ARC LS-5 vs SP-10/11 for Plinius SA-102

Need a preamp for my new Plinius SA-102. The Plinius is expensive and my budjet for a preamp is therefore small. I am aware that classic ARC preamps (tube) are still very good. After reading some reviews and threads I have concluded that ARC LS-5 and SP-10/11 are the most interesting models. The SP-10 seems to be the best (is it?). But I really need a word of advise here. I am not using a turntable so phono is not an issue. So, according to you, which one among these preamps is a better match for the Plinius (and why)? Thanks.
Having heard all three in familiar circumstances, I think the LS-5 would be my choice, given that you don't need a phono section. The LS-5 seems to my ears to balance the glorious classic tube sound of the SP-10 with the accuracy of the cooler, more neutral SP-11 to give a better overall presentation (kind of a best of both worlds thing). I've always felt the LS-5, particularly the revised versions of it, is one of ARC's best products, and a little underrated. Plus if your Plinius has balanced inputs, the LS-5 has balanced outputs, as I recall (you can get a balanced output from the other two using the inverted and main outs with some adaptation of your interconnects, I think, but it's a hassle).
According to your statement, the LS-15 seems to be a fine choice. In your opinion, are these classics good enough? I ask because this preamp will meet the newest (and the best, IMHO) Plinius power amp and a couple of Sonus faber Cremonas... You also talk about revised versions so I ask: what about the earlier versions, are these still a good bet? The Plinius has balanced inputs, yes. Thanks! Keep in touch.
I have not heard the SP10, though it is apparently wonderful. I don't know if it had balanced outputs, but I doubt it given its release date. I owned the Ls5 MKII, and it was fantastic. I have not heard the earlier MK I versions. Also, It is available with a remote volume control. I have seen a couple of these on Audiogon during the past month or so, for around $2000 which is a bargain.
Good luck
ARC LS-5 II is one of the most musical of all preamps
on the market. It can also be upgraded to reference
standard through the Great American Sound Company.
tgm: Don't fall in the "newer is better" trap that the manufacturers and mags would like you to believe. My Jadis preamp is from 1995, my Jadis amps from 1990 and I'd stack them up against anything out there. While there have been improvements in parts over the years, ARC is good about updating their units and bringing them up to spec when you send them in for a checkup, and Brauser's point about upgrading through Great Northern(?) Sound Company--I'm thinking of Steve Huntley--is a good cost-effective way to bring a fine commercial design such as the LS-5 (not the 15, I've not listened to that one at length, I presume that was a typo) up to state-of-the-art status if you really want to. I'm not sure how it will sound mated to the Plinius amp, as I've not heard that combination, but in my prior listening with this pre and other ARC preamps they fed solid-state amps with no problems whatsoever. As Blauser says, the LS-5 is a very musical preamp, I think that would be ideal with your speakers, which are designed more for the music lover rather than the "boom and sizzle" crowd.

I have commented over and over here about the LS5 II and III and also the SP10. I owned the SP10 for 8 years in the 80s. It was a wonderful preamp for LPs but its mediocre line stage was not worthy of CD playback. And no doubt the line stage affected the ultimate performance for LPs too.

I changed to the LS5/PH2 combination which had all of the magical bloom of the middle octaves but brought on much refinements at the frequency extremes. And the SP10's high noise level as well as much older parts I am sure had much to do with its not very impressive resolution. The LS5/PH2 had much more low level detail. I owned this combination for 7 years until I moved onto the BAT VK31SE/VKP10.

The LS5 MK II is wonderful but it has an exaggerated top end, too much sibilance, which can be an annoyance once you hear the refined MK III. I had both in my home for a few weeks until I sold off the MK II. Contrary to what I have read by others, I heard no differences between these too in the mids, harmonic richness, ambience, etc. The MK III's top end is simply more natural and not fatiguing. But the MK II had a little more bass definition or extension. Whether this was accurate I can not answer. But in either case, since you are not using phono, the SP10 would absolutely be the wrong move here. I know of people who use the SP10 strictly as a phono stage and then drive it into another line stage.

The MK II has 30db of gain which only might be needed for phono users. The MK III comes either as 12db or 18db which is set at ARC or can be changed through resistor kits.

Stay away from the LS2, LS15, LS22. These are not at all in the same league as the LS5. All ARC preamps are not alike!!!

I agree with almost everything Jafox says, except the part
about the LS5mkII vs LS5mkIII. I prefer the mkII version to
the mkIII version. I've had the LS5mkII in my system for
almost 8 years now (driving two ARC D-400mkII SS amps) and
have had no desire to upgrade to the mkIII or Ref1/Ref2
even though I've had all of them in my system for extended

Jafox notes a fatiguing top-end for the mkII in comparison
to the mkIII. I couldn't disagree more. Neither has a
fatiguing top-end according to my own listening. The main
difference I noticed was a slight lowering of the noise
floor in the mkIII but with a reduced sense of bloom and a
slight flattening of the soundtsage depth (width did not
seem to be effected). Both versions did outstanding bass
(f3 on my Kinetic TLs is 16Hz so bass performance is very
important in my system).

The mkII has switchable 12/30dB gain. The mkI version is
essentially the same as the mkII except the mkI had a design
glitch which caused a 10dB increase in the noise floor at
the 12dB gain setting vs. the 30db gain setting. The mkII
fixed this glitch. You definitely do not want an mkI version
unless it has been upgraded (fixed!) to mkII.

The other advantage to the mkII vs mkIII is that you can
upgade the mkII to mkIII if you are dis-satisfied for some
reason with the sound (can't imagine you would be). You
can't switch an mkIII back to an mkII.