New Matched Quad (4) Tung-Sol 6550 Coke Bottle Reissue Vacuum Tubes

New Plate Current Matched Quad of Tung-Sol 6550 (KT88) Coke Bottle Reissue Vacuum Tubes

This 6550 has everything its vintage counterpart featured down to the bottle shape and size, three getter construction, gold grids, and carbonized plates. From the construction down to its sound, the new production Tung-Sol 6550 is everything you would want out of the vintage tube at an affordable price.

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.