At Source

• 1). Turn the amplifier on. Adjust the volume dial. If the hum gets louder as you turn the volume up, this is a sign that the hum is coming from a faulty preamp tube. If the hum remains constant regardless of volume, this suggests that the cause is located after the preamp, for example, a faulty output transformer. If the hum is not affected by adjusting the volume dial, take your guitar to a qualified professional for inspection and repair.
  
  
• 2). Turn the amplifier off. Leave it for 10 minutes so the tubes cool down.
  
  
• 3). Unscrew the back panel. Starting on the far left, replace the first preamp tube with a brand new one. Turn the amp on. If the hum is still there, the original tube you replaced was not the cause.
  
  
• 4). Turn off the amp. Remove the replacement. Put the old tube back in. Remove the second tube along and replace it. Continue this process until you remove the tube that is causing the hum. Once you've removed that tube and replaced it with a new one, the hum will be filtered out.
  
  

After Recording

• 1
  If you've already recorded a humming amp, use equalization to filter out.Thinkstock Images/Comstock/Getty Images
  
  Click "S" on the guitar channel to isolate the guitar recording. This mutes everything else so all you hear is guitar.
  
  
• 2). Click "Tools" and select "Equalization." This tool enables you to boost and cut selected frequencies. Fortunately, the hum of a guitar amplifier typically fills a narrow frequency band, so cutting it should not affect the sound of the guitar.
  
  
• 3). Hit "Play" and click on the frequency curve on the equalizer grid interface. This grid is called a spectrum analyzer. It lets you manipulate the frequency curve to isolate bad frequencies.
  
  
• 4). Drag the curve up and down the vertical axis and across the horizontal axis. The vertical axis represents gain and the horizontal axis represents frequency. As soon as you bring the hum frequency up, it will become loud and prominent in relation to the guitar. Stop moving the curve as soon as this happens. Make a note of the frequency band as indicated in the dialog box on the grid interface.
  
  
• 5). Slide the gain dial for the rogue frequency down to zero. This mutes the frequency band upon which the hum exists, removing it from the audio.