Many of the features once found on separate amplifiers and tuners, or on the highest-priced receivers, will be showing up on lower-priced models due to arrive on dealers' shelves in the coming months.

In tone controls, for instance, more units will be sporting, in addition to the traditional bass and treble adjustments, a third control for the midrange (sometimes called a "presence" control). Beyond this, some controls will permit adjusting not only the amount of boost and cut, but the frequency at which they take place. In some sets the tone-control arrangement approaches the capability of an elaborate equalizer, with as many as five separate frequency bands for a more precise tailoring of the sound than is possible with the older tone-control facilities.

Many new units will contain signal and power indicators in the form of light-emitting diodes (LEDS), or fluorescent bars, or the old-fashioned but still reliable meter-with-pointer. For the serious tape-recordist, of course, such indicators are a must in monitoring signal levels so as to get an ample signal onto the tape while avoiding overload and distortion. For just listening, the power output monitors may be a bit superfluous but they can convey an idea of how amplifier power relates to the volume of sound in a given room, and they also can alert you to possible over driving of your particular speakers.

Digital readout is showing up on more tuners, both separates and those that are part of a receiver. At the least, this feature can make it easier to tune in stations. Actual digital tuning, whereby a special circuit takes over the selecting of a station, can make for extremely accurate tuning.

A number of new units will include a built-in "pre-preamp" for handling moving-coil phono cartridges. These pickups, with their characteristically low signal output, have required special boosters connected to a conventional phono input. With many of the new sets, connecting a turntable fitted with a moving-coil pickup will be no more difficult than using any other kind of pickup.

Another connecting convenience is the "circuit interrupt" feature. A special pair of signal jacks at the rear makes it easy to patch in an accessory device -- such as a graphic equalizer or ambience enhancer -- and return the "processed" signal, or part of it, to the same amplifier or receiver. This bit of sophistication once was feasible only with separate preamps and power amps. Note: Some of these outboard processors can be connected into the tape-monitor loop of a receiver, but then you have to remember to use the tape switch on the new device to play tapes through the system.