Major Japanese electronics companies have pledged to put the first digital tape recorders for American consumers on store shelves this summer, boosting the technology of recorded music to a new level.

One of the firms, Sony Corp., will go a step further to promote the new home music medium: using a recently acquired CBS Records unit to issue prerecorded digital tapes for the machines.

Sony said it will offer two models of the machine, at suggested retail prices of $900 and $950. Blank tapes will carry suggested prices of $12 to $18 and prerecorded tapes -- 10 classical music titles will be available from Sony initially -- will list at $19.95.

Other equipment brands to go on sale are JVC, Technics, Denon and Onkyo, carrying somewhat higher suggested prices. Announcement of the sales plans were made at the Consumer Electronics Show, a mammoth trade gathering that convened in Chicago on Saturday.

Digital tape recorders produce the same crisp music as compact disc players by converting sound into the precise ones and zeroes of computer language. Unlike CDs, however, digital machines can record and copy music in the home. Manufacturers hope they will bring on yet another revolution in home entertainment and a multibillion-dollar cycle of sales.

Introduced in Japan in 1987, the machines have been kept out of general markets in the United States because of threats of legal action by the Recording Industry Association of America, which contended the machines would lead to mass pirating of copyrighted materials.

Last summer, manufacturers and the recording industry reached an accord to limit the machines' copying abilities using built-in circuitry: Owners will be able to record directly from compact discs or prerecorded digital tapes but will not be able to copy the copies.

About 1.7 million conventional cassette decks are sold each year in the United States, according to the Electronic Industries Association, making them the favored medium for home music. The question now is whether large numbers of Americans will find the new machines worth their considerably higher cost; prices are expected to come down if the machines catch on.

Marc Finer of Communication Research Inc., an industry consulting firm, predicted the machines will be "very, very well-received." People who now buy high-end conventional decks will be the first to buy, initially copying their music from CDs, he said. As more decks are bought, major record companies will issue prerecorded labels, he suggested, in turn quickening the pace of equipment sales.

In 1988, Sony bought the largest U.S. record company, CBS Records. Sony is now trying to promote the digital medium by offering prerecorded classical labels through Sony Classical, formerly a CBS classical division. According to Sony, CBS Records as a whole has made no decision on whether to go with the digital format.