Block Diagram of Magnetic Tape Recording | New Topic

In this note, we are going to know about the Block Diagram of Magnetic Tape Recording System. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

Block Diagram of Magnetic Tape Recording

Figure shows a typical tape recording and reproducing system. This system uses independent amplifier stages for recording and playback.

Here is the block diagram of tape recording system and the function of various blocks of this system is described below

• Microphone: Microphone is a transducer. Here, it intercepts voice signals(sound) and converts it into electrical signal called audio signals.
• Pre-amplifier: The audio signal output from microphone is fed to the pre-amplifier stage, it boost up the signal to make it compatible to processing circuit.
• Processing circuit: This circuit controls the gain and the level of recording in record section. It also provides pre- emphasis and de-emphasis for low frequency and high frequency audio signals for noise reduction.
• Driver amplifier: This block gives further voltage amplification to the signal so as to reduce the internal resistance of power amplifier and hence, to drive it to give power amplification.
• Power amplifier: This stage provides adequate power boost up to the audio signal to drive the record head.
• Filter: The main function of filter circuit is to pass the bias oscillator’s signal to go to the amplifier as it will unnecessary get overloaded.
• Heads: There are two heads in this section, erase, head followed by a record head. The erase head is used to erase all the existing contain, while the record head records audio current in form of varying magnetic field in the magnetic material of the tape. During playback the same head is used for playback. In professional Hi-Fi recording, separate heads are used for recording and play back.
• Record/Play Switch: With the help of this with record or playback operation is selected. If record is selected then, signal is fed to recording amplifier otherwise the signal is fed to the pre- amplifier for playback operation.

During playback operation, the reverse operation is performed i.e., the audio signal retrieved from the magnetic tape is passed through pre- amplifier, processing circuits, driver amplifiers and power amplifiers and finally the signal is fed to the loudspeaker for reproduction of sound.