The JJ EL34's are very sweet and have that old European EL34 tone with extremely detailed mids and they transition smoothly when over driven. Often overshadowed by it's big brother the JJ E34L, these tubes are excellent anywhere a softer, smoother and more classic EL34 character is desired. This tube is as close to an NOS Mullard as you can get in a new production EL34 tube. If you want a more modern tone that is very tight and punchy then look to the JJ E34L.
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.