What is the difference between LS & PS


What is the difference between LS & PS on Audio Research preamplifiers.

Ej. LS9 & PS9 (it's for no tubes on line?)

Thank you
Paulo
pauloramirez
hello paulo, i think you mean LS and SP. ls is a linestage only preamp and sp are their preamps with a phono stage.
May I add that SP is stereo pre amp with phono on board. SP-L means line stage only ( no phono input).