@mesch the article @juanmanuelfangioii shared from enjoythemusic makes an interesting comment. I also own some of the absolute best-of-best Blackburn plant Mullard 12au7 cure-tracer close matched triodes from Brent Jesse too, similar to what @dekay may have been referring to above.
Sure, they are nice, expensive. and my other PSVANE 12au7 hold their own against them comparably, and I can run them all of the time with no worries. My amps came stock with JJs, and there are select au7s that sound much better, imo.
Noting this comment in the recent Pharaoh_II article link above, quote:
- "My comparisons of the Pharaoh integrated amps were based on using only stock tubes for evaluation. I did substitute in a couple of rare vintage NOS Mullard 12AU7 tubes in the Pharaoh I. It got me closer to Pharaoh II, but not all the way. The tubes cost $300! The people at Rogue Audio have great ears and they choose tubes to go in the production models very carefully"
When you call Rogue, maybe they can share more about why some of the more recent designs including the Pharaoh_II (reportedly) may sound better. See what they say, and why?