- May 7, 2016
More updates from Elekit.
The limit is a combination of the output capacity of the transformer and the rectifier in the pre tube heater circuit. They suggested using a rectifier with approximately 2x capacity of the expected current draw for the heaters. I ordered a 1000v/2A rectifier to drop in but if that runs too hot I will go up to a 3A, which will require a bit more work to fit as the package size is completely different. As long as the rectifier is upgraded, it should be fine to run the 12BH7 with lower-draw power tubes to keep the total load on the 6v secondary < 4A.
I've also reached out for a couple of quotes on a custom transformer to replace the one that came with the kit, with the 6v secondary winding supporting 4.5A.
Have you ever figured out a replacement transformer to drive more current to both the signal and power heaters at the same time?