Please ensure Javascript is enabled for purposes of website accessibility Jump to content

Tube Troubleshooting and Replacement


Q: Is Biasing covered under warranty?

A: Typically not. It should be considered as part of the routine maintenance in keeping your amplifier at its peak performance. However, if re-biasing is required as part of other warranty service, it will be covered under the warranty policy.


Q: My tubes are not working (i.e. not lighting up, no output, etc).

A: Check the following:

  • Make sure the tube is firmly seated in the tube socket

Other tube situations:

  • My tubes make a popping sound accompanied by intermittent light from tubes - the tube is failing and needs to be replaced.
  • The appearance of 'white frost' inside the tube -  the tube has cracked and it must be replaced.

General Guideline for Replacing Tubes: Always replace power amp tubes with matched set(s) every 12-24 months depending on the amount of use, and have the bias checked and/ or adjusted by an Authorized Line 6 Service Center.

  • Preamp tubes (such as the two 12AX7s) only need to be replaced when they are microphonic (ringing sound from tubes when tapped), noisy, or damaged.

  • Create New...