How to use only the poweramp of a powered toaster ?

Hello guys , I have a preamp and wanted to test it in a real cab so is there any way to use only the poweramp of the toaster without being through any profile.... Just the poweramp of the toaster I want to use... Thank you....

Thank you , but with this way does it take affect of the profile that is being loaded or from the aux in you bypass the profile that is being loaded ?

thank you so much...