hi guy
can anyone tell me how to turn a dual op amp into a single chanel op amp ?
thank you
>pic related btw.
>>948645
This is a dumb question. Connect one op-amp as usual, connect both inputs on the other op-amp to GND.
>>948645
Leave the unneeded opamp unconnected.
Or better, connect its OUT to IN(-) and IN(+) to ground.
>>948650
i'd like to bridge them to have more power.
>>948652
Send your signal through one of them configured as a buffer amp, and the other configured as a gain stage.
>>948667
>i'm just trying to get the maximum out of it.
you don't need two
you just need one
if you configure it properly
>>948667
>any diagram would be helpful, thank you
any information on what you actually want to do would be helpful. there are many ways to configure an opamp. none of them involve bridging together for more power.
>>948671
its for a mic amp
single input
single output
>>948645
bumpity
>>948675
What mic are you using? What are your supply voltages? Are you doing a single ended or split voltage supply? It'll help for impedance matching purposes.
>>948747
>What mic are you using?
regular condenser mic
> split voltage supply?
no
>>948667
>i'm just trying to get the maximum out of it.
Maximum what?
>>948854
>split supply
>No
Come on now...
What voltage are you trying to step this up to?
>>948860
the recommended voltage for the mc4558
you CAN parallel op amps for more current output. It's not as simple as just connecting them together, though.
Here's a dude who paralleled eight dual op amps for a low power amp: http://www.head-fi.org/t/568055/5532-parallel-headphone-amp
>>948645
how can i use both to get twice the gain ?
>>949005
The gain of each amp is limited by the slew rate, but is already way more than you need for a mic.
It would make more sense to figure out how much gain you actually need, then configure each of the two amps as a gain stage so that, when combined, they will total the amount of gain that you actually need. Using two amps with lower gain will result in a lower THD.
>>948665
Can you use the opamp to raise the voltage and then connect it's output to the base of a power transistor of some kind?
>>948666
By the way, if you use them like this, can you make an amplifier for a pH probe using a single dual op amp?
>>949044
One opamp is enough for buffering a pH probe, but you need a good opamp for that job and two shit amplifiers aren't going to replace one good amp.
>>948652
then use a power opamp.
lm386 or a tdavariant.
1W lm386's are cheap.
>>948652
then use a power opamp.
lm386 or a TDA variant.
lm386 go up to 1W in a dip8 if i remember correctly.
i got 20W TDA's in pentawatt packages for next to nothing on ebay.
shop around.
>>948652
They don't work that way. They have a push-pull output stage, and they'll fight with each other. The best you could do is connect the outputs through 1-ohm resistors, but now you're wasting power as heat. What you really should do is connect a transistor to the output. Base/gate to output, collector/drain to the inverting input, emitter/source to ground. Or if you need push-pull then you need a complementary pair. Or just get an op-amp with the drive capability you need and not worry about it.
>>948645
like this
>>949044
No, because a pH sensor needs a ridiculously sensitive opamp to get any reading at all out of it. Someone actually asked this on here before and I answered. The opamp specced for his sensor had a rated offset current in the femtoamp range. Several orders of magnitude below your average CMOS opamp.
>>951442
thanks anon
