The KAT Groundbreaker Hum Eliminator

The new Groundbreaker from Knight Audio Technologies (KAT) is a fully transformer-coupled ground (earth) isolating interface that eliminates unwanted hum and noise caused by system ground loops. It is suitable for studio and live environments and is configured to accept both balanced and unbalanced signals. If your amplifier is exhibiting ground loop hum, simply connect a Groundbreaker to the amp’s input via a patch cable then connect the output of your effects chain, delay, chorus or treble booster pedal to the input of the unit.

Although similar products have been available (e.g. from Mike Hill Services) for some time, this unit is priced competitively at £64.50 recognising that multiple units will be required to fully eliminate ground loop hum depending on the configuration of the guitar rig. If you have read my other blog posts highlighting new and forthcoming KAT products then you will already appreciate that every KAT product is backed by Nigel Knight’s expertise as an electronics designer and many years of experience building and maintaining equipment for Brian May of Queen. This product works well in one, two and three amplifier outfits or when connecting mains powered effects (e.g. a Boss CE-1 Stereo Chorus pedal); eight examples of which are illustrated in the diagrams below.


  • 1/4″ TRS (tip, ring and sleeve) input and output jacks allow for balanced or un-balanced signals
  • High impedance input to maintain signal clarity
  • Fully passive, requires no power source
  • Uses bespoke mu-metal shielded high quality transformer for sonic transparency
  • Housed in a rugged solid steel enclosure