Too me, the more expensive tube preamps, assuming they are of good quality, is the ability to play louder with less conjestion and/or decreased dynamics. As stated above, I think this has to do with the power supplies more than anything else.
The AI M3A preamp is awfully good for the money it goes for used. It still stands comparison to some of the best available. If you don't need a phono section, then the 2 tube L-1 is nothing but a bargain used. I have owned both of these for long periods. The L-1 has just a small amount of that tube thing going on where the M3A is very neutral for a tube product. Also, either of them change with the use of other brand tubes. You can taylor the sound somewhat.
I curently use an Aesthetix preamp that costs almost twice what the L1/M3a does. Yes, it is just a little cleaner through the mids and has firmer bass but it is in its ability to play louder where it stands out.
I have always used a tubed preamp with a solid state amp. It kinda of gives you the best of both worlds. The only solid state preamps I have heard that I consider decent is Ayre's K5xe and K1xe. Other than those, too many SS colorations imo. I have heard a couple of decent passives.
The AI M3A preamp is awfully good for the money it goes for used. It still stands comparison to some of the best available. If you don't need a phono section, then the 2 tube L-1 is nothing but a bargain used. I have owned both of these for long periods. The L-1 has just a small amount of that tube thing going on where the M3A is very neutral for a tube product. Also, either of them change with the use of other brand tubes. You can taylor the sound somewhat.
I curently use an Aesthetix preamp that costs almost twice what the L1/M3a does. Yes, it is just a little cleaner through the mids and has firmer bass but it is in its ability to play louder where it stands out.
I have always used a tubed preamp with a solid state amp. It kinda of gives you the best of both worlds. The only solid state preamps I have heard that I consider decent is Ayre's K5xe and K1xe. Other than those, too many SS colorations imo. I have heard a couple of decent passives.