The TAD 7025-S is a faithful reproduction of the legendary original Mullard ECC83 valve which was made in England until the late 1960s. This tube is regarded as the holy grail among the double-triode preamp valves. The extra thick mica spacers support the rugged mechanical construction and the careful TAD quality control proceedure ensures performance stability and low microphonics. The TAD 7025S delivers a rich, harmonically complex tone and mid-range warmth that is just outstanding compared to any other currently manufactured tube today. Great warm and clean tones and creamy overdrive. We recommend this tube for classic British style amps (rather than for modern high-gain amps) as well as for vintage-style open-back combos to achieve a stunning complex tone with silky smooth but rich tone. The TAD 7025 S can replace any ECC83, E83CC, 12AX7, 12AX7A, 12AX7M, 12AX7WA/WB/WC/LPS/EH, 5751 or 7025. Upgrades 12AX7A and ECC83 tubes. Replaces E83CC tubes. tech-tip: especially recommended in second positions or tone stacks in vintage British amps.