what to do with the other half of the opamp?

[saxtim]

When you've got a circuit with a dual opamp used as a single (for example the orange squeezer) what do you do witht the second half of the opamp?

I've got pin 4 to ground, pin 8 to the power supply, 1 is the output and 2/3 are inputs.  That leaves 5,6 and 7.  In the PCB I designed for the orange squeezer I simply connected these 3 pins together.  I now wonder after some suggested it in my orange squeezer distortion thread if these pins should also be tied to gound?

So what exactly should I do with them? connect them all together (5,6,7)and then to ground, or some variation on that?

thanks

tim

[Peter Snowberg]

I would connect pins 6 and 7 together and to nothing else and then connect pin 5 to either a Vbias voltage, or to ground. That creates a unity gain follower. You should never connect the output pins to another voltage, if you do the chip will "fight" with that voltage.

Take care,
-Peter

[saxtim]

thanks Peter,

tim

[petemoore]

That clarifies it nicely.
 Always using singles for single OA ckts, recently I've had need to understand this...Thanks, Saxtim for asking and thanks for answering Peter !!

[RickL]

You may also want to use the extra opamp section to build something else in the same enclosure. For the cost of an extra footswitch and a few components you could add a simple booster, an active tone control, an MXR style distortion or a wah type filter. If you don't have room on the board just run three leads from the opamp and a ground wire to a seperate bit of perfboard, you won't even have to wory about power.

[Elektrojänis]

As an addition to what is allready suggested: You might use it as an output buffer... Or use it for making another output that is inverted version of the normal output... (it might be usefull for something some day.