Looking for a better tone with more warmth and definition? This is our Standard Retube Kit for the Blackstar Artist 15 and Artist 30 Amps. It contains two ECC83S's along with a Matched Pair of our special Double Mica JJ 6L6GC's for the power section but you can configure this kit to use the JJ 5881's for a reduction in power by clicking on the "Customize" button.