Best tube preamplifier for under $15k

Lots of choices to consider. 

I would suggest checking out the Thomas Mayer 10y Line Preamp. I think this is one of his best known products. 

Each unit hand built to your specs by him personally. You can select for what combination of inputs and outputs, chassis wood and paint scheme, he may also give choices on input and output transformers. It can run 10y VT-25 tubes, 801a VT-62 or his own Elrog 801a tubes.
Also transformer volume control is standard which is very rare. The build quality and parts selection are at the highest level. If you are outside the EU you can deduct the 19% VAT from the price. To the US and without pricey options it would cost about $10k. https://www.vinylsavor.com/en/products/line/

His all silver and differential models cost over $15k

JUst wondered how you guys would rate the Accustic Hybrid Pre.
Thanks

Cary Audio SLP-05 with the Ultimate Upgrade.  List price is just shy of $11,000; however, through Carydirect.com, you can purchase it for just under $7,000.  With the money you’ve saved, I’d upgrade the eight (8) stock 6SN7 tubes.   

Are you all crazy!  Everyone knows that AR SP10 is one of the top Tube Pre Amp of all time, for some, the best there EVER was! They can be had for around 5k, if you can find one!

So I ended up with the MicroZOTL and am very pleased with this preamplifier. The 12at7s required changing out and after some rolling decided on some RTN east german tubes. The NOS 12SN7s are actually quite good. I don't find the preamp super warm at all, but open sounding with good liquidity. 

Paired with the Ampzilla, 2nd Edition yields a very pleasing, dynamic combo. I'd love to try a Vac Ren V at some point too, but in no hurry now.