Tube rolling, the practice of swapping stock tubes that we designed the product with for a different variety to change the sound of a preamp or power amplifier is something we not only support but encourage. It's why we made it super easy on the BHK series to roll your own tubes. In the BHK preamp, you can select either 12V tubes of 6 and 7-volt variety with the simple change of a jumper. Here's how to do it.
httpv://youtu.be/vIKGN8hQazI