Hello can some one please help me find a fully functional finished working audio op amp circuit with microphone & speaker on flying leads please so i can put a microphone @ the window the hear nature during the day & or bugs @ night. I'd like to move it around the house, hence flying leads 10m plus would be good.
I have built up Afrotechmods circuit which works on a LM358, but can only get a few metres on the speaker end & 1m on the elec mic end, & then it sounds like a water fall in the back ground which is what audioguru said would happen.
Audiojuru suggested to use a OPA134, i will order this from Element14 if i have to, but would any of these chip do from Jaycar Electronics which i can source easily.

Thank you.
Ernie H.

 

Use a dual stage on the Lm358 with a fet transistor microphone, feed it into a power amp..

 

Use a dual stage on the Lm358 with a fet transistor microphone, feed it into a power amp..

View attachment 196049

Hi Dodgydave, thank you for this circuit, more than happy to build this circuit up, i will save this in a project folder, is this called a preamp section? what happen now, do it connect this up to an pin3 on the LM358? I'm a fish out of water now, i simply don't know what the next stage is... what is the next part of the circuit please if u could help me again please.

Thank you.
ErnieH

 

Yes C2 is the Input to your LM358 chip...take the output from the Lm358 or feed it into an Audio amp chip..

 

Yes C2 is the Input to your LM358 chip...take the output from the Lm358 or feed it into an Audio amp chip..

Ok Thanks 4 that Dave, i'll try 1st attaching your circuit 2 my small LM358 circuit i've already made, but, I can see its time 2 enter the world of a pwr amp, if i want 2 extend the speaker cable 2 get some distance away from the mic.

ErnieH