1959 LOW-NOISE G.E. 6072 = WORLD’S BEST 12AY7 sub. This is the ULTIMATE cream-of-the-crop of the G.E. USA LOW NOISE 6072 TUBE! THE HOLY-GRAIL OF THE G.E. 6072 CLASS OF PROFESSIONAL 6072 AUDIO TUBES – THE G.E. “BLACK-PLATE 6072” is a designation for LOW NOISE the Reference-Standard of the 6072!