Studio Pre tubes: tung-sol vs mesa STR

[ytse_jam]

I just got two Tung-Sol 12AX7 tubes and tried one in different positions in my Studio Pre. I recorded these clips for the interested/curious ones and to get some opinions (what are the benefit/worsening of the tung sol in the various positions in your opinion? which clip do you like the most?). Single-tracked and double-tracked content.

Here are the clips (named SP1...SP5):

http://www.soundclick.com/bands/default.cfm?bandID=642176&content=music


Tube configuration as follows:

SP1
V1: Mesa STR SPAX-7 (I suppose it is premium grade/low noise 12AX7)
V2: Mesa STR 12AX7-A (I think it is the same as the SPAX-7, maybe old product code?)
V3: Mesa STR SPAX-7
V4: Mesa STR 12AX7-A
V5: EH 12AT7

SP2
V1: Tung Sol 12AX7
V2: Mesa STR 12AX7-A
V3: Mesa STR SPAX-7
V4: Mesa STR 12AX7-A
V5: EH 12AT7

SP3
V1: Mesa STR SPAX-7
V2: Tung Sol 12AX7
V3: Mesa STR SPAX-7
V4: Mesa STR 12AX7-A
V5: EH 12AT7

SP4
V1: Mesa STR SPAX-7
V2: Mesa STR 12AX7-A
V3: Tung Sol 12AX7
V4: Mesa STR 12AX7-A
V5: EH 12AT7

SP5
V1: Mesa STR SPAX-7
V2: Mesa STR 12AX7-A
V3: TMesa STR SPAX-7
V4: Tung Sol 12AX7
V5: EH 12AT7