LTSPICE THD Analyzer

[Eugene Dvoskin]

Originally Posted by studiostevus

I am a beginner in LTSpice and tried to get this to work... unfortunately the log file shows the measurements FAIL'ed.... any ideas what could be wrong?

Can you submit your schematic? The best way is to zip content of the whole directory, where schematic is located. It is hard to say without loking at your simulations.

[studiostevus]

This is the schematic and the files.... thanks for you help!

Archive.zip

[Eugene Dvoskin]

Hello,
You have to place analyzer symbol on your schematic and connect it's output to your amplifier input and analyzer input to amplifier output. The same way as if you are using real measuring equipment.
I modified your schematic. It is in zip file, together with 2 plot setting file (*.plt), that you may use to display frequency or amplitude sweep results. You can also see control file example for amplitude sweep.
Pictures show transient plots for amplitude sweep and distortion plots for your circuit, frequency and amplitude sweeps.

Don't hesitate to ask any questions.

Eugene.