The 4K primary (sometimes 3.5K or 3.8K) is suitable for a pair of EL34s. 6L6 variants perform best with a higher impedance primary, typically 6.6K.Bieworm wrote: ↑Fri 04/02/21 1:11 amis that so? If I look for output transformers there is always the tube type specified in the datasheets. It always says both 6L6 an EL34.TriodeLuvr wrote: ↑Thu 04/01/21 10:10 pm6L6 and EL34 need output transformers with different primaries. It's not really possible to compare the two types unless the transformers are changed with them.
Jack
I have a 36W OT with 4k prim...
The chart below is from the 6L6WGB datasheet. The loss in output power when the two tubes drive a lower Z transformer is typical of all the 6L6 series. Whose datasheets are you reading that don't make this distinction?