I have owned the Modulus 3, 3a, L1, L2 and L3 and I can say for the money nothing comes close. The M3a, when it first came out, was the preamp of the ages. Stereophile had it in their "Class A" ranking for a long time and it did sound better than the M3.
As for sound, as is usual for audiophiles, sound is in the ears of the beholder. The AI stuff was always very neutral for a tube pre. Compared to ARC, the ARC had a more "Tubey" sound. ARC's did not have as good bass and more midrange bloom. Compared directly, I always felt the AI a notch above personally and I liked their more neutral presentation. Many like the euphoric tube sound but I personally feel it masks certain aspects of the sonic picture. Easy to listen to though with the warmth, etc. But an accurate portrayal of the music, no, I don't think so. But each has their own thing and the debate of the "Best" is an effort in futility.
My last AI was the L3, which was too me, one of the best sounding preamps I had heard to date. Clean, neutral and very quiet. The price has gone up to $3795 but I still consider it a steal for the money.
As for tube life, as long as you use good quality 6H23's from AI or a place like Upscale Audio, you are fine. These tubes were very durable and stayed quiet. Never an issue with me. Other NOS tubes, hmmm, good luck. They may go a month before they got noisy and I couldn't really say they improved the sound, just different.
As a side note, I have personally felt that the tubes the manufacture installs and were used to fit the design of the preamp sounded and worked best overall. I know this goes against everything audiophile but the circuits were designed for the particular tube. Of course, because of price and availability, manufactures can't design for NOS tubes. With AI, my advise is to stick with original tubes and you will be rewarded by longevity and great sonics.
As for sound, as is usual for audiophiles, sound is in the ears of the beholder. The AI stuff was always very neutral for a tube pre. Compared to ARC, the ARC had a more "Tubey" sound. ARC's did not have as good bass and more midrange bloom. Compared directly, I always felt the AI a notch above personally and I liked their more neutral presentation. Many like the euphoric tube sound but I personally feel it masks certain aspects of the sonic picture. Easy to listen to though with the warmth, etc. But an accurate portrayal of the music, no, I don't think so. But each has their own thing and the debate of the "Best" is an effort in futility.
My last AI was the L3, which was too me, one of the best sounding preamps I had heard to date. Clean, neutral and very quiet. The price has gone up to $3795 but I still consider it a steal for the money.
As for tube life, as long as you use good quality 6H23's from AI or a place like Upscale Audio, you are fine. These tubes were very durable and stayed quiet. Never an issue with me. Other NOS tubes, hmmm, good luck. They may go a month before they got noisy and I couldn't really say they improved the sound, just different.
As a side note, I have personally felt that the tubes the manufacture installs and were used to fit the design of the preamp sounded and worked best overall. I know this goes against everything audiophile but the circuits were designed for the particular tube. Of course, because of price and availability, manufactures can't design for NOS tubes. With AI, my advise is to stick with original tubes and you will be rewarded by longevity and great sonics.