Ernie Ball’s new Cobalt string series was introduced at the NAMM Show this year – coinciding with the company’s 50th anniversary celebrations (which included a huge concert featuring Paul Gilbert, Steve Morse, Albert Lee, Randy Jackson, Joe Bonamassa, Blues Saraceno and Steve Vai – who even donned a Gibson Les Paul for some Zeppelin jammage). The Cobalts are one of two string sets unveiled at NAMM this year, the other being the Everlast acoustic strings, which use a breakthrough nanotreatment to enhance the metal surface so it repels moisture and oils. This treatment is a thousand times thinner than any other coating on the market, and it’s available in 80/20 and Phosphor Bronze alloys, in all popular gauges.

But the Cobalts are really going to excite a lot of electric players. Ernie Ball says its Cobalt Slinky Guitar Strings are engineered to maximise output and clarity and to provide an extended dynamic range with incredible harmonic response, increased low end, and crisp clear highs. Cobalt, a metal not known for its use in strings before now, provides a stronger magnetic relationship between pickups and strings than any other alloy, which you can expect to translate into stronger, fuller tone. Cobalt Slinkys are made with a cobalt-iron blend, and they’re also soft and silky to the touch: take one out of the packet and run it through your fingers and it glides along, with smoother wraps than any non-coated string I’ve ever encountered.

Various gauges are available: Extra Slinky, Super Slinky, Hybrid Slinky, Regular Slinky, Skinny Top/Heavy Bottom, Beefy Slinky, Power Slink and Not Even Slinky. Bass sets are available too in Extra Slinky, Super Slinky, Hybrid Slinky, Regular Slinky, Hower Slinky and Slinky Bass 5 (five string) sets.

I strung up my Fender American Vintage ’62 Stratocaster with a set of Regular Slinky strings (10-46 gauge) and my 80s Fernandes Jazz Bass copy with the 50-105 Regular Slinky set. The first thing to become apparent, even unplugged, was that  that my Strat sounded more muscular, like I’d switched to a heavier string gauge but without the more robust string tension. In fact, the smoothness of the strings made bends feel easier to execute, especially on the wound strings, and I found myself exploring bends in regions of the fretboard that I don’t usually employ that technique in. Once I plugged in to my Marshall, the improvement was very noticeable: the guitar’s output became fuller, taking some of the twang out of the bridge pickup and making it more ‘SRV’ than ‘Hank Marvin.’ It was almost like adding some extra winds to the pickup, or stepping on a subtle clean boost pedal, because the magnetic relationship between the two was enhanced so much by the interaction between the cobalt and the alnico of my pickups. Ditto for the Fernandes bass: the increased fullness to the tone of my DiMarzio Area J pickups was almost like throwing on a compressor or limiter, in terms of how well it lifted the fullness of the tone. On bass, the high end content is very musical while the lows have lots of ‘thud.’

The Cobalt Slinkys do everything that Ernie Ball promises they’ll do: they play smoothly, they sound great, and they work with your pickups to enhance your tone and the interaction between particular crucial elements of your gear. Whether you personally like the way they feel is a matter of individual opinion but you can’t deny the science and the boost in tone.