heat sinks attached to the plates keep this one from "sagging" at full power and so keep the bass tight and treble crisp. The 1st choice of Matchless and many pro players including Billy Gibbons, Joe Perry and Joe Walsh  (less)

are used by Fender in amps that use 6L6 tubes and are amps that DO NOT come from their custom shop. These are used in the Hot Rod series, Blues DeVille series, Pro Tube series, BF reissue series.The GT 6L6GE is used in the 57 Tweed, Vibroverb and Vibro King amps.If you are trying to match your stock tube rating with the GT rating:On Fender amps, output tubes in newer amps are color coded. The scale is:Blue = GT 1-3 rating White = GT 4-7 rating Red = GT 8-10 rating  (less)

application for a 12AU7 tube is as the phase inverter that drives the power tubes. These are very well matched, and so are highly recommended for Ampeg SVT's and other amps using this tube as a phase inverter. Also commonly used as phase inverters in McIntosh Hi-Fi amps, some Ampeg amps, and will yield the most clean headroom in many amps. In the latest Fender Pro Series amps such as the Pro Reverb, Concert, and Twin, this tube in V2 (or a 12AY7), will drop the gain of the gain channel where some feel the tone is of a less intense or "buzzy" character. This will then allow a much wider range in the sweep of the volume and gain controls of this channel.  (less)