[MQ Matching Set of 4]

JJ vacuum tubing is produced by JJ Electronic, Slovakia under the former TESLA production facilities.
JJ Electronics has put effort to pre pipes, such as recreating TELEFUNKENs ECC803 and ECC802, and the high quality of the pre tube.
The JJ vacuum tubing can be purchased here, has been given a 13 digit serial number after adequately aging in domestic automatic sorting machines, and it has been given a high precision characteristic measurement. (The serial number is attached to the box) Measured and matched and shipped. The error of a pair measured by JJ Electronics is often reduced by dozens of percent even after testing in the same measurement conditions. However, in this high-precision selection, the error of the pair can be reduced to 5% (within 10% of pre tubes, depending on the measurement conditions).
Other than the electrical characteristics of the product (damage to other devices, bulb tilt, valve height, logo missing, etc.) are not covered under the warranty.