what ARC combo- Ref 1/Ref 110 or Ref 3/VT 100 MK3?

Ref 3/Ref 110.

What type of sound are you after?
Colored or neutral?

If you want neutrality then the REF3/VT is the way to go.

In my opinion, REF1 will totally defeat the purpose of REF110.

I'd rather go for the LS-25MkII/REF110 combo. Or REF2MkII/REF110 if you can do that. REF1 is a "sweet" sounding preamp with huge soundstage and a lot of bass, but it is pretty colored with heavy, slow bottom. Not the best if you're thinking about getting a neutral preamp that will let your source shine through. In my mind, REF1 is not the ARC's best preamp. Not very close to reality in its timbral shades. I would go as far as saying that I would get the LS-25 or LS-25MkII instead. Don't get me wrong, if you like colored sound, with lots of mids and slow and heavy bottom(if your system lacks these abilities this may be the way to fix it), go for REF1. Otherwise, steer clear.
JMO.

i'll go for a "better" preamp. so Ref3/VT100 mk3.

just my guess.

You may also consider the LS26 Ref 110 combo.The 26 is really close in performance to the Ref 3 and the 110 is much better than VT100mkIII.That's my opinion anyway.

I second what audphile states (had ls15, ls25Mk I and II, and Ref1, and a VT 100mkII) and given above pairings, as Kschiu says, the Ref3 -> VT100MKIII would sound superb into the same speakers (assume either speaker can be drive effectively by ~100 watts push/pull 6550 quads), and better overall sound than REF1 -> Ref 110, just mho.

...Dave Mitchell this is one for you!

thanks for all the comments so far- looks like the preference is to put more $$ into the preamp than the amp

Get the Ref3 no matter what....you can always upgrade the amp. The Ref3 is a monster.

IMO LS-26/Ref 110 is the way to go. The LS26 is close enough in performance to Ref 3 to consider it as an option on a limited budget. I'm Ref 3/Ref 110 owner.

If you are building a system then I'd say get the better, more neutral pre-amp first. Ref3 is ok..

I was able to sound test the ARC LS26/REF 110 combo. It was vey good. In the end, however, I thought the REF 3 with my solid state amp offered the most bag for the buck for the cost. The REF 3 is so good. It really makes a huge difference in a system more so than the amp in my opinion. Depth, soundstage, etc.. all those terms we know of. I have since upgrade my amp to the REF 110. I am very happy with it.

Thanks everyone- sounds like the preamp upgrade is the winner, and Ref 3 in particular a solid bet.