Abstract: This disclosure pertains to a public address apparatus comprising a portable dual track tape recorder -- playback unit having individual stationary electromagnetic dual purpose recording and playback heads feeding selectively independently the input of a single channel audio amplifier and speaker system. The audio amplifier is provided with two additional output terminals, each of which is independently capable of providing recording currents to each recording head as desired. Additional inputs are provided accommodating microphones and radio receivers.

Abstract: A sound editing system having a "library" of prerecorded sound effects stored on magnetic recording tape for insertion at selected locations and with a selected quality for forming a final sound track for use in association with a visual display such as a television program is disclosed.

Abstract: A circuit for storing a control signal on a selected length of strip material such as a magnetic tape having a tape head associated therewith and provided with longitudinally spaced marking signals. The circuit includes a control signal generator arranged to be switched on by a control unit to produce a control signal which is applied to the selected length of strip material, and a first detector responsive to the marking signals for switching off the control signal generator when a marking signal is sensed in one direction of movement of the tape material together with a second detection responsive to the stored control signal for switching on the control signal generator during the movement of the tape in the other direction to store the control signal throughout the selected length of strip material, the first detector switching off the control signal generator when the other marking signal is sensed by the first detector.

Abstract: Reproducing apparatus for magnetic tape having a pressure roller mounted on a first movable member and a tape lifter mounted on a second movable member. Solenoid and spring means connected to the first movable member moves the pressure roller between a tape-driving position pressing the tape into frictional driving engagement with a capstan, and a non-tape-driving position spaced from the capstan. Mechanical connecting means between the movable members moves the tape lifter between lifted and lowered positions in response to movement of the first member between its non-tape-driving and tape-driving positions. The mechanical connecting means includes a lost motion connection enabling manual override movement of the tape lifter between its lifted and lowered positions when the first member is in its non-tape-driving position for fast mode operation. This enables manual adjustment of tape proximity to the head, and therefore adjustment of audio output level while editing or scanning the tape in a fast mode.

Abstract: A simulation of the audio characteristics of a commercial broadcast channel is provided to permit the person mixing a master recording to hear the recording as it will be heard by the public.

Abstract: A tape recorder, a clock and a plurality of switches which can be arranged so that the clock and tape recorder can be energized independently of each other or in unision so that the clocck will serve as an elapsed time indicator.

Abstract: In a magnetic tape reproducer, tape lifer bars are rectilinearly movable in one direction by activation of a solenoid to engage the tape and lift it from the heads. The bars are movable in the opposite direction by a biasing spring, when the solenoid is deenergized, so the tape can contact the heads. A cover gate is mechanically connected to the bars and acts as a handle to cause the bars to move the tape back and forth toward the heads.A control circuit includes a normally closed play switch and a resistor connected in series with the solenoid. A bypass conductor parallels the resistor and has normally open fast forward and rewind switches in parallel with one another and in series with a normally closed edit switch. The play switch automatically opens and deenergizes the solenoid, the biasing spring moves the bars out of engagement with the tape which runs forward at play speed while the signal on the tape is reproduced through audio output means.

Abstract: Recording and reproducing apparatus is disclosed wherein stereo signal components which include a monaural signal component are supplied to a signal processing circuit. The signal processing circuit replaces the supplied monaural signal component with a further monaural signal component. The thus processed stereo signal components, including the further monaural signal component, are supplied to a first recording head for recording on a medium. The supplied stereo signal components including the supplied monaural signal component are coupled to a second recording head for recording on the medium. The recorded stereo signal components including the further monaural signal component and the recorded stereo signal components including the supplied monaural signal component are reproduced from the medium and sounds corresponding to the reproduced signals are generated.

Abstract: A method of and apparatus for mixing and recording multitrack stereo audio signals from individual audio signals while utilizing the development of analog signals which are indicative of level, etc., converting the signals to digital form for clock controlled processing and reconverting to analog form to actuate mixing control elements.

Abstract: A tape marker for a tape playing machine in which tape runs past a reproducing head in a housing compartment. The compartment has a door through which tape is inserted and withdrawn when the tape is changed or edited. A marking arm having an inked marking pad is pivoted to a sleeve which is mounted on a removable compartment cover so the tape marker and cover comprise a unitary sub-assembly. A pushbutton guided in the sleeve is connected to the marking arm by a double-pivoted link. Manual depression of the pushbutton swings the marking arm to press the ink pad against the tape. A narrow rib on the tape side of the pad prints a line on the tape at the exact center of the reproducing head. When the pushbutton is released, a return spring moves it outward and swings the marking arm and pad to a stored, out-of-the-way position providing clearance for the tape when inserted or withdrawn through the door.