this is my first post here. We use KiCad 5.1.12 at school but I also have the exact same problem in 8.0.6
The following push-pull amplifier simulation works well in DC and Transient analysis, I cannot perform an AC analysis (Bode) in which i receive a spice message:
doAnalyses: matrix is singular
run simulation(s) aborted
I’ve tried setting initial values to capacitors, setting another component and input Vgen and
a ton of other methods, nothing works.
I finally got it working by changing the transistor devices to generic NPN_CBE and PNP_CBE with the same spice LIBs. This is odd, since the dc and transient simulations worked fine with the previous model.
Anyway, I learned my lesson, BJTs to be used now are the above CBE ones, so they are both compatible with the .LIB model and the ac simulatorsl.