Hey Danny, no they don't have to be the same or matched etc as they are providing progressive gain stages. IIRC MJMP said the V3 tube uses one of its 2 triodes as a cathode follower thus you get 5 gain stages across the 3 tubes (each tube has 2 triodes). Personally I'm a fan of the new sensor Mullard long plate re-issues, nice 3D tubes, plenty of very smooth gain, nice low end (though I don't have a 3TM, they are great in my MP2s). There's also a short plate Mullard re-issue, MikeB used a short plate in V1 of his MP1, worked well for him. So you can mix and match, typically you'd go for the long plate after a short plate if you are mixing them up. Boogie SPAX7s are also good tubes (they are re-badged as there are only 3 or 4 tube manufactures and they are often JJs (which you don't like) but not always). The Mullards are Russian tubes (Reflector factory). They also make a bunch of other re-issues like Tung-sol and Sovtek. Svetlana are also well regarded Russian tubes. I posted some comparison pages in previous posts (ages ago) in this topic.