Preamp recommendations for under $600.00


I would appreciate a few Preamp recommendations for under $600.00. Could be new or vintage, SS or Tube. Thanks in advance.
laketahoejon
I would recommend a used Conrad Johnson also per Mofimadness. You know it will match your amp, and they sound spectacular!
Post removed 
Thank you Viridian. Interesting idea. How many hours of assembly does the Smash (or the TSGG) take, and does one have to be a very skilled with the solder gun?
Post removed 
Get an Acurus L10 or R11. These are known as good quality pres that have good mil spec components and can be upgraded easily and with great return on investment. Mine cost me $250 used. Do a Google search and you will find reviews on them and that they are popular among budget audio lovers.