Tube Preamp - What to buy?

You will find that the selection of preamps with tonal controls and a built-in phono section to be very limited. If you could consider a line stage with an outboard phono preamp you will find a much larger selection to choose from. If you choose to go that way you can find a good solid used tube line stage and a decent used phono preamp that will equal or exceed most built-in phono preamps well within your budget. Just remember this when buying used tube equipment, many people who own tube equipment are tube rollers, usually when they sell there equipment they swap out there expensive and matched tubes for lesser quality and unmatched tubes thus reducing the sound quality of the equipment by sometimes a large margin. So be prepared to include in your budget the price of new tubes, which for preamps or line stages is not much but amps on the other hand is a different story.

Sound advice from @millercarbon! $2500 is the range of many fine integrated’s. Solve your amp problems. Buy an integrated. I bought a Willsenton KT88 for $1280 delivered. I spent $600 on tube upgrades. It drives my Martin Logan Spires just perfectly. What does $2500 buy today besides a used BAT. That wouldn’t be bad but I wouldn’t invest that kind of money into a 20 year old preamp. Buy new and save some money. Buy a tube integrated! It’s all the power your speakers need, imo. 

Conrad Classic 2 SE. This preamplifier has upgraded Teflon Caps and Vishay Resistors along with a precision Alps Volume control. Unfortunately it does not offer a remote or a phono section. If you are moving towards separates then the lack of a phone stage should not bother you however the lack of a volume remote might. This unit sounds incredible and falls within your budget. I lived with this for a long time before upgrading and did not mind the lack of remote, but not everyone would accept this.

I am a big Audio Research fan so am a +1 for AR.  Find where in the line you can afford today and upgrade later if you love their sound.  You should be able to get an LS17SE line stage for about $2000.  You won't be able to stay within budget with an AR phono so maybe start with another brand.  The LS17SE is a well regarded line stage that would be able to support many other high end components as you build the system.  Another option would be to get one of their solid state line stages, such as the LS3B with remote.  They are not that common but I started my AR journey about 4 years ago with one for $850 and sold it last year for $800.  This would allow you to also get an AR phono such as the PH5, which should go for around $1300.  I used them with my AR Classic 120 mono blocks and they worked very well together.  Have fun trying out components!

Along with my recommendation of the Erhard Audio Aretha tone control pre-amp w/phono (had for ~year or so now) wonderful sounding, super clean & clear, made in USA, affordable with strikingly good old school looks. I'd recommend that you consider the system matching before purchasing. These boutique products sound good and can be great with used within the same line. Oh...and mine has a loudness switch that I'll take all the way to the bank!