Ernie Ball Primo Slinky Cobalt

I wanted to try the Ernie Ball Primo Slinky Cobalt after hearing so many good things about them. I have to say that the E, A and D strings are excellent: great sound, feel and, most importantly for me, very good tuning stability. In fact, I find them even more stable than the Paradigm strings, which I normally use and really like.

Unfortunately, I was very disappointed by the G, B and high E strings. They are not Cobalt strings and are labelled as “Electric or Acoustic Guitar Strings.” For a premium and well-known product like this, I honestly expected the complete set to use the same type of strings.

In the end, I kept the Cobalt E, A and D strings and replaced the G, B and high E with Ernie Ball Paradigm strings. The result is actually excellent, but obviously this means buying another set as well.

For me, however, this is not really about the extra cost. It is about the product positioning and customer experience. When purchasing a premium product from a brand I know and trust, I expect the complete set to meet the same standard and specifications. Discovering that three of the six strings are essentially a different type of string was a very unpleasant surprise.

I really like Ernie Ball products and have always recommended the brand, which is why this experience was particularly disappointing.

Unfortunately, despite loving the E, A and D Cobalt strings, I don't think I will purchase the Primo Slinky Cobalt again. I will stick with the Paradigm strings or explore other premium brands.

E/A/D strings: genuinely excellent - 5 Stars
Tuning stability: you even prefer them to Paradigm - 5 Stars
G/B/high-E: disappointing because they aren't Cobalt and don't match what you reasonably expected from the product name - 2 Stars
Overall customer experience: you bought a premium set expecting a consistent premium product and ended up having to combine it with another set - 2 Stars