We happen to be packing a lot of Moreplay kits today and in the process I am testing the latest batch of 6V6 tubes. These are Russian 6N6Cs. I am noting that they test a little bit low on transconductance when I first put them in the tube tester, but come up to spec after about 30 minutes. So I would suggest running the voltage tests on your Moreplay twice - once when you complete the build, and then once more after the preamp has run in for an hour or so. If the plate voltages seem a little off at first they will probably pull into spec after the tubes run for a while and the cathodes form up a little more.
