OK guys, today I tried the RTC's with the LCD-3 on the Lyr (this is a Lyr thread after all - will try them on the Liquid Glass later). My technical evaluation is . . . "Wow!"
I don't believe the LCD's have ever sounded better on the Lyr:
1. Much smoother, richer presentation than the HD 800 and D2000. All the detail is there in each, but the LCD-3's are more musical, warmer; more natural sounding. These cans really love these tubes. I see why Sceleratus loves them so much with his LCD's - it is a great match.
2. Surprisingly (to me anyway), the soundstage is much bigger with the LCD-3 than with the HD 800. More "air" surrounding the instruments as well. The LCD sounds much more like an actual performance. I play a lot of baroque music in ensembles (on period instruments), and the LCD/RTC combo makes baroque strings, flutes and oboes sound more natural than just about anything else I've listened to lately. Very like an actual performance in a mid-sized venue (like a church).
3. I do notice more high frequencies with the HD 800, but that's not to say the LCD's are rolled off. Rather, there is just a more natural "roundness" and sweetness to the sound. Both presentations are pleasant - the HD 800's are like a delicious ice-cold extra-dry vodka martini, while the LCD's are more like a delicious caramel candy apple. Both good but different (OK enough silly metaphors).
I had about given up using the LCD-3's with the Lyr, but the RTC tubes are going to change that.
Many thanks to Sceleratus for turning us on to these wonderful tubes!