ARC LS1, LS2, LS3 , or LS7, which to buy?

Oh great and knowing Audio Research mavens, I have around $750.00 to spend on an ARC preamp. The models listed above are all in my price range. Can anyone sort out the sonic characteristics a bit for me, I have no way of auditioning any of these. Balanced outputs are not required. This is the start of a new system, so info on solid state power amps that have a synergy with the ARC preamps would be appreciated as well. Thanks, Marty.
If you are looking for a vacuume tube sound your not going to find it in the LS preamps u mentioned, since they are hybrid designs. I used to own a SP-6B and liked it alot, although working on it is a rather big chore. The 6B has a lumpy frequency response. If you could find an 8B that would be better or a used SP-3 and get it updated when u have more money to spend to a 3C. That has to be sent back to ARC but they totally replace the power supply, tube sockets, coupling caps and volume control as the stock control was a noisy sucker. In this preamp u have defeatable tone controls, a nice feature. It might even drive a high output moving coil, or find a used step up device. BTW Im not a big fan of the SP-9/SP-14 unless their upgraded but they are still hybrids. G.Garfield
I would refer to the LS-2 as the best solid state preamp ARC has made, even though it sports 2 vacume tubes. The line stage is quite a bit more accurate than my SP-8 or SP-10. If a head to head shootout were done on the direct input of the LS-2 versus the line of the SP-10,11, 8, 6 or SP-3,most would find this to be the case. Amazingly, the SP-3A-1 Line stage section is quite a bit more transparent than the 6, 8 or 10 in any iteration.(but coloration is too high) Do I find the LS-2 to be sonically delightful? No,not enough to recommend it.......But, it will more than hold its own against many units at the used asking price. Link it with a D90B series or before 1983 ARC tube amp for best results.
Regarding ARC, I can't remember myself thrilled with any offerings; as John (jafox) I had singled out sp10. The 9 wasn't bad -- but I believe this opinion was linked to its much more reasonable asking price rather than performance...

Not intent on steering you away from ARC, I nevertheless remember comparing a sp10 with that an old mark lev pre at s/one's house. The ML was much better in dynamic presentation and frequency extremes (esp upper). Please note: I "remember".
I CAN'T remember if it was the ML1 or ML7 (probably the latter). I'd expect prices to be similar were you ever to consider such a machine (OTOH, mark lev used different connectors which means you'll have to solder a bit).
The issue of "accuracy" comes in many ways. If we are talking about tonality, tonal coherency, and such, I would agree that the LS2 is more tonally coherent than the SP8 and SP-10 line stages. I owned the SP-10 and realized how compromised its line stage was 10 years later when I went on a quest to upgrade this.

If we investigate other sonic attributes to determine accuracy, the LS2 is so far away from accurate it is not even funny. Listen to a piano, saxaphone, even human voice with the LS2 and take notice of how quickly tones terminate in space. This is not accurate nor natural at all. Notes with the LS2 occupy little to no space; the presentation is very one-dimensional. It only takes me one trip upstairs to hit a piano key and to know a piano does not sound like this.

As much as I wanted the LS2 to work for me, it was such a huge disappointment. Staying with the SP-10, with all of its tonality colorations and such, was easy as it at least conveyed the dimensionality of the performance that the LS2 failed miserably. Fortunately the LS5 came alone and retained the SP-10's strengths and brought on a huge refinement in tonal coherency, frequency extreme coverage, lower noise and thus greater resolution over the SP-10.

We all tend to speak in our own absolute terms. But our comments are relative to what we have owned or heard elsewhere. Had I not owned the SP-10 for many years, and had also not been so impressed with the LS5 vs. LS2 audition at the ARC dealer, the LS2 may have survived less scrutiny. But I also heard the magic in the MFA and CJ preamps and line stages; I knew how flawed the LS2 truly was.

Concerning some comments above, the LS2 uses one tube, not two. The LS1 and LS2 are hybrid designs, the LS3 is all solid state and the LS7 is all tubed.

I have no experience with the ML models as mentioned by Greg, but I did hear the ML38s directly against the LS5, and the ML sound was way way way too analytical for me. The Klyne was much more to my liking and was much less than the ML. The Krell KRC at the time was as dreadful as the ML38s.

For me, a component's tonal coherency only has relevance once it passes through the dimensionality, harmonic structure and decays in a believeable manner. And unfortunately, it is darn tough to find such a product in Marty's price range. The "modify" route would be the way to go here. Marty: you have a tough job ahead of you.

LS-7 wasn't bad as I remember I listened to it before I bought the LS-15. I believe the LS-7 has no remote control though. If that's not an issue, what John recommended with the Dynamicaps upgrade makes a lot of sense. I upgraded the caps in my LS-15 to Dynamicaps and the preamp is a different animal now.