New Matched Quad (4) Electro-Harmonix 6CA4 / EZ81 Vacuum Tubes

New Matched Quad of Electro-Harmonix 6CA4 / EZ81 Vacuum Tubes

The most reliable and best sounding small rectifier on the market. The 6CA4, 6CA4A and EZ81 are all the same tubes / compatible. An excellent choice for 18 Watt Marshalls in particular, as well as for hi-fi applications.

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.