CuNiFe is an alloy comprised of 60% copper, 20% nickel, and 20% iron (the later of which is sometimes mixed with cobalt). It stands out not only because of its magnetic properties, but also because of its unique workability, which allows the material to be threaded into shapes like a screw without being cast or losing its magnetism. Historically, it was used to manufacture speedometers and tachometers for trucks.
But in the 1970s, musical instrument designer Seth Lover had another idea. Lover had been recruited to Fender instruments after having pioneered the humbucking pickup design for Gibson guitars, which helped to eliminate the "60-cycle hum" that was common with a lot of cranked electric instruments. Fender wanted a similar solution, but couldn't directly copy Lover's patent-pending design for Gibson. So Lover began working with CuNiFe wire, and created a new "wide range" pickup, that had a similar effect on the 60-cycle hum, but a completely different sonic character, thanks to the low inductance and weaker magnetism of the alloy, which also required Lover to use more wire coils than was typical on other pickups.
Unfortunately, the automobile industry then began to focus on digital speedometers and tachometers, significantly reducing the demand for CuNiFe (because apparently rare expensive guitar pickups don't have demand to satisfy the alloy manufacturing industry? Who knew?). As a result, the wide range humbucker was discontinued, and left to the stuff of legends.
But now, some 40-odd years later, Fender has finally reintroduced the CuNiFe pickup line. The company has sourced its own CuNiFe manufacturing — even rediscovering the original 40-year old bobbin tool that their supplier had used to create Lover's original wide-range pickups.
Fender apparently put years and tons of money into painstakingly recreating this unique electrical audio phenomenon that was oddly killed off by the car industry. I sat in for a short press conference about the pickups, and it was pretty fascinating hearing how much work they put into the process. Also fascinating to think of the early mechanical invention of this sort of technology, and the germination of an idea to use this random low-iron alloy in order to reduce that mainline hum of A/C current (It should surprise no one who regularly reads this site that I am endlessly entranced by early analog audio technology developments).
Similarly fascinating is the business decision behind this. These pickups are expensive, and their release marks the first time in Fender history that the company is not marketing a new pickup in conjunction with an existing guitar model. That means you can't just go to a store and buy a Telecaster pre-loaded with CuNiFe pickups—you can only buy the pickups, and install them in your own guitar by yourself (or hire someone to do it). The spokespeople at the press conference were surprisingly canny in the way they admitted it was a gamble. But, given its historical importance within the context of the development of electric guitar sounds, it's a gamble that they're clearly hoping will pay off.
As a long-time player of P-90 pickups (another early proto-humbucker, sort of), I'm particularly excited to give these things a shot. Nothing I love more than a highly-dynamic pickup that responds to your playing, with some natural high-end crackle.
