Audio Research, next upgrade?

I have been upgrading recently and have had great fun and results. I really like the Audio Research line and I am slowly working my way to the Reference products. I would like to hear what everyone would suggest as the next piece to upgrade, ie CD, Pre, or Amp first. My current system is:
B&W 801
The system sounds great as -is, but always looking for the next improvement.
Thank you
Assuming that your amp and speakers are a good match (I have no idea), then I would suggest getting the best pre-amp you can swing.
It looks like a nicely balanced system. Enjoy it. If you feel like spending money, I'd suggest trying a vinyl setup.
Seems pretty hard to really improve significantly over what you already have, other than what Swampwalker mentions, which is if the B&W is really an ideal speaker load for a 100 watt tube amp - possibly not, but not sure about that. Other than that, I can think of a lot of people that would be pretty darn happy with you ARC array.
Just a thought. Your CDP is a bit dated. I suggest trying to pick up either a CD-5 or Ref CD-8. The rest of your gear is pretty balanced. In truth, there's no end to upgrade fever.
One other thought. If ARC still upgrades the VT100 MkII to the MkIII, you may want to price it out and consider doing it. Give Cal at ARC a call. He always has good advice to share. BTW, another upgrade is changing out your 6550C tubes to the new KT 120s. You'll be pleasantly surprised by the overall improvement.
There are a few Ref5's showing up from time to time here on Gon. Your LS26 will still bring a good price. That might be a good change.
Actually the B&W (801f ) sounds great with this amp. A lot of people on here say that you must have a very large amp to drive these speakers, and they will indeed take a lot of power, even though they are rather inefficient (85db) they are an 8 ohm load. They will easily get louder than I care to listen at. But I prefer to listen at low volumes late at night. And yes I am very happy with my system, but you know how the upgrade fever goes, so I was soliciting opinions as to which piece would make the most notable improvement: source, pre-amp, amp, etc
Change up the preamp line.
Another vote for preamp. Second choice--your source.
If you want a change, the most significant change (for better or worse) would be to change your speakers. I think changes in your Source>pre>amp will be relatively minor compared with a speaker change.

I honest don't know which of the electronics I would change first for the biggest bang for the buck - I suspect the CD or preamp would be the most noticeable change. I owned the CD3 MKII and thought it was wonderful, I really don't know how it compare to this year's models, but it might have held up very well indeed. I would bring the CD to a dealer and compare it with the latest, if you notice a significant improvement - starting at the source proabably has the most implications throughout the chain. If the improvement you hear is marginal or sideways, perhaps a move to the LS27.
I found the upgrade from the ARC CD3 MKll to the ARC CD5 very worthwhile. Not familiar with your other gear.
I would actually keep the CD3 and get a decent DAC (better than the DAC in the CD3). I bet the CD3 is great as a transport and if any upgrade is needed, it would be the DAC. Also, a REF 3 or REF 5 would be a definite upgrade. But, listen to a REF 3 and REF 5 in your home if possible with direct comparison with your LS26 first.

Update the fuse in the CD3 MkII (I suggest a Furutech-make sure you install it correctly). This is a low cost change the works.

Second, update the power cord inthe CD3 MkII to a Shunyata Black Mamba CX version.

Third, update the fuse in the VT100 MKII, then try updating the power cord, use a shunyata CX Black Mamba here too.

Fourth, if you have a little more money, I would update the amplifier to a ref 110 or ref 150 or the CD player to a DAC8 and use my computer to playback WAV files.
Get a vinyl setup if you have the space and the desire. It's going to make a bigger impact on sound than any digital or amplification element you could possibly buy.
Bigger amp. More power and the speakers will sound even better.
Not if he got rid of that dog and had a ls27 instead.
It would surprise all of you.
Of course vinyl always rules, but he may not be into it...yet..:)
I cannot disagree with vinyl.
Get the ARC PH-8 with the latest 6550, a good turntable and cartridge, then start shopping garage sales and thrift stores for the vinyl. For the cartridge, I'd recommend the Audio Tecnica OC9 MKIII. This cartridge is very quiet, great on old mono records too. Once you have this in your system, you'll want to sell your CD-3. A great source for the cartridge is Good luck.
I don't think upgrading to the MKIII version is going to buy you anything. You may want to consider a VS115. It uses the KT-120 as well as 6H30's. You would get greater dynamic range, and speed. I don't think you would loose much if anything in the way of bottom end slam either. See if you can borrow one to try. You may be very surprised.
I had an LS 26, and compared to what it replaced (a bottom of the line VTL tube pre), the low bass was anemic. You have good bass in your speakers and amp, so if you like low end extension and weight, replace the preamp. I went SS to match my amp, and the difference was immediate. I miss the sweetness of tubes, though, so want to find a tube preamp that can go low. LS 27, 5 SE, or?
I am very biased first of all so take all of this with a grain of salt. I am also the maker of the VERITAS Monoblocks.
1. Keep the pre.
2. For you 87db 801, switch out to VERITAS monoblocks - based on other users with 802, MBL's etc. I have compared the VTM 200 to the VERITAS in many systems, is the VERITAS make a large difference. It has not been compared with the VTM 100, on 801 do this is an assumption that it would be better since it was done with VTM200 monoblocks and 802's.
3. Move to Computer Audio with a good DAC - Phasure is excellent however a good DAC with 24/192 will let you hear the emotion in the music. The CD player is good, however once you hear excellent recordings without the missing bits/jitter and other CD associated issues, you will understand.

Good luck!