Head amps are devices used to separately amplify moving coil cartridges to the same level as moving magnets. They can be built from active electronics with power supplies or simple step-up transformers. They are needed because moving coil cartridges typically have outputs thirty times lower than their moving magnet brethren. Why they are separate has always been intriguing to me.
Moving coil cartridges have been around for many decades. I think it was in the late 1940s that Danish company Ortofon started selling moving coils, but for the most part, turntables and records were played primarily on moving magnet cartridges. From my memory, it wasn’t until the 1970s that moving coil cartridges like the famous Koetsu made their presence known and the need for head amps became the hot ticket for manufacturers.
PS Audio made its first head amp, the MCA, in the late 1970s. Not long after its introduction we also outfitted our preamplifiers with the ability to play moving coils without aid of a separate head amp, but that was rare.
Ron, from Hayes, Va., asked me a good question about head amps in this video about reducing vibrations. “Why don’t they just build head amps into the turntable’s headshell?”
This is a great idea because it eliminates the need for separate boxes, power supplies, connecting cables. But that’s also the problem. Unless the head amp is a passive transformer, you still need most of that stuff to make the circuitry work. Moreover, most head amp manufacturers aren’t the ones building turntables, arms, and headshells.
But the notion of miniaturizing the sensitive electronics that provide gain to these low output moving coil cartridges is certainly food for thought. Perhaps a better place to put a head amp is at the base of the turntable itself—where the tonearm mounts to the table. There we can have power and space to make this happen.
What’s stopping us? I suspect if you ask most turntable manufacturers why they don’t include a built-in head amp I’ll bet you’ll get one of two answers: we don’t do electronics or, the more practical of them all, audiophiles don’t want any sort of built-ins.
Separates are, after all, what distinguishes many of us from the crowd.