Pre amp

139

01:34:44

I made this with 2 741 op amps using a 1M pot for negative feedback on the 2nd 741 and an input resistor of 100 ohms.
This works effectively. 

published 11 years ago

hurz

11 years ago

Lower cut off frequency is about 250Hz. For audio it suppose to be the -3dB point at around 20Hz. Use the bodeplot feature to check that. Output current 60mA is a little to high for 741. Should not exceed 20mA. Virtual gournd at 4.5V should be with an additional cap to not get ground noise into your signal path. 2 OpAmps is probably one to much, you could do it with just one non inverinting one, when it was your intention to NOT have 180degree phase rotation. And the layout could be imporved a lot ;-) Keep it up please!

hurz

11 years ago

One more thing, the output configuration of OpAmps should be addapted to min 0V and max 9V. And you will notice 1V peak is to much and has to be lowered to about 500mV.

nickbass

11 years ago

Thanks hurz

hurz

11 years ago

You are welcome!

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