I can understand the Less-is-more approach, but, that could mean trying to do more with less options and leeway. One tube would mean less gain (generally not a problem), but it would also mean very high output impedance (no cathode follower). Also, simplicity could limit the choice of tube; for example, one may have to use the 6h30 because of its high transconductance and low output impedance for such a "simple" circuit. Some people like the sound of this tube, others, as noted above, don't.
Every design choice means some kind of tradeoff. Conrad Johnson, avoids a cathode follower by having many tubes in parallel. It is still a simple circuit, but, it does mean many tubes.
I have a linestage (Emotive Audio Epifania), whose topology I have no understanding, which uses one tube (twin section tube) per channel, supposedly with no cathode follower needed to lower impedance. I suppose this qualifies as few tubes "in the signal path," but it has a LOT of tubes in the power supply. It uses tube rectification and six gas regulator tubes. The designer himself thinks that the power supply is "in the signal path," hence the great care in getting good power.
Mjcmt, if you like the tubes you have, then, just sit back and enjoy the sound. But, if you would like to chase something else, you do have the opportunity to radically change the sound of those amps just by changing tubes. To some, that is part of the fun, to others, that is what is frustrating (some people may like the sound they are getting but hate the idea that "better" may be lurking out there somewhere). If you want to look at alternatives, just be aware that, particularly with 6SN7s, results are NOT necessarily related to price or reputation; it depends on your taste, system and synergy with your other equipment. This can get very expensive and the results can be erratic. In my system, very expensive Tungsol roundplates are the best, but, very expensive metal-based GE's were very lean and unpleasant.
Every design choice means some kind of tradeoff. Conrad Johnson, avoids a cathode follower by having many tubes in parallel. It is still a simple circuit, but, it does mean many tubes.
I have a linestage (Emotive Audio Epifania), whose topology I have no understanding, which uses one tube (twin section tube) per channel, supposedly with no cathode follower needed to lower impedance. I suppose this qualifies as few tubes "in the signal path," but it has a LOT of tubes in the power supply. It uses tube rectification and six gas regulator tubes. The designer himself thinks that the power supply is "in the signal path," hence the great care in getting good power.
Mjcmt, if you like the tubes you have, then, just sit back and enjoy the sound. But, if you would like to chase something else, you do have the opportunity to radically change the sound of those amps just by changing tubes. To some, that is part of the fun, to others, that is what is frustrating (some people may like the sound they are getting but hate the idea that "better" may be lurking out there somewhere). If you want to look at alternatives, just be aware that, particularly with 6SN7s, results are NOT necessarily related to price or reputation; it depends on your taste, system and synergy with your other equipment. This can get very expensive and the results can be erratic. In my system, very expensive Tungsol roundplates are the best, but, very expensive metal-based GE's were very lean and unpleasant.