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need help with audio mixer? Answered

Hello . im going to make this mixer circuit.Im not sure if it work fine or not.Can you please check it for me ? Thank!

In this schematic, i use R1=R2=47k Ohms , can i use a lower value like 10k or 4.7k ?


Jack A Lopez

Best Answer 7 years ago

I think R1 and R2 are there to limit the current flowing into input1 and input2  respectively. 

Notice that it is possible to move the wipers on both those 10K pots to ground, and that is the case when the largest input current would be possible, and in that case only thing limiting current on input1 and input2 would be R1 and R2

That being said, I think 47K is more than enough resistance, and you could make R1 = R2 much smaller.  10K or 4.7K sounds good to me.

There are lots of possibilities for an signal adding network that will work.  Like that circuit you posted yesterday:
I thought that one was good too.


7 years ago

There's a serious problem with your schematic--the resistors that limit the interaction / crosstalk between the inputs (R1 & R2) need to be after the POTs.

Why? Because when either POT is turned all the way to GND, it will ground both inputs, silencing them.


7 years ago

An inverting amplifier is the best way to do this. Here's a barebones mixer