Hello,
I have tried 4 different NOS tubes in mine (ranging in price from $25 to $100 per tube). When all is said and done, I like the stock tube better than any of the NOS tubes! The designer voiced the DAC very carefully in my opinion, every NOS tube I tried sounded a bit dull in comparison.
All of that being said, as far as tube dealers go, in my mind Upscale Audio is the place to buy tubes, if you really want the best. They burn them in for 3 days prior to measuring / matching. First class operation.
I have tried 4 different NOS tubes in mine (ranging in price from $25 to $100 per tube). When all is said and done, I like the stock tube better than any of the NOS tubes! The designer voiced the DAC very carefully in my opinion, every NOS tube I tried sounded a bit dull in comparison.
All of that being said, as far as tube dealers go, in my mind Upscale Audio is the place to buy tubes, if you really want the best. They burn them in for 3 days prior to measuring / matching. First class operation.