Vinyl records produce analog sound through a mechanical and analog process that’s fundamentally different from the digital audio produced by modern formats like CDs and streaming. Here’s a breakdown of how vinyl records generate analog sound:
- Recording and Cutting: The analog sound on a vinyl record begins its journey during the recording and mastering process. Musicians and audio engineers use analog recording equipment to capture sound waves. Analog signals represent the continuous variations in air pressure caused by sound, as opposed to digital signals, which sample and quantize these variations.
- Mastering: The analog recording is then mastered, where the sound is further refined and equalized for vinyl production. During mastering, the analog signal is fine-tuned, and various adjustments are made to ensure the best possible sound quality on vinyl.
- Vinyl Cutting: The mastered analog audio is transferred to a lacquer disc in a process known as cutting. A cutting lathe is used to physically engrave the audio onto the lacquer, creating a continuous spiral groove that contains the analog sound information. The width, depth, and spacing of the groove correspond to the amplitude and frequency of the audio signal.
- Master Disc and Stamper Production: The lacquer disc, once cut, is used to create a master disc. From this master, metal stampers are made. These stampers are used in the vinyl pressing process to replicate the grooves onto vinyl records.
- Pressing Vinyl Records: Vinyl records are created through a process called pressing. The stamper is placed between two pieces of heated vinyl, and hydraulic pressure is applied to mold the vinyl into the shape of a record. The grooves of the stamper are imprinted onto the vinyl, creating the analog sound information on the surface of the record.
- Playback with a Turntable: To listen to the music on a vinyl record, you need a turntable. When you place the vinyl record on the turntable and drop the stylus (or needle) onto the groove, the analog sound is retrieved. As the stylus moves along the grooves, it vibrates in response to the variations in the groove’s shape. These vibrations are transmitted through the tonearm, cartridge, and ultimately to the amplifier.
- Amplification and Playback: The electrical signal generated by the stylus vibrations is extremely weak, so it needs to be amplified. The phono preamp or phono stage in your audio system amplifies this weak signal. It also equalizes the sound to reverse the RIAA (Recording Industry Association of America) curve applied during mastering to reduce noise and improve sound quality.
- Conversion to Sound: The amplified analog signal is then sent to your speakers, where it’s converted back into sound waves. The movement of the speaker diaphragms corresponds to the variations in the analog signal, producing the audible sound that you hear.
In essence, vinyl records capture and reproduce analog sound by directly translating the continuous variations in air pressure (sound) into physical grooves on the vinyl surface. The playback process reverses this transformation, converting the physical groove movements back into electrical signals, which are further amplified and sent to your speakers to recreate the original sound. This analog sound reproduction process results in the warm and rich audio quality that vinyl records are known for.