Newbee, an idea for you. I have a Ray 128 myself and had been curious about the use of 6N1P tubes in it after reading positive stuff about this Russian tube, which is not exactly a 6922/6DJ8 replacement, but close. I queried Raysonic and got a green light for the substitution. I don't know whether this applies to the 168 or not (didn't ask). A quartet of the 6N1P's from a Ukrainian seller on Ebay cost all of $17.00 including shipping from the Ukraine! I know, sounds weird, but they got to Potomac, MD in less than 10 days. They're in the 128 to stay. I was earlier using Mullards and (my favorites in this CDP) JAN Phillips 6922s. Dave