I purchased a used MFA Magus A in 1995 - never gotten rid of it. I use it exclusively as a phono stage now as the Conrad Johnson's of the world have overtaken it's line stage. In 2003, I had Scott Frankland redo it - new capacitors, new pots, new jacks, modifications to the power supply etc.
It responds well to tube choice. For the 12AT7, use a Amperex or Mullard. ECC801S or 6201 can be used as well. The 12AX7's should be Electroharmonix or Mullard. ECC 83 can be used, particularly the Telefunken. Also good are 5751's from Jan Phillips or Raytheon. Military spec 5751's are much cheaper and more plentiful - Sylvania, Raytheon, or RCA.
It's great with a CJ Premier 16, ET3 or 5. It can grow with you. Someday I'll get a Wavestream Kinetics or TEA 1 but until then, the Magus is great.