Opamp circuit DC offset

[diydidi]

Good day all
I have built this circuit as part of a little audio mixer.
Im getting a 200mV DC on the output pin. Opamp is not oscillating at all, actually perfectly clean DC.
I have tried different bipolar and JFET opamps.
This is a dual opamp and both sections have the same resistors.
I also tried a resistor on pins3/5. No difference.
Can anyone help? thanks!

[dmeek]

Instead of connecting pin 3 directly to ground, use a 1K resistor or a resistor equal to the input resistor going to pin 2.

To be more precise the resistor should be equal to the paralleled resistance of the input and feedback resistors

[Jazz P Bass]

That circuit is an inverting amplifier.

If you have ANY voltage across R1 (1K), then that voltage will be 'amplified' by the gain of the circuit . (47K/1K).

[Dave H]

I have built this circuit as part of a little audio mixer.
Im getting a 200mV DC on the output pin.

What is the input connected to? If it's DC coupled to a low impedance source the op-amp will have a gain of 48 to its own input offset voltage which will turn a 4mV input offset voltage to 200mV at the output.

[J M Fahey]

^^^^^ THAT

AND add 10uF in series with input 1k resistor, may be a plain bipolar with the + terminal towards input jack.

As is, it not only has input offset, which is corrected by dmeek´s suggestion, but you also amplify 50X any offset or leak which might be applied to input.

The series cap means DC gain is 1X, so even uncompensated offset would become 200/50=4mV

As a side note, try to upload images as image files (jpg / gif / png) so they can straight be opened inside the page.