Clean output power testing with an oscilloscope and guitar 

Hey, how did you hook this up? I’m trying to do a frequency analysis on my fender, twin reverb. I put some new speakers in it, and I use a variety of different guitars, such as Gibson, ES 335, and fender Stratocaster. Trying to learn more about my gear and have been researching oscilloscopes. Are you using a microphone or are you directly wired?