Question about dual op amps

[Guitarist335]

I read somewhere that when using a dual op amp and only using one amp of it, that you can disable one amp by shorting it.  How is this done? 

Thank you

[patrick398]

Rather than not using it you may as well use it to buffer vref. Probably not needed in a lot of circuits but it's there so you may as well use it

[Guitarist335]

Sorry...but I don't know what buffering means in this context.

I was also wondering why dual amps are normally used in a stompbox circuit.

Sorry- i am a newbie in learning mode.

[antonis]

>I was also wondering why dual amps are normally used in a stompbox circuit.<

Cause their use it's more convenient for any pedal utilizing at least two stages..

[patrick398]

Sorry...but I don't know what buffering means in this context.

I was also wondering why dual amps are normally used in a stompbox circuit.

Sorry- i am a newbie in learning mode.

Yes the price difference is virtually non existent so i do t really bother with single opamps. Buffering vref means using one half of the op amp set up as a unity gain buffer (aka voltage follower). The other half of the op amp you'll be using for amplification or something and it requires biasing at half supply so your input signal can be amplified and it's ability to swing positive and negative are preserved. Buffering the reference voltage stops it sagging under heavy load. I think it's way more complicated than that, but that's my simplistic understanding

[patrick398]

Here is a good resource for info on opamps as well as all kinds of other stuff:
https://www.electronics-tutorials.ws/opamp/opamp_1.html

[ElectricDruid]

I read somewhere that when using a dual op amp and only using one amp of it, that you can disable one amp by shorting it.  How is this done? 

Just as Antonis showed! Short the output to the -ve input (making a "buffer" or "voltage follower") and then shorting the +ve input to ground To 'proper ground' if you've got a bipolar supply, or 'virtual ground' AKA Vref/Vbias/Vb if you've got a simple single supply like in a pedal.

This doesn't exactly "disable" the amp, but rather gives it safely nothing to do (it sits there making sure that its output is at ground).

[antonis]

it sits there making sure that its output is at ground.

More like "wishing" instead of "making sure"..

[ElectricDruid]

it sits there making sure that its output is at ground.

More like "wishing" instead of "making sure"..

I think trying to draw that distinction is an example of Greek Philosophy, Antonis!!

[Marcos - Munky]

Also, another reason to use a dual opamp when the circuit calls for a single opamp is the layout. for some circuits, it's easier to draw a layout using a dual opamp.