Audio Research preamp LS vs SP

Any other specific meaning for the one or two digits after LS and SP. I assume the bigger the digits, the later the model is and more expensive. Any other meaning? For example, Can you distinguish a tube preamp or a solid just by looking the numbers?

Jeromexzh, as far as I can remember, the SP line is an older generation of preamps and they included a phono stage. Some of them are classics (SP10, SP11). The first LS models have appeared around the early 90s. These models are only line preamplifiers (no phono).

You can't distinguish a tube or a solid state preamp just by looking at the numbers. Like you said, for the current line, the bigger the digits, the later the model is and more expensive.

Pay attention if you compare a discontinued model like the LS5 with a new one like the LS12. You may think that the LS12 is better than the LS5 if you just look at the numbers. The LS5 was the high end of his generation while the LS12 is the low end of the current generation.

Cheers. Daniel

Beaudoind is right, the SP series have phono stages, and the LS series are line level preamps only. Most of the SP series do not have remote control capability, whereas the LS products do. As for the model numbers, well, the higher numbers are the most recent but not necessarily the best ARC has/had to offer. Jeff