I wanted to let everyone know about my recent experience with some top end 6SN7 tubes, namely the Shuguang CV-181 Treasure and the Tung-Sol 6SN7GT Round Plate. I've spent over a month with these and feel I have gotten comfortable with the sound of each and not judging based on the marketing hype of each. These tubes were being used in a WA5 with Shuguang 300B-Z tubes and EML 5U4G Rectifiers. The source is a PWD, which I consider to very revealing and neutral. Finally the headphones used were HD800s and LCD-2s, both top end headphones that are extremely revealing.
To me both of these tubes are actually very close in performance and in no way would I dismiss the CV-181 tube, even with the cream of the crop TS 6SN7GT. On a headphone like the HD800 which can at times use a little extra oomph on the lower end, the Tung Sols definitely deliver in this department. They are well detailed throughout the spectrum and have a nice lower end extension. On the LCD-2, which tends to be darker of a headphone, the Tung Sols also perform beautifully, but can get every so slightly over-bassy to my liking. The bass is very addicting and amazingly well detailed, but can get a little too noticeable during certain songs with low end acoustic guitars/drums on the LCD-2.
In this department, the CV-181 works very well with the LCD-2 and helps contain the bass a little and extend higher on the upper frequencies. The CV-181 sounds also a little more detailed overall ("crystal clear" would be my way of putting it). On the HD800s though, the Shuguangs can feel a little thin depending on music types you are listening to. I could see classical working better with the CV-181 and more acoustic/jazz/rock sounding better with the Tung Sols.
Anyhow, I've decided to keep both sets of tubes since they are each very appropriate to whatever music genre I might be listening to. One has more warmth, punch, and lower end extension, while the other is more detail oriented and with a more neutral / clean presentation of the sound.
