# LM358 Distortion Reduction

I have been forced to use only the lm358 as my op-amp choice for an electronics project. I have tried setting up a simple inverting pre-amp..using a 10k and 30k resistor. i am feeding a stable 9v to the op-amp.

It is incredibly distorted! Whatever song/sound i feed to it becomes incredibly distorted. my input signal is set as 5v.

What can I do to reduce the distortion? Btw, when nothing is playing in the sound input, there is no noise so it is clean signal to begin with..

• Any chance of an oscilloscope photo of the output waveform? Also : is your input signal 5Vp-p or 5Vrms? Also, what is the gain of your amplifier? – Brian Drummond Mar 21 '13 at 16:15
• Please share a schematic including component values used. A picture is much easier to grasp at a glance, than any verbal description, and will lead to more considered responses. – Anindo Ghosh Mar 21 '13 at 16:16
• The LM358 isn't a great part for audio, but it should not result in incredible distortion either. You should post an image of your schematic with this type of question. You probably have incorrect biasing, but without a schematic, people can only guess. On a single supply, you have to take special steps. You need to generate a V/2 reference voltage, and shift your input signal to that DC level via a coupling capacitor. The output also has to be capacitively coupled, unless the next device expects a V/2 DC bias. – Kaz Mar 22 '13 at 0:08

• Also, input common mode voltage range is V+ − 2 Volts, output voltage range is V+ - 4 Volts, exacerbating the clipping on output. – Anindo Ghosh Mar 21 '13 at 16:24