From New Sensor:
“KT88 Mullard is an exact copy of the KT88 valves that were manufactured by Marconi-Osram for Marshall in the late 1960s and 1970s. Excellent replacement output valve for the Marshall Major to retain the original sound.”
Visually and sonically, this tube is a near-twin to the Genalex KT88. In side-by-side listening, the Mullard offers a signature that is practically identical, though it leans slightly into a warmer mid-range and a noticeably stronger bass response. While the plate material appears marginally different, the most significant physical distinction lies in the grid rods. Unlike the Genalex, which utilizes copper rods for superior thermal conductivity, the Mullard uses standard metal or aluminum. While copper is roughly twice as effective at dissipating heat through the grid fins, the Mullard remains a robust and reliable performer.
While New Sensor claims this is an “exact copy” of the original British valves, that statement is historically and technically inaccurate. The original Marconi-Osram (MOV) KT88s were manufactured using specific metallurgy and vacuum pumping techniques that no longer exist in modern Russian production. The internal geometry and materials—specifically the lack of copper grid rods in the Mullard—mean it cannot physically replicate the thermal stability or the exact “bloom” of a true vintage British KT88. While it is a high-quality modern tube, it is a reproduction in spirit and name rather than a carbon copy of the original UK engineering.
Final Verdict: If you want the Genalex sound at a more accessible price point, the Mullard KT88 is a fantastic, high-value alternative, provided you understand it is a modern tribute rather than a true vintage replacement.
From New Sensor:
“KT88 Mullard is an exact copy of the KT88 valves that were manufactured by Marconi-Osram for Marshall in the late 1960s and 1970s. Excellent replacement output valve for the Marshall Major to retain the original sound.”
Visually and sonically, this tube is a near-twin to the Genalex KT88. In side-by-side listening, the Mullard offers a signature that is practically identical, though it leans slightly into a warmer mid-range and a noticeably stronger bass response. While the plate material appears marginally different, the most significant physical distinction lies in the grid rods. Unlike the Genalex, which utilizes copper rods for superior thermal conductivity, the Mullard uses standard metal or aluminum. While copper is roughly twice as effective at dissipating heat through the grid fins, the Mullard remains a robust and reliable performer.
While New Sensor claims this is an “exact copy” of the original British valves, that statement is historically and technically inaccurate. The original Marconi-Osram (MOV) KT88s were manufactured using specific metallurgy and vacuum pumping techniques that no longer exist in modern Russian production. The internal geometry and materials—specifically the lack of copper grid rods in the Mullard—mean it cannot physically replicate the thermal stability or the exact “bloom” of a true vintage British KT88. While it is a high-quality modern tube, it is a reproduction in spirit and name rather than a carbon copy of the original UK engineering.
Final Verdict: If you want the Genalex sound at a more accessible price point, the Mullard KT88 is a fantastic, high-value alternative, provided you understand it is a modern tribute rather than a true vintage replacement.