New Matched Quad (4) Electro-Harmonix 6550 Ceramic Vacuum Tubes

New Plate Current Matched Quad of Electro-Harmonix 6550 Ceramic Vacuum Tubes

The 6550EH is one of the finest new production tubes for any amp using 6550 or KT88. The 6550EH offers the maximum power of any 6550 with the linearity 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 Genalex 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 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 harshest environment of high powered bass amps like the Ampeg SVT, and combos where the tube is only inches from the speaker and can still deliver great tone.

Will work in place of: 6550, KT88, 6550A

Testing and/or Matching

At VIVA TUBES, all of our customers get the same high standard of testing and matching. Some sellers charge more for premium matches but we believe all of our customers should get the same level of quality and service. 

Tubes are tested and/or matched at full operating voltage with regulated power supply on a Maxi Matcher tester for general mutual transconductance (Gm). In addition, power tubes are tested/matched by plate current (Ip) and preamp tubes are tested/matched by gain. Rectifier tubes will be tested for emissions on a calibrated military grade tube tester. 

Our goal is to match within 5% with an upper limit of 15% (15% is the industry limit to consider a set).

Hand written test data included.

Note that we do offer a few models which are tested & matched at the factory. They will be matched by the same parameters (Ip & Gm) but to the manufacturer's standards. Factory testing will be indicated in the item title and description. 

Guarantee

We offer a minimum 90 day guarantee covering functional defects - including noise unless otherwise stated. The guarantee period begins the day you receive your order.