I got a Tung Sol kit from audiotubes via Amazon. It's specifically for the Epiphone BC30. Changing the tubes was not too difficult, wore latex gloves and rubber sole shoes, didn't touch anything but the tube covers and rings to remove screws and pull out Chinese original tubes one at a time, replace with Tung Sol ones and reassemble the retainer rings and covers. The reverb tube (first ax7 on right with the amp upside down) gets the balanced pin one. Rest was a snap to install. The amp sounds smooth and responsive, with no hum. The tone is much better than the original chinese tube based tone. Less harsh, more clarity and even response when using independent eq. Very happy with the result as after ten years, one of the original tubes had blown and I was not willing to trash this beautiful amp.