Electro-Harmonix 6550 Matched Power Tubes
The Electro-Harmonix 6550EH power tube is the finest current production tube for any amp using 6550 or KT88 valves. The 6550EH offers the maximum power of any 6550 with the linearity that guitar and bass players want. With 42 watts of plate dissipation in tetrode operation and 44 watts in triode, the 6550EH offers an improvement in power over even the most desirable vintage types including the Tung-Sol 6550 and Genelex KT88. This extra headroom in a 6550EH equipped amp means bass players can finally realize the full dynamic range of the instrument and the sweetest tone available.

The extra ruggedness of the 6550EH power tube was engineered with the punishing abuse of guitar amps in mind. The nickel steel side rod mica supports ensure that the 6550EH will hold up in even the most punishing environment of high powered bass amps like the Ampeg SVT and combos where the tube is only inches from the speaker and still deliver the sweetest tone of any 6550 or KT88. The 6550EH will greatly improve the performance of any amp using 6550's.