Looking to warm up your Mercury? This is our Standard Retube Kit for the Carr Mercury. It uses two ECC83S's and an ECC81 for the front end and the default power tube is a single JJ E34L. However you can configure this kit to use a JJ EL34II, EL34, KT77, 6CA7, 6L6GC, 5881, KT66, 6550 or KT88 by clicking on the "Customize" button!