JJ KT88 is an amazing tube! They are extremely thick and rich sounding with no
loss of high end like the chinese made KT88’s. Most amps using 6550’s can also
use the JJ KT88’s for a different sound. You want THUNDER from your vintage
Ampeg SVT? Then this is your tube. For you guys with 800 series Marshall's and mid
to late 70's Mark II series Marshall's using 6550’s, these are a drop in
replacement, just re-bias and play! Unlike some of the New Censor made tubes, none
of the pins are connected to the metal bases so there are no possibilities of
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.