The 12B4A converter allows the Kenzie and Kenize Encore to use the 9 pin 12B4A tube without further modifications. As stocks of 1626 tubes become increasingly rare and prices rise, finding alternatives to use becomes more critical. Additionally, tube rolling is a way of personalizing the sound of your system. The 12B4A tube betters the noise floor of the 1626 tube and nearly doubles the output of the Kenzie and Encore. If you have more demanding orthodynamic or planar headphones but love the sound of your Kenzie, the 12B4A might be the right choice. Instead of searching for the correct adapters and waiting for them to come in and then searching for the right tube variant. We have taken the guesswork out of tube rolling. Our combination of adapter and matched tubes have eased the guesswork in rolling. Plug them in and enjoy the benefits without the work.