## Powering opamp with 9v?

All frequent questions about ICs of all kinds, will be stored here.

### Powering opamp with 9v?

Almost every circuit I have looked (if not all of them) have their opamps powered with 4.5v by a voltage divider.

Is there a problem by powering the opamp with 9v?
I mean, for higher thresholds feedback loop diodes (like an LED) it would be better to have 9v on the opamp right? To achieve more "signal boost" and then reaching the led clipping.

Am I right or this does not work?

Frank
FrankKair

Posts: 10
Joined: 14 Oct 2009, 14:39
Has thanked: 5 times
Have thanks: 0 time

### Re: Powering opamp with 9v?

This thread is a few months old, but in case you haven't gotten an answer elsewhere:

If you look at the schematics again, I think you'll find that usually the op-amps are indeed powered with 9V in most cases (9V attached to V++ pin and ground attached to V-- pin). The voltage divider you see is usually connected to the non-inverting input. This serves to center the signal between V++ and V-- for maximum headroom. Otherwise the op-amp would clip the negative half of the signal.

V.png
You do not have the required permissions to view the files attached to this post.
induction
Resistor Ronker

Posts: 273
Joined: 07 Feb 2012, 21:47
Has thanked: 61 times
Have thanks: 132 times

### Re: Powering opamp with 9v?

You need to lookat the opamp datasheet, opamps use a bipolar power supply which in the case of most guitar pedals using a 9v battery this happens by a resistor voltage divider across the 9v supply giving 9v-4.5v- 0v this translates into +4.v - 0v and -4.5v where the Vbias is the 0v. Most opamps can easily work on a +/- 15v so if you already have a voltage divider in the circuit then it is possible to run higher voltages. One important point is to check that the voltage specs of the capacitors are high enough.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

Ice-9
Transistor Tuner

Posts: 1055
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times