"phase 4 stereo" can only be described as a marvel of sound, a radically new and dramatically potent concept in the art of high fidelity reproduction. It is London's trademark for the most advanced and flexible of all stereo recording techniques; it stands for motion and an uncanny sense of spatial realism unapproached by çonventional disc standards; it is your assurance of unmatched quality control, rigorously applied from studio to finished disc, throughout every single step of the manufacturing process. Perhaps the most remarkable innovation of "phase 4" is the use of London's custom built 20 channel console mixer. This complex and forbidding-looking machine permits sounds from no less than twenty separate sources to be combined and blended in precise perspective. Each instrument can be pinpointed at exact locations from extreme left to extreme right along the horizontal plane, or forward and back through an astonishingly large depth of field. This, of course, is only part of the "phase 4" story. The making of the master tape, the cutting of the master lacquer disc, production of the final copy for the consumer -all are done with custom equipment, under the constant supervision of both engineers and musicians. The statement that the 500,000th record produced is identical in sound performance with the very first copy pressed is no idle boast: it is part of the unique and proud credo of "phase 4 stereo".