I just built an opamp and all i can hear the music CD i played thru it but it makes it quieter and there is a buzz that is louder than the music.

PLEASE HELP

 

For one thing, the opamp is connected as unity gain - that is, the output is looped back to the inverting input.

Another thing is as drawn, the -9v is on the wrong side of two 1 Meg resistors that were meant to provide an artificial reference halfway between the +9 and -9 supplies.

If you want the opamp to actually increase the signal level, it'll need to be wired differently.

What is the amplifier IC that you are using?

 

it is a LM741CN opamp. could you please show me how to rewire it?

 

Have a look through Vol.III Chapter 8: http://www.allaboutcircuits.com/vol_3/chpt_8/index.html

 

The lousy old 741 opamp is 40 years old. It is noisy, has a low bandwidth and its high frequency distortion is bad. It is not good for audio. A TL071 has the same pins and is much better.

What is your opamp driving?
Do you have a shielded audio cable for the input and output?

 

To Audioguru,

Would TL082CP chip work as well as the TL071?

 

Your project would be much easier if you used an LM386 audio amplifier instead.

It's made specifically for such applications.

Download the datasheet from National Semiconductor's website:
http://www.national.com
Link to the LM386 page:
http://www.national.com/mpf/LM/LM386.html
Direct link to datasheet:
http://www.national.com/ds.cgi/LM/LM386.pdf

 

Ok, so i tried the exact same circuit just with the LM386 opamp it workd better, but it still is not making it louder it is making it a little bit quieter and it is distorting no matter what volume i have it at.

Please Help

 

Try this wiring setup with LM386. It worked well for me, for amplifing low sounds on a portable dvd player.
http://www.softwareforeducation.com/electronics/Circuits/LM386.htm

 

The LM741 is an opamp
The LM386 is a power amplifier.
They are completely different so they cannot use the same circuit. Circuits for the LM386 are on its datasheet.
An opamp can drive a 2000 ohms or higher load. A power amp can drive a load down to 8 ohms.

The TL071 is a single opamp that is a TL081 selected for low noise. The TL082 is a dual opamp with its pins numbers completely different. The TL072 is a dual opamp and is a TL082 selected for low noise.

 

I didn't mean for you to use the exact same wiring.

You need to read the datasheet and follow the application guidelines. It's all spelled out for you right there.

 

Try this for size have a look at page 6.

http://www.national.com/ds/LM/LM386.pdf