KT77

A beautiful reproduction of the original KT77. This tube is a replacement for all standard EL34 applications. It has an extended frequency response with big/chunky lows (even deeper than the E34L’s) and chimey/present highs. The mids are very smooth for an EL34 type tube, with that dense and harmonically rich overall sound all KT types are known for.

A favorite in Marshall applications and anywhere added harmonic complexity is desired.

For hifi users, the KT77 will provide more emphasis in both the extreme lows and high frequency regions compared to a standard EL34 type. This tends to work great with small format monitor speakers, or anywhere a wider and more open sound is desired. However we tend to prefer the traditional EL34 and E34L in most horn based systems.

The story: The JJ KT77 was built per Bob’s request back in 2005. After having great success with the JJ 6V6S we knew JJ was capable of doing this historic tube justice. In the development process several revisions were made and a pair of Bob’s original Genelex KT77’s were sacrificed (yes it still haunts him…). In 2006 the final variation was finalized and the tube has been in full production since.

After a 24 hour burn in all power tubes are tested for noise and matched at multiple operating points for plate current (± one milliamp) and transconductance. Please leave us a note in the comments section as to what amp they’re going into and or if you’re looking for a specific grade.