Don't know if anyone is still following this old thread but here's my 2 cents.
In the line stage I tried a pair of NOS Bugle Boys as well as Telefunken 12AX7s both of which I liked better than the stock tubes but found it a bit edgy. Then I tried a pair of Mullard CV4004 which were selected for having close matched sections. I was informed that VTL selected the original tubes this way for minimum distortion.
I found the CV4004 to have a nice balance bottom to top with just a touch of warmth that helps smooth out digital recordings without giving up airiness. I also found them to have a great wide and deep sound stage.
I tried another pair of CV4004s in the phono stage but found the combination a bit too lush for my combination. So I finally settled on a pair of NOS Telefunken in the phono stage. I use the MM setting with a high output Blackbird cartridge. The combination really works together in my system. Great high end extension, soundstage, etc. Sound very accurate to me and the Mullards in the line stage have that warmth to keep everything real. The 12AT7s are all original, I believe VTL used NOS Sylvania for those.
As far as noise I've had one tube in the line stage get noisy so I swapped the 2nd pair of Mullards in that I originally had for the phono stage and have had no other problems.
In the line stage I tried a pair of NOS Bugle Boys as well as Telefunken 12AX7s both of which I liked better than the stock tubes but found it a bit edgy. Then I tried a pair of Mullard CV4004 which were selected for having close matched sections. I was informed that VTL selected the original tubes this way for minimum distortion.
I found the CV4004 to have a nice balance bottom to top with just a touch of warmth that helps smooth out digital recordings without giving up airiness. I also found them to have a great wide and deep sound stage.
I tried another pair of CV4004s in the phono stage but found the combination a bit too lush for my combination. So I finally settled on a pair of NOS Telefunken in the phono stage. I use the MM setting with a high output Blackbird cartridge. The combination really works together in my system. Great high end extension, soundstage, etc. Sound very accurate to me and the Mullards in the line stage have that warmth to keep everything real. The 12AT7s are all original, I believe VTL used NOS Sylvania for those.
As far as noise I've had one tube in the line stage get noisy so I swapped the 2nd pair of Mullards in that I originally had for the phono stage and have had no other problems.