important part of it's operation.

 

[Plento]

Thanks I think I will find a better design with HIFI op amps

 

[audioguru]

You can use this circuit with modern hifi opamps. The OPA134 single, OPA2134 dual and OPA4134 quad hifi opamps are good and do not cost too much.