Compared AU7-S series to NOS Telefunken AU7s, PSVANE T-IIs, Shuguang T series, Shuguang TG black carbon series, Mullard Blackburn 12AU7s, RCA black Plate 5814s..
Compared to original 'VANE T-II series, the new Art series has the top end brightness tamed down, still plenty of detail, much more organic midrange, similar bass performance. Very good imaging. Would fit the ART series in between the T-II series and the Shuguang TG series on brightness and midrange qualities. For some, the T-II VANEs were very revealing, but may have been a touch on the lean side. The new ART series is more open sounding than Shuguang T series or TG series, with similar midrange qualities of these two Shuguang tubes. Tried the AU7 brands in two different preamps, with similar results. Would have to say PSVANE has done their homework on materials used in the plate and cathode construction. The new ART series seems to be a well balanced valve all the way around. Ordering several more sets this afternoon.