This is the circuit I'm trying to build:

Circuit on falstad.com Preview of circuit

I feel like everything works in theory, but I'm having trouble implementing the grounds on the actual circuit. I do not know where to connect the grounds on my circuit.


closed as unclear what you're asking by Andy aka, Edgar Brown, Lior Bilia, Kevin Reid, awjlogan Feb 20 at 12:58

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.


There is no power-supply shown in your schematic diagram. For an op-amp circuit that is required to swing both positive and negative with respect to circuit ground you need a split-rail power supply that has a positive output and a negative output.


simulate this circuit – Schematic created using CircuitLab

Figure 1. A split-rail power supply powering an op-amp.

In this case all your circuit grounds will be connected to the power supply ground.

Your circuit will not work in practice due to the bias currents on the inputs to the two op-amps fed by the AC signal. It needs a DC path to ground.

  • \$\begingroup\$ "Your circuit will not work in practice due to the bias currents on the inputs to the two op-amps fed by the AC signal. It needs a DC path to ground." Would this concept also apply to the LED's I have in the circuit? \$\endgroup\$ – Stiefel Alex Feb 18 at 20:22
  • \$\begingroup\$ Your circuit shows signs of haphazard design. Nothing is numbered so we can't discuss the problems but you have three op-amps acting as unnecessary unity-gain buffers and four more with their outputs shorted together. Your question doesn't specify what you are trying to do but I suspect it's a sort of signal strength meter. I suggest that you strip back your circuit to get one LED to work and take it from there. You can edit your question to add in new schematics as you go. Show the power rails, etc. There's a CircuitLab button on the editor toolbar. The results will look more professional. \$\endgroup\$ – Transistor Feb 18 at 20:41
  • \$\begingroup\$ I did not realize there was a CircuitLab button. I'm in a class, and falstad.com is the online resource the professor recommended. I will remake my circuit with the removal of the buffer op amps. The op amps in the bottom right are supposed to be in parallel, and connected to a 8 ohm resistor to represent a speaker. you are correct in saying that the LEDs are a indicator. \$\endgroup\$ – Stiefel Alex Feb 18 at 21:04
  • \$\begingroup\$ That was the problem with my circuit. I wired my split rail power supply incorrectly. \$\endgroup\$ – Stiefel Alex Feb 25 at 18:19

Not the answer you're looking for? Browse other questions tagged or ask your own question.