More than a few of us at Metropolitan Acoustics are vinyl record enthusiasts. Vinyl is a true survivor, having outlasted all of its would-be physical media successors. Ultimately, not even the digital compact disc could dethrone the analog ambassador of high-fidelity. Streaming services and compressed audio deliver us fast-food quality music that gets the job done when we are in a rush or on the move, but the ritual of laying down the needle to the groove has yet to be outdone. Read on to learn more about how vinyl and the turntable bring warm music to our ears.
Analog vs. Digital Signals
Sound arrives at our ears as an analog signal, a continuous function in time. While vinyl records store the signal in its original analog state, digital media aims to recreate the analog signal as a discrete function, which can be thought of as distinct steps. The following figure shows an analog signal in gray and the attempted digital replication of the signal in red. In practice, the digital steps are so short in time that it is difficult, or perhaps impossible, to tell the difference between a digital and analog signal; however, this claim will likely be debated in perpetuity. Digital recordings do have a considerably lower noise floor than vinyl records, which inherently have flaws from the manufacturing process and wear from playback. The signal-to-noise ratio for CDs is around 90 dB as compared to 60 dB, at best, for vinyl. However, even with vinyl’s higher noise floor, the analog signal is still there in all its glory; some argue that the noise associated with vinyl is an integral part of its characteristic warm sound.
One Needle, One Groove, Two Channels?
One of the most important components of a turntable is the needle, otherwise known as the stylus. The grooves of a record move the stylus which in turn moves a magnet and coil set to convert the signal into electrical energy to be used by the amplifier. In early years, all records were mono; the analog signal was pressed onto the vertical walls of the groove and the stylus moved horizontally. In the 1950s, stereo records were introduced by taking advantage of the V-shaped groove. The right channel was cut into one side of the groove and the left channel into the other. Instead of moving horizontally, the stylus is forced to move diagonally, either up and to the left or up and to the right, thus creating two separate stereo channels. The separation of the channels is limited to around 25 dB since there is only one stylus contacting one groove. Again, this limitation is part of vinyl’s charm; it can be argued that the superior channel separation offered by digital formats results in a sound that is too clinical.
Playing music through digital means has its advantages, but there is a reason vinyl has stood the test of time. If anything, it takes the music we typically relegate to the background of our busy lives, places it in our hands, and allows it to shine in the foreground, deservedly so.