So what exactly was the Astraltune Stereopack?
On the company's Trademark application, it is described as "a portable stereophonic tape deck, headphones and battery sold as a unit and mounted in a pack."
This description is pretty accurate. Basically, the Astraltune was an automotive-style stereo cassette deck, mounted in a hard plastic case along with an array of five General Electric NI-CAD rechargeable batteries.
The deck slid into a padded nylon pack, which had two shoulder straps and a waist strap and was meant to be worn against your chest.
A velcro flap covered the top of the pack, which when opened gave access to the cassette door, eject/fast-forward buttons, and the volume, tone and balance controls.
The whole unit weighed in at about 3.5 pounds, and measures about 8 inches tall, 5 inches wide, and 3 inches thick. The batteries could power the unit for about 5 hours.
The orange Sennheiser headphones supplied with the unit were meant to hang below the neck, rather than over the top of the head as with most headphones of the time.
The headphones connected to the deck via a 1/4-inch headphone jack at the base of the deck.
Optional accessories included a home adapter, a car adapter, a speaker adapter, over-the-head headphones, and a twin headphone adapter.
There were three generations of the Astraltune. The first generation was a car stereo unit made by Sanyo (the FTC1 model), and the second generation was a different car stereo manufactured for the company by Yams Electronics.
In the early 1980s, the third generation of the Astraltune appeared. It featured a smaller, lighter tape player with a flip-top cover for the controls. It also included an AM-FM radio and a metal tape setting.