Who out there knows about Audio Research Pre's???

I agree with tubegroover's recommendation on the SP8 & SP10. I got an SP6C1 with the muting circuit moded. The C1 uses 12ax7 (4) and 6dj8 (2). The 6dj8 has about an 8 db better signal to noise ratio over the 12ax7. Mine is fairly quite running a low output MC. The tubes used on the preamp makes a huge difference. I did lots of tube rolling with Mullards, Telefunkens, GE, Amperex...etc.

Well, I have a ARC SP10II AND a Mesa Baron! That said, the pre-amp you pick will be determined by what tone you expect to get. The Baron is neutral and can be more like SS except for the presence of tube air and spaciousness. I like my system to err on the warm side and would not recommend an ARC amp later than the SP10II - I'd look at SP8II the SP6 (latter models) and if you want classic ARC warmth, and can give up a bit of resolution, the SP3. If you don't need a phono stage, I would suggest that you listen to an EAR 834L. They are cheap, easy to tube, and sound much like they SP10 (in fact except for the bass, which is better in the EAR, they are incredibly close). I use one in a second system. The differences in ARC pre amps has been discussed at length and accurately in the Audio Asylum forum and I would suggest you do a search there.

My two cents:
I have an LS2B mk2. Used for $750.00 on audiogon and is a terrific value. the amp is a music reference rm 200, audio aero 24/192 mk2 cd player, vpi scout tt, pass labs xono phono, audio physic virgos, nordost spm, quattro fil and silversmith cables. the LS2b offers great resolution, a big soundstage and it's noise free as well. I don't think you have to pay the LS22 or 25 dough to get the performance. good luck!

any input on the sp16 l

I have listened to both the SP-10 MK2 and SP-11 M2, clearly the two best vintage preamps from ARC. I find the SP-10 MK2 to sound warm and tuby, and when compared to the SP-11 MK2, it lacks the high & low end extension and sound a bit too syrupy & dense in the midrange. However, when matched with a leaner system, it could sound very inviting. The SP-11 MK2 has a cleaner, bigger, faster, more detailed and more dynamic sound. Its midrange is more neutral (just a bit tuby) and very liquid, but not emphasized like that of the SP-10 MK2. Furthermore, the SP-11 MK2 in terms of bass slam depth and speed is far more impressive. Overall, the SP-11 MK2 has a more linear sound with a blacker background.

The better preamp? I believe that it depends on what you have. If your system, independent of the preamp, tends to be lean and/or bright, the SP-10 MK2 may be your road to salvation. If you have a rather neutral or warm sounding system independent of the preamp, I would prefer to go with an SP-11 MK2.