Want a very smooth and rich tone with less grit? This is our Gold Pin Option Retube Kit for the Dr. Z Route 66. This kit includes a matched pair of the JJ KT66's for power, a JJ GZ34, one Gold Pin JJ EF806 to replace the EF86 and one balanced Gold Pin ECC83S for the phase inverter. The JJ KT66's DO NOT have any of the pins attached to the metal bases like the sovtek and sovtek-tungsol tubes do so there are no possibilities of shorting with the JJ's.