I have an older Super PAS 3si preamp which replaced a CJ PV5, and Audio Research LS9 preamp. It came with NOS Phillips 12AX7's and I have tried several others since and
it holds it's own. It does not have the last word in transparency but the latest versions with a different tube are said to be pretty good and much more transparent. I have been trying to buy one of the power amps for a while but they have all been out of my reach when they pop up. I have couple friends that have one of his amps and they say it's one of the best they have heard. Regardless his enginering is solid and execution is top notch. He doesn't skimp on power supply quality like some companies who would charge you 4 or 5 times the money and the power supply is substandard in comparison to many other offerings.
it holds it's own. It does not have the last word in transparency but the latest versions with a different tube are said to be pretty good and much more transparent. I have been trying to buy one of the power amps for a while but they have all been out of my reach when they pop up. I have couple friends that have one of his amps and they say it's one of the best they have heard. Regardless his enginering is solid and execution is top notch. He doesn't skimp on power supply quality like some companies who would charge you 4 or 5 times the money and the power supply is substandard in comparison to many other offerings.