From the flyer titled "MOOG MUSIC", R.A.Moog Company, 1964

Careful integration of solid state circuitry, wide-range loudspeaker of high efficiency, rechargeable battery, and lightweight enclosure, characterize the model PMS-15 amplifier-loudspeaker combination.

The PMS-15 is an integrated amplifier-loudspeaker capable of clean, accurate reproduction, yet completely portable and self-powered. When combined with signal sources such as portable radios, tape recorders, phonographs, microphones, and musical instrument pickups, the PMS-15 becomes a truly universal music system. For home use the PMS-15 can be connected and operated as a conventional hi-fi system. Its brown leather-like case fits into any decor. The instrument may be set against a wall or on a shelf so that its controls are readily accessible, but power and signal cords are out of sight. By simply disconnecting the power cord, the instrument is ready for high fidelity reproduction wherever it is taken. For musicians, the PMS-15 is an ideal instrument amplifier. The performing musician is no longer restricted by an amplifier power cord. For professional enterainers, the PMS-15 combines all the advantages of a portable public address system with those of a high fidelity amplifier.

Amplifier chassis, loudspeaker, and rechargeable battery of PMS-15 are housed in an attractive molded enclosure.
For people who travel, here is an amplifier-loudspeaker that provides uncompromised high fidelity reproduction of their favorite music, anytime, anywhere.
To make possible a high-quality high fidelity amplifier which may be conveniently carried and operated independently of conventional power sources, new design concepts are employed. The resulting instrument embodies several departures from conventional circuitry, and other design features that combine conventional components and circuitry in novel ways. By Re-examining design and construction standards which are now standard in high fidelity equipment, all the features of the PMS-15 are incorporated in one instrument without sacrificing quality of reproduction and reliability of operation.