Audio Research Preamp Experts?

I have a SP16 and find in to be a great match with my speakers and other components. I think you need to define what it is that you are looking to combine with your system. What is your goal?

"clarity, lower noise and greater dynamics of today's line stages'

Clarity, low or no noise, and excellent dynamics accurately describes my sp16.

Not an ARC guru but I would be surprised if older models had all these attributes to the same extent. It is a very modern sound that is difficult to distinguish as involving tubes to my ears.

The LS5 is the best I have owned. I could never get into the REF series (not rich enough), plus I could never figure out why such a big box is so empty?
The LS5 is XLR only (no RCAs) so that may be a stopper for some.

I don't really like the newer pres with the digial display and no more aircraft toggle switches- I thought that was an ARC staple!! (they do sound great thought)

As for the LS2B, I have always saw it as the overprice sibling to the LS3 because it cost about a grand more and gave you one whole tube!!-wow. I did not think it sounded that much better.

The LS3 played through the "direct" input is about as nutural as things will ever get. No need to go any farther if you don't want extra sound added. You just hear the recording (imho).

I was an ARC dealer for many years and have personally owned almost every preamp/line stage that they have made.

My vintage favorites:

LS5MKIII
LS5MKII
LS2BMKII
SP9MKIII
SP9MKII
SP14
SP11MKII
SP6E

Are you going to buy an Audio Research amplifier? Some ARC preamps work better with certain amplifiers. The earlier tube units like the SP-8 MKII and SP-10 seem to work best with ARC tube amplifiers. I disagree with earlier posts. These older tube preamps have a very clean, neutral and low distortion sound quality when in proper working order with the right tubes and you won't know if it is working properly unless you send it back to ARC and have it checked out.

Next came the hybrids and they seem to work with a variety of amplifiers. I love the sound of an SP-11 MKII with a Levinson 23.5 amplifier. The SP-11 MKII also works well with ARC Classic Series amplifiers.

My favorite ARC preamps include:

SP-8 MKII
SP-10
SP-9 MKII & MKIII
SP-14
SP-11 MKII

If you don't leave these hybrid preamps on 24/7 you will never know what they have to offer because they change dramatically by day three. You won't think its the same preamp.