[Arran]

Speaking of the 6X5 controversy, I think it's much ado about nothing, at least when it comes to Philcos. Early 40s Philcos that use them are not really prone to power transformer failures, many used the old style equivalent of a 6X5, an #84. The reason brand Z had problems with them is because they used them outside of spec, they did silly things like tried to use two 6X5Gs in parallel in 10 tube sets, with 6V6s in push pull, just so they could use a transformer without a rectifier tube winding. A 6X5 is rated for a maximum of 70 ma, a 5Y3/5Y4/80 is rated for 120 ma, most of these Philcos used either #41s or 6K6s, and only ran them at 193 volts on the B+.
Regards
Arran