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.
Groove Tubes GT-12AU7 (code 55034)
Guitar Amplifier Tube, Clean Headroom in Most Amps, can be used as Phase Inverter
£23.99 (inc vat)