scarlett 2i4 noise(humm)when connected coming from amp

  • Hi all.this is my first post.i am saving money for kemper in the near future.i seek some help though.yesterday my first audio interface a 2i4 arrived after i installed everything in my old toshiba satellite laptop and turned my 15w solid state marshall on annoying non stop sound coming through my amps speaker.if i disconnect the.interface all is good.what shall i do.
    Thank you all hope this is the right place to ask though.