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Availability:
In Stock.
Arrives
Tuesday, Jun 9
Recently Viewed
Color: Power (55-110)
Style: 4-String
Features
- Cobalt produces a stronger magnetic relationship between pickups and strings than any other alloy previously available
- Patented technology brings a new definition to low end capabilities
- Cobalt Slinkys are also soft and silky to the touch, making string bending a breeze
- Element Shield Packaging prolongs string life and keeps strings as fresh as the day they were made
- Made in California, USA with the freshest and finest materials
Description
Engineered to maximize output and clarity, Ernie Ball Cobalt Slinky Bass Strings are one of the latest innovations in string technology. Seeking to provide guitarists and bassists with a new voice, Cobalt strings provide an extended dynamic range, incredible harmonic response, increased low end, and crisp, clear highs. Cobalt provides a stronger magnetic relationship between pickups and strings than any other alloy previously available. Cobalt Slinkys are also soft and silky to the touch with perfect intonation. Gauges .055, .075, .090, .110. Part number 2731.
Brand: Ernie Ball
String Gauge: .055
Color: Power (55-110)
Instrument: Bass Guitar
String Material Type: Cobalt
Brand Name: Ernie Ball
Instrument: Bass Guitar
Global Trade Identification Number: 14
UPC: 749699127314
Manufacturer Part Number: P02731
Set Name: Power Slinky
Warranty Description: None.
Included Components: Strings only
Item Type Name: Bass Guitar Strings
Model Name: Cobalt Power Slinky Bass
Model Number: P02731
Item Weight: 4.16 ounces
Manufacturer: Ernie Ball Music Man
String Material Type: Cobalt
Body Material Type: Cobalt
Material Type: Cobalt
String Gauge: .055
Color: Power (55-110)
Finish Type: Polished
Recommended Uses For Product: Bass Guitar
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Jun 9
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Color: Hybrid (45-105)
Style: 4-String
These strings ROCK. I bought these in Oct 2023 and still appreciate their sound and clarity on my Z3 Sire. Granted, I did do the water boiling trick a couple of times to get rid of the gunk that accumulates over time but I think thats testament to their overall durability and quality. There are only 2 drawbacks to these in my opinion. 1. They feel a little rougher than some smoother strings I've tried (ex. Daddario NYXL and XT) but this is something you get used to. 2. They tend to rust quite easily. Compared to other strings I've done the boiling hack to, these def rust more. Besides those two nitpicks, they are my favorite due to the output, clarity, tone, and stability. Having tried a decent number of different string types/brands (Rotosound, Elixir, Daddario, DR, etc.) I definitely recommend giving these a try as they are a worthy contender in the gauntlet.
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Reviewed in the United States on January 22, 2025 by Eddie S.
Color: Super (45-100)
Style: 4-String
I've been using Ernie Ball strings for around 8 years and in my opinion these are the best bass strings you can get from Ernie ball. I'm in a rock band called Deadnote (we sound kinda like The Black Crows and Jet, check us out anywhere online) and I've always liked using Super Slinkys, they provide some punch to my sound and offer more tenor timbre that allows articulate playing to stand out better. Compared to other Ernie Ball Super Slinky bass strings, like the regular pack and the coated strings, these provide even more flexibility, texture, tone, and tons of harmonic capabilities. Using these strings I can play harmonics basically anywhere on the bass! I play with a Fender Jazz bass and these strings really bring out the characteristics of the single coil pickups, though keep in mind that they also bring out a little more buzz because of the single coils. I play with finger, pick, and slap technique and these strings work great for all of them. I highly recommend these strings to anybody who needs dynamic strings for many different sounds and with a more treble sound. If you need a more meaty "Motown" sound or something for heavy metal these strings might be too light for you, but Ernie Ball other strings packs like their Hybrid, Regular, and Power Slinkys and one of these would probably work great!
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Reviewed in the United States on November 8, 2013 by Reid W. Clagett
Color: Super 5 (40-125)
Style: 5-String
Great bass strings, fast shipping and sound amazing
Reviewed in the United States on November 4, 2025 by Brona Steele
Color: Super (45-100)
Style: 4-String
I went to buy a replacement set as I had been using EB Cobalts for a while now. I noticed a "used" set posted in original packaging and in good condition, so I thought I could save a few bucks and break-in time. Unfortunately, the "E" was already unraveling and the original buyer returned them and Amazon resold them. Once the outer ribbon starts unraveling they're no good. The original buyer had cut the string, probably before bending it, and it unraveled. Good for the buyer, bad for me. I requested a return and ordered a "new" set. That set came the next day and worked great! Lessons learned, 1) don't buy used strings, 2) bend before cutting or wind the whole string(looks unsightly I know) and 3) buy Amazon as they back their products and mistakes.
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Reviewed in the United States on February 13, 2023 by Miss V
Color: Regular (50-105)
Style: 4-String
I personally LOVE the sound generated by these strings. It sounds dark and gritty, and due to what I suspect is the extra pickup sensitivity, almost seems like it has a built-in reverb effect. Sounds great when writing/covering modern rock and metal music. Doesn't sound too good with most other genres, though, such as jazz or blues. As a metalhead, it's just what I wanted! On the other hand, the strings feel slightly sticky and are a little bit harder to use with fingerstyle and plucking than regular slinky strings. Very slight, but noticeable nonetheless. In terms of sound, if you're seeking a set of strings for modern rock and/or metal, then these are totally worth it. In terms of playability, they are a bit subpar, though workable.
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Reviewed in the United States on May 12, 2020 by Johnny Brzezenski
Color: Hybrid (45-105)
Style: 4-String
Love the cobalt strings. Sounds light and punchy, always clicky on my fretboard at first but lasts SOO much longer then basic strings. Literly cant go back. I did have to re set up my bass after switching, I think there a bit thicker then typical strings and resonate a bit different but totally worth it.
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Reviewed in the United States on April 24, 2026 by Bubonic Chronic
Color: Regular (50-105)
Style: 4-String
These strings sound huge and full and rich. I actually bought them by mistake, thinking they were the Cobalt flatwounds. When they arrived, I thought, What the heck, I'll try them. I'm glad I did. The only negative about them is that, since cobalt is very magnetic, the fingernoise is louder than on regular nickel-wound roundwounds, but in a band setting it's still not noticeable.
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Reviewed in the United States on May 22, 2025 by Jim Glunt
Color: Hybrid (45-105)
Style: 4-String
I have been running Ernie Ball Slinky strings on all of my electric guitars and basses for years. I am more of a bass player then a six stinger so I started putting these Cobalts on my basses soon after they came out. I am not 100% sure that these strings effected the tone of my bass but they do sound great. I would have to do a blind taste test to between these and the steel Slinkys to know for sure. I do remember thinking that they sounded better/fuller with more sustain when I first put them on but thats been awhile and I have basically gotten used to thier sound as my new norm so I dont feel comfortable commenting on thier specific sound charactistics at this point. But I will say this, they feel better on my fingers then anything else I have ever used. I can only discribe the feel as soft and flexable. I love the feel so much that I will probably never even try another string set. I use the Dunlap String conditioner cleaner Jim Dunlop 6582 Dunlop Form 65 String Care on my strings almost every time I play (also a killer product). Having said that the stings seem to hold up for ever. I have never seen or felt any visible corrosion on these strings. I love these strings. Try a set out. I dont think you will be disappointed. They feel great on my fingers. I prefer to buy cheeper strings and change often. For the money these are killer strings.
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Reviewed in the United States on January 22, 2013 by D-Rock