Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

LTSPICE opamp circuit sim

Status
Not open for further replies.

potency

New Member
I'm trying to sim the input circuit of an audio EQ, but I'm getting only DC at the output.

This is what I'm trying to simulate:
PME input.png



It's the input section of this schematic:
PME 4,8-1 cropped.png



Here's what I've created, the .ASC is attached:
Spice circuit.png




I'm using an LT1057 model as it is described as a drop-in replacement for the TL072, and I'm assuming it's enough to get me in the same ballpark for what I'm trying to achieve. I've successfully simmed tube circuits but this is my first go with an opamp. What am I missing? I've tried searching for an explanation of this type of circuit but I haven't been able to find one. Please be gentle on me as we pop my cherry.
 

Attachments

  • PME input 110119.asc
    1.8 KB · Views: 237
There's an error in the original circuit schematic: pins 5 and 6 have been transposed. Pin 5 should be the non-inverting input.
 
You are using the wrong inputs. See picture below.
The signal goes to the (+) and the feed back toes to (-)
1572634804837.png

The first picture in post #1 is wrong. Like many schematics on the internet. (and much of the politics. … wrong and backwards)
 
Thank you both for your help! What's kinda funny is that I got the schem directly from the manufacturer.
 
What's kinda funny is that I got the schem directly from the manufacturer.
It's not unknown for manufacturers to deliberately include errors in their documentation, to detect copyright infringement and deter counterfeiters. In this case, though, it's more likely a simple typo.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top