The JJ 6SL7 is double triode with an octal socket. The sound is warm and musical without overemphesizing mids and low end. Tightness and focus are this tube's strengths. The bass is never flabby, mids are in place without getting overly prominent and the treble is sparkly yet never harsh. The all new JJ 6SL7 is a great option to bring that JJ tone you know and love to any amplifier that uses the 6SL7 tube type.