When comparing 78, 45, and 33 RPM records, the immediate distinction that comes to mind is the speed at which they rotate. While this is indeed a significant factor, as revealed in a recent video by [Techmoan], playing 78 RPM records involves more nuances, especially those of the older variety lacking ‘microgrooves’. Even if your record player supports 78 RPM speeds, you may have noticed that the sound quality is subpar, often plagued by clicks and pops.
The main reason behind this discrepancy lies in the width of the grooves on a typical 78 RPM record, which is 3 mil (thousandth of an inch) wide, compared to the slender 1 mil wide grooves found on microgroove and 33/45 RPM records. This disparity affects the stylus tip, which is significantly undersized for the wider grooves, causing it to struggle at the bottom while missing out on the details etched higher up on the sides. This explains the historical use of flip-style styluses, as shown above.
Today, you can acquire mono 3 mil styluses from reputable brands like Audio-Technica, allowing you to switch the stylus cartridge between sessions with different groove sizes. As demonstrated by [Techmoan], the difference between using an ill-fitting stylus and the correct one is remarkable, highlighting another playback challenge: equalization.
In a typical scenario, records undergo equalization during the recording process to compensate for the medium’s imperfections. During playback, this equalization effect is reversed, aiming to restore the original signal. Since 1954, the RIAA equalization standard has been widely adopted, and most record preamplifiers assume its usage. Consequently, older records may not align with this standard, as each publisher often employed its unique equalization.
In the video, [Techmoan] discovers an affordable method to play wide-groove 78 RPM records and bypass the RIAA equalization by directly tapping into the cartridge signal. While achieving this goal might be easier with a bigger investment, where is the fun in taking the easy route?
Image Source: Victrola
