The Groove Tubes GT-12AT7 is great for most US made amps, especially Fender. Also great for Marshall in the driver stage for a cleaner, brighter tone. These tubes are used in the first, low-level stages of tube amps.
Groove Tubes GT-12AT7 (code 55033)
Guitar Amplifier Tube, Free of Excess Noise and Microphonic Ring
£17.60 (inc vat)