Well it sounds very nice with a 6K6 in it.. Bloody great in fact!! Everything works well and it’s quiet to boot. The boost switch is most useful!

Then it becomes complicated….

With a 6V6 a faint high pitched squeal is apparent from 0 on the volume dial to 9 oclock, then it works perfect till 4 oclock then squeal comes back (so it’s basically both ends of the dial). Diming the treble or using boost makes it worse.

Furthermore this is with a Weber sig12 speaker. With a Celestion Blue it’s worse with more of the dial affected but with a gorilla (Eminence or similar oem?) 30w I have for testing it’s virtually OK. (All 8ohm..)

With a 6L6 It was pretty bad all over the dials and it came back out again rapidly.

I am not sure I have the OT primarys the correct way, could this be the cause or does my impedance need adjusting somehow?

I’ve read about reversing OT secondarys too but why would it function perfectly with a 6K6? That was referring more to a constant whine anyway.

Having said this I am really happy with the NOS 6K6 tone and the volume level is exactly what I hoped for.. Have got my deluxe for more! Still the option for a few more watts would be handy.

Edit. Should I mention that the atoms were 40/16/16 instead of 40/16/8?