Ok the Lyr has arrived and been unboxed, plugged in and switched on.
Good bit - straight out of the box it lights up my HE-500's and plays music through them with a drive I have not heard to date.
Came supplied with a pair of 6BZ7s.
Not so good bit. When first switched on there was a bit of a hum through the L ch. I flipped the switch to high gain and it went straight away. I played 3-4 tracks before leaving it on and going off to make some calls. Came back and pressed play - damn, just sound through the R ch, with a much lower volume through the L ch.
So waiting for unit to cool down so I can swap tubes over and see if the fault swaps channels with the tubes.
Dammit I don't think I have anything else in the house to hand that I can use instead. What a bummer.