Best Pre-amp for $500??

The mod squad duluxe line drive used is good in this price range

I would look at the MinuDSP 2X8 HD. It's a preamp, DAC and MiniDSP all in one. It sounds great and any remote will work with it.

I would choose a Dynaco PAS 4 preamp with phono stage. Great preamp!

I would go with George suggestion and get a 5-6 year old $3,000 avr that they are selling for nothing because it has no HDMI instead of paying a ridiculous 70%-80% of new price for a unit that had a 70% mark up to begin with

There are at least 5 processors close to your price range like that listed here right now. They have same or much better DACs or twice as many DACs than used stereo pres that people want 5-10 times as much for. Plus you could use them for audiophile audio in 3-4 rooms at the same time with amps. Or just run hdmi to your tv and digital out back to receiver and you have everything the new models have and more.  lis758ec    lis761c4    lis75623