Low power mic to 2w speaker mono audio circuit design

[Newtopprojects]

Thank you all for the great information.

It seemed that PAM8303 is not recommended for new design. So I had used PAM8304 to draw the following. Will test it these days. It will be appreciated if our experienced friends can take a quick look and advise comments.

Thank you again,

 

[audioguru]

The PAM8303 is not going to be made anymore because nobody uses mono sound anymore, everything is stereo today.
You show all the connections in the PAM8403 on the wrong pins.
You are wiring the preamp with a very complicated balanced input and a balanced output that are not needed.

 

[ChrisP58]

Octopart.com is a website you should know about. Type in a part number and you get real-time stock information at all major vendors.

Findchips.com is a website similar to Octopart. There is a lot of overlap for the major distributors, but they often show different second tier suppliers. That can be an advantage when trying to find stock for odd or discontinued parts

 

[Newtopprojects]

The PAM8303 is not going to be made anymore because nobody uses mono sound anymore, everything is stereo today.
You show all the connections in the PAM8403 on the wrong pins.
You are wiring the preamp with a very complicated balanced input and a balanced output that are not needed.

Hi audioguru,
Thank you so much for your comment and a great catch. I am using the PAM8304 and the input/output pins were messed up (too sleepy).
The microphone will be positioned in front of a small side-way wind tunnel. I was planning on using a uni-directional microphone with differential inputs to the TS472 pre-amp. I had looked at LMV1012 but used TS472 in trying to reduce the background wind noise.
Can you please take another look and advise?
Thank you so much again.

 

[Newtopprojects]

Findchips.com is a website similar to Octopart. There is a lot of overlap for the major distributors, but they often show different second tier suppliers. That can be an advantage when trying to find stock for odd or discontinued parts

Thank you ChrisP58.
I am a bit concerned about the TS472 availability.
Will definitely look into it.

 

[Newtopprojects]

Respectfully calling our great advising members to take a look on the following designs.

Will try them in the next few days after I get the parts.

Developed another design using LMV1012 due to the TS472 availability concerns. No sure about the audio output quality difference between the two?

Thank you all so much!

 

[audioguru]

The tiny LMV1012 preamp is made to go INSIDE a small electret mic to replace the Jfet that is usually used inside.
The input of the LMV1012 must not have a voltage added to it but a normal electret mic must have a voltage to power its Jfet.

Your circuit also has duplicated capacitors and capacitors to prevent interference when the preamp is INSIDE a cell phone.

 

[Newtopprojects]

audioguru The LMV1012 is outside of the mic. I put up the bread board and the speaker output looped back to microphone and created a high pitch noise.

Is there a better way to filter out the high pitch noise? I am looking for a Low-Pass Filter (LPF) to filter out anything above 3 KHz, hopefully to get rid of the high pitch noise.

I have found this circuit but could not find the MF6050 nor its newer successors LMF60 series. Can you please shed some light when you get a chance?

Thank you for your advice.

 

[audioguru]

I put up the bread board and the speaker output looped back to microphone and created a high pitch noise.

Is there a better way to filter out the high pitch noise? I am looking for a Low-Pass Filter (LPF) to filter out anything above 3 KHz, hopefully to get rid of the high pitch noise.

I told you in post#5 "If the mic can hear the speaker then you will have acoustical howling feedback." It can occur at ANY frequency. It cannot be filtered away, The level must be turned way down or the mic and speaker must be far apart to stop the feedback sounds. A good way to prevent feedback sounds is to record it without the speaker then play it back without the mic.

 

[Newtopprojects]

Thank you so much audioguru. We will try your suggestion. Much appreciated.

 

[Newtopprojects]

Teaming up with a friend to develop this circuit. Will update when successfully done. Thank you all for the great advices.