No compatibility mode selected!
warning, can’t find model net-u1-pad4
Circuit: KiCad schematic
Error on line 11 :
u1 nc_01 net-c1-pad2 net-r3-pad1 net-u1-pad4 nc_02 net-c2-pad2 net-u1-pad7 nc_03 lm741
Unable to find definition of model net-u1-pad4
Note: can’t find init file.
** ngspice-34 shared library
** Creation Date: Tue Feb 2 12:29:13 UTC 2021
Error: there aren’t any circuits loaded.
Can’t help you with the simulation but I can see on your schematic; R4 does not connect to U1P6
To me it looks like KiCad’s mouse cursor is over the wire in the screenshot, and I can’t tell what’s underneath it.
I don’t know much about ngSpice in KiCad, but I did run a few simple simulations long ago and it does work. Apart from reading the manual (& tutorial on sourceforge), your errors feel familiar and have been answered multiple times on this forum.
This example works for me:
sallen_key_LVM358.zip (6.2 KB)