Audio Research Preamp Experts?

Can you clarify also what would be considered a worthwhile upgrade from sp16 and why?

Thanks.

Minor1, SP-15 is different, no tubes in the line stage.

SP-11 MKII is the better choice.

The LS-5's are extremely high-value preamps, particularly if your system is balanced.

The LS-3 is one of the great "cheap" preamps available used, especially, as the above poster notes, if it is used through its direct input. Me and my dealer preferred it to the LS-2b. I bought one fifteen years ago and while it's been out of my system for many years now, I pull it out every now and again - it sounds really good for a moderately priced preamp, and is one of the very few moderately priced solid-state preamps that sounds really good.

The LS-3 is very very good for the money...

Key words, "good for the money". That's like saying its in great condition for its age.

I just noticed the high asking prices on SP-11 MKII preamps. If these are merely asking prices and not an indication of actual price the SP-11 is still a solid recommendation, but I would think long and hard before spending $5,000 on a 25 year old preamp that will soon cost you a fortune in maintenance.