Linn vs Audio Research

Marc, I've owned much of the gear you are considering. I've been able to listen extensively to the others, except the Apertura speakers. The options you mention would really be moving in different directions. If you, like myself, are a fan of Linn's ability to resolve inner detail and preserve the PRaT (pace, rhythm and timing) of music, you should stay with Linn. Audio Research gear is good, but has a different character and flavor. Although ARC components are some of the least "tubey" tubed electronics, you will still find that they add warmth to the midrange, roll off the treble somewhat and smear the bass timing/control in comparison to the Linn gear.

My advice would be to stay with Linn. Go with Aktiv Espeks powered by three 2250s. If you haven't already, consider upgrading to the Linn Silver interconnects. They make a nice addition to an all Linn system. Post your system sometime to let us know how it turns out!

Wow! You're talking about a totally different sound and presentation. If you're basically happy with your present system, I'd do the Linn upgrade. A friend of mine has a complete Linn system except the speakers which are Nautilus 802's and it sounds good, he replaced a Threshold 400 with a pair of Klout amps and his system improved, warmer, better bass and less glare through the treble. I'm more interested in the harmonics and soundstaging than the PRaT that Linn is promoting so I prefer my Audio Research tube preamp and VAC amp driving my Nautilus 802's. Our two systems don't sound anything alike even though we use the same speakers and partial cd players, his is a Karik and mine is the Karik/Numeric combo. To me, my system sounds better and for him, he thinks his sounds better, so I hope this helps you out. My music preferences are 60's jazz and 70's rock and my Linn buddy prefers 80's-90's pop and some "world" type music.

Thank you for your answers,
I listened today a totally different system composed with a EAR 534 + 834 pre & amp and BW 805 signature speakers.
I found that voices (opera) and violin had a great texture, full of harmonics. The sound was neutral, with strong but not-firm bass.
These are perhaps the characteristics of tubes.
I find also that my system has some other qualities that I can now perhaps qualify with PRaT (that improves again with espek & 2250 !).
If Audio Research gives the quality of EAR harmonics with the minimum PRaT I have in mine, I am interested !
I plan a direct comparison in January between the two configurations. I will post the results.
Marc

I have a similar system with b&w N802s http://forum.audiogon.com/cgi-bin/fr.pl?vhome&1017001258
I would add a 2250 than consider speakers choices. AR is nice but it a different sound what led you to linn in the first place? That would be the question and how you want your system to sound different than it already does.