Brian,
I have the same unit replaced the philips with some 60's Amperex,gold pins-sound superb-warmer overall and rounder bass-I also have a pair of Raytheon 7308's which are better than the Philips but not as good as the Amperex.
Kevin tends only to sell to previous customers especially NOS 6922's.
There's an excellent FAQ/Description of NOS tubes somewhere on the Web,can't remember where now perhaps a search might throw it up-it details the best of NOS tubes.
I'm in the UK,I believe buying NOS tubes here is about the only aspect of hi-fi that's cheaper than the US.
I've messed about with this unit a bit,I think whatever quality NOS tubes you use will be an improvement but I think also you have to be realistic about the improvement it will make considering the cost of the X-10D.
Good luck.
I have the same unit replaced the philips with some 60's Amperex,gold pins-sound superb-warmer overall and rounder bass-I also have a pair of Raytheon 7308's which are better than the Philips but not as good as the Amperex.
Kevin tends only to sell to previous customers especially NOS 6922's.
There's an excellent FAQ/Description of NOS tubes somewhere on the Web,can't remember where now perhaps a search might throw it up-it details the best of NOS tubes.
I'm in the UK,I believe buying NOS tubes here is about the only aspect of hi-fi that's cheaper than the US.
I've messed about with this unit a bit,I think whatever quality NOS tubes you use will be an improvement but I think also you have to be realistic about the improvement it will make considering the cost of the X-10D.
Good luck.