OK Guys:
Sorry this has taken so long but summer vacation and then a pretty thorough testing process has left me with these conclusions:
I did a direct comparison of the following 5AR4's: My vintage Mullard (Blackburn), Create/Synergy and the stock Sovtek that came with my LS100. I swapped each tube in and listened to the same set of recordings (four titles of different genres)over a two day period.
First, are differences between the three tubes are apparent but they are slight. I found a more significant change (to the positive) swapping the stock 6SN7's with the Sophia Electrics. Not sure if this is a function of the degree to which the rectifier tube can impact the sound or simply that the sonic difference between these rectifier tubes is less significant.
Having said that, I did feel that the Mullard and the Create tube outperformed the Sovtek in my system--the latter sounding a bit lifeless by comparison. In my system, the differences between the Mullard and the Create are quite interesting. The Mullard has a vintage warmth and glow but is less resolving. The Create does a better job differentiating between musical lines and instruments in the mix. It is a very clear, clean tube but does not have any edge or glare. My system leans a tad toward the warm side and the LS100 has a distinct touch of tube sound. In my setup I prefer the Create tube. It brings a measure of realism, insight and detail to the music that the Mullard cannot touch. Whether the Create would sound superior in a system that leans toward the cool and analytical is an open question. It may, under those circumstances, deprive the music of some body and warmth that is needed to sound real. For my system it is a no-brainer so the Create it is. If anyone wants my Mullard just shoot me an email and we can work out a price.
