New Sensor has designed and produced the reissue Tung-Sol EL84/6BQ5 tube and it is now in stock. The original Tung-Sol EL84/6BQ5 was a popular OEM power tube for American-made EL84/6BQ5 guitar amplifiers, such as those built by Gibson and Harmony. The manufacturer states that due to its rugged construction and conservative ratings, the reissue Tungsol EL84 vacuum tube is the most reliable current production EL84 tube available for use in Vox AC30 tube amps. Also, it is an ideal replacement for EL84 hi-fi tube audio amplifiers, such as those built by Fisher, Scott, and Harmon-Kardon. Note: These tubes have a slightly larger diameter than other EL84 tubes so they can not be installed into some '90's era Marshall DSL201 or DSL401 amplifiers, some '90's era reissue Vox AC15 amps, and Bad Cat amps.