I recently built this pair of 5 watt, pure class A mosfet output mono blocks designed by the master, Nelson Pass. The "Amp Camp" amp kit is available from the DIYAUDIO webstore. The enclosures are made in Italy and the parts quality is very good. Dale resistors, a solid circuit board, etc. The sound is typical low watt Class A Nelson Pass. Several users who own the First Watt F5 report these mono blocks sound very similar. I thought they sounded great, but preferred the sound of the TPA3116 amps.