I own the original deHavilland Aries SET 845 mono block amps-25 watts x 2, paired with deHavilland Verve 6SN7 tube preamp & 1983 Klipsch Cornwalls. It is my favorite amp sonic wise that I own. The deHavilland Aries G model is the 30 watt x 2 new & improved model. Have not heard other 845 SET amps, so I have no reference of comparison.
I also own Welborne Labs SET 2A3 Moondogs mono block amps with ultimate upgrade parts-factory assembled, Welborne Labs Reveille 6SN7 tube preamp-factory assembled. Mcintosh MC7150 autoformer power amp, Mcintosh C38 preamp & Llano Phoenix CAS 300/VA2 mosfet/tube hybrid power amp. VA2 voltage section uses 6SN7, 6SL7 & 12SN7 tubes. Currently using 12SX7 tubes in the VA2. There are 2 outputs on the Mcintosh C38 preamp & I have both the Llano and Mcintosh amps hooked up. I bought a George Wright AU-1000 12BH7 tube preamp off of Audiogon earlier in the week. It has not shipped yet. I am going to use the Wright preamp with the Llano Phoenix amp.