Mixed driver tube for Mcintosh MC275


I just wonder if anybody know which sections of Mcintosh MC275's driver tube are most crucial? Is it all sections of equipment are the same in terms of the importance of the driver tubes. Another thing, is it using a tube that has a sonic trait that is different than another like combining a thinner more detailed tube like a Telefunken can actually work very well with a warmer tube like a Mullard?
yewhlock
Maybe I will try the RCA's in the phono section. The tellies are quite good and very neutral.
In simple audio language, the more expensive tube is usually the better tube. If you have a Ferrari, use the best tires you can afford. Same for a McIntosh MC-275... 
Hi, I have a similar question.  I have a pair of Telefunken 12AT7 and a pair of Mullard 12AT7, where should I put them?  In the first response, it seems to suggest V3,V4 should match and V6,V7 should match.  However, from other places, I read that V3, V6 are output drivers, one for each channel.  V4, V7 are cathode followers, one for each channel.

In order to balance left and right channel, does that mean, I should put one matched pair In same brand in V3, V6; another matched pair in same brand in V4, V7?