I’ve been a DIY fan for a couple of years. I started out by building a Billie form a kit. Then I used the supplied schematic to modify the amp from the original 6sn7 driver to a 6s45pi. My initial impression was that it was an improvent over the mu stage 6sn7. Recently I constructed a 6l6 PP. It uses separate PS (5aR4/choke 320v. 300ma). I was surprised to find the the PP was in most respects superior to the 300b SE. I began to wonder if the 6s45 was not the most musical of drivers. I’ve heard that some people drive their 300bs with 2a3s, but looking at the data there doesn’t seem to be enough gain to do this. That’s when I thought of K&K. Could I use a transformer to get the gain I need? I’ve got a separate power supply. 2a3 are not too expensive. I would have to buy a 2.5v filament supply and a step-up transformer. What do you recommend?