Phase Linear 300 Series Two Amplifier 

Currently up for sale: www.ebay.com/itm/Phase-Linear...
The Phase Linear 300 Series Two amplifier was produced 1979-1982. The PL 300 S2 was the (improved) replacement for the 200 Series Two. The difference being the 200 S2 had total harmonic distortion (THD) and intermodulation distortion (IMD) at a very good .09%, while the 300 S2 has a ridiculously rating of just 0.002% THD and 0.005% IMD! These ratings...and of course it's strong high-current power and absolute clarity across the frequency range (11Hz to 190kHz!) makes this amp sought after by audiophiles today.
Other equipment: Atma-Sphere UV-1 preamp, Marantz CD6006 CD player, ELAC Adante AF-61 loud speakers. (Media: Redbook CD)