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Ernie Ball 2721 Cobalt Regular Slinky Electric Strings Reviews

4.0 stars based on 23 customer reviews
Questions about the Ernie Ball 2721 Cobalt Regular Slinky Electric Strings?

Questions about the Ernie Ball 2721 Cobalt Regular Slinky Electric Strings?

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  • Customer
    from MISSISSIPPI April 22, 2017Music Background:
    20+ year pro

    Superb Strings period

    I was reluctant but a friend gave me a set. Ive used the D'addarios for years. Just happened to break a string and his gift set was all I had. Tied`em on and wow. They were full of tone, and slightly louder I suppose. But Tone for days. So, I started using them and have been ever since. I have tried some of the coated strings and they`re just too bright and jangle. These strings are awesome. But I would reluctantly state that these strings are maybe not for beginners nor those who don`t play their guitar regularly, because they are strong. But if you are a daily player you`ll not notice the difference. They also last longer. My normal time frame, when gigging steadily, on a set of strings before using these was about once every week or two, now, I tie on a new set about once every 3-4 weeks.

  • Shawn
    from Poconos pa March 25, 2017

    Best string out there

    I bought these strings to try out on my Les Paul will never buy anything else they sound so nice clear you can hear ever note I'll I have to say is people that don't like them are to cheap to pay the price of the strings or they are playing on guitars that are not set up properly if your guitar is not set up right you will never hear the beauty these strings give these string are for pro's if your a beginner you will think a ten dollar fleamarket amp sounds great Lmao

  • Eric
    from San Francisco January 3, 2017Music Background:
    Years of classical way back when, now just a hobbyist

    Put Some Grrr in your Guitar

    I've been playing Regular Slinkies for a while now on all my electrics, but I just restrung two of them with Cobalt Slinkies. I was literally taken aback. It's like I'd turned up my amp or something. I never thought I'd get this kind of sustain out of a Telecaster…and the Les Paul…. Wow. I'm pretty sure I heard upper partials I didn't know existed coming out of an electric guitar.

    You might actually irritate your drummer, the way these things cut through the mix.

  • Customer
    from fairfield california February 19, 2016


    iv been playing GHS strings for years ,and a friend told me to try these out.i cant believe how good they are! I play metal mostly with high gain amps and these strings really clean up your sound.arpeggios sound totally different you can hear every note better and they seem to be louder as well its pretty crazy iv never been so happy with a pair of strings before.

  • EdKo
    from Niagara Falls NY January 28, 2016Music Background:

    Very Noticeable Difference

    It's amazing the difference these strings actually make. The feel is just awesome. I've been a die hard Daddario guy for 30 plus years and these have made me switch. They need to be tried out to be believed. seriously, its a actual improvement in guitar strings.

  • steven
    from wi August 11, 2015Music Background:
    home recording, hobby

    Ernie Ball cobalt 10-46

    These are awesome strings. Last longer, sound much better, and they have a very smooth silky feel to them. They are pricey but they are worth it. Used D'addario for 25+years and will never go back. Thanks to Andy Plank at Sweetwater for ridiculous fast service!!

  • Amos
    from Washington state April 24, 2015Music Background:
    10 years

    Changed all my strings after one use to this specific one

    Was a fan of the orange diadario till a buddy gave me a set of these. After a few minutes I ordered them for all my guitars. You can play for hours and have no finger wear at all. So smooth to the touch and a great sound too! Stronger than others as well and they stay in time exceptionally well

  • Brendan Steed
    from Ft. Wayne, IN January 27, 2015Music Background:
    Sweetwater Employee, Audio Engineer, Guitar Builder, Guitar Player.

    one killer set of strings

    If you are looking for a straight metal sound or just want more gain without having to twist the knob on your amp or are just looking for a very versatile and playable set of strings that will give you great volume and tone on whatever tone you play on well then these are for you. I strapped these onto my 72 reissued Telecaster thinline and wow what an improvement in overall tone and sound. I now have more gain then I know what to do with and my tone control on my guitar has never been so noticeable. These are an amazing set of strings and I will start putting them on all of my electric guitars.

  • Bryon Weaver
    from United States February 11, 2014Music Background:
    40+ years playin' Blues, Rock, Country, and Jazz.

    VERY COOL!!!

    First of all I've been a regular slinky fan for 40 years! I've tried a few different brands over the years. And the only ones that came close to my ears were the GHS Boomers. But they didn't cut the mustard... That was 20 years ago. And only because our lead player used them. He was wrong!!! Reg Slinky's are the best I've ever used! Until now... These "Cobalts" are better! They hold their intonation even when new!!! And they really do make your axe sound better!!! Point in case... I bought a Gibson "SGJ14" in December and thought it was weak. And stated so in my review. You can read it for yourself! And at the time I meant every word of it!!! I thought the pups sucked! But after a couple weeks, I broke one of the strings Gibson put on it from the factory. So I decided to put the "Cobalts" I bought during the holiday season. What a difference!!! I couldn't believe the tone I was getting just by changing my strings!!! It was truly amazing. I can't wait to replace the strings on my other guitars! Give them a try Mikey, you'll like 'em!

  • mark
    from augusta ga July 5, 2012Music Background:

    Good bye Elixir

    I have played since 1974. I remember back in the 70's when strings broke for me on a regular basis. I read about these in a interview with The ball family in Guitar player and felt "why not?" .. I put them on my 2012 Les paul classic custom since I had some issues with elixirs ( was my favorites) staying in tune on it. it was also a instructional moment for my daughter showing her the right way to string em up.
    Once i was done and tuned up I proceeded to play the hell out of them doing all sorts of bends and such for about 30 mins. My daughter asked me what was wrong. I was blown away. Still in tune. I have never had strings hold tune like that being brand new. I swear never have I been so sold on something. That was 2 weeks ago and have only had to make a few adjustments. Outstanding !!!!!!

  • RJ Kaneao
    from Waikoloa, HI USA June 17, 2012Music Background:
    Artist,musician,producer,recording engineer and Ernie Ball- Music ManArtist

    Ernie Ball Slinky Cobalt (Hawaii)

    I've tried many different strings and wasn't to much a gimmick biter.. Everyone claims to have the best strings and rightfully they should feel that way cause it's their own product.. I have two small string endorsements that I've had for awhile until I got signed by Ernie Ball-music man a month or so ago.. I've used their super slinky for years and lets face it "there's nothing better then a great set of fresh strings on your instruments"! Being that this is my comment and review on these Cobalts I want you to know in no way am I bring partial or bias but giving you a true fact! Ready? Here it comes.. "Ernie Ball Cobalt strings are the best strings I've ever used in my entire life"! I've been a solidified professional full-time musician for 17 years and counting and I'm on stage a minimum of twice a week to 6-7 days a week.. I've literally tried them all or atleast I feel I have.. These strings are a pleasure to use and feel so seductive and light but still holds beautiful tone,sustain is amazing and the output seems to have more gain in it.. Idk what else I could say but this " best strings on the market" hands down! Aloha

  • MA Mealer
    from Tunnel Hill, Ga June 1, 2012Music Background:
    Church Musician

    I was a GHS Boomer guy... until now...

    Best tone out of a string I've had in a long time. They stretch out well and my guitar just seemed to have higher, clearer output. I didn't believe there could be that much of a difference between string brands, but this one blows away all the others by far!

  • Gary Gambill
    from Wausau,Wi March 4, 2012Music Background:
    Music teacher

    thought it was just hype

    I don't buy into the next big thing most of the time,but i thought i would try these strings.I noticed a big difference right away.I bought the 10-46 set but to me they play and feel like a 9 set.for some reason the tension seems lighter more rubbery in a sense.I had my setup the same as far as guitar amps and so on,and there is a volume difference.A person just learning to play might not notice it,but its like there is more of what was there before,if that makes sense.I haven't put down my guitar for about 4 hours now,everything seems to be easier to play.....a bit more smooth....

  • Tim
    from October 11, 2016Music Background:
    40+ years, almost semi professional

    Perfectly fine

    The Cobalt 10s have been my string of choice for the last few years. I can't go overboard; it's not like they turn me into Brent Mason or Jimi Hendrix. But they've got a nice ringing tone and last longer than regular strings, so they are worth the premium, especially at the bulk discount. I mainly use them for blues, rock, and country. And, as everyone else says, Sweetwater's customer service is the best.

  • Corey
    from Washington October 10, 2015Music Background:
    Gigging/recording guitarist, guitar tech, repair, maintenance and restoration

    These are nice

    Ive been using these since they came out. Ive used the 9's and 10's. They are a bit louder, clearer and have more highs than regular Slinkys. From my testing thus far, they seem to retain their tone for longer than standard Slinkys. They do feel different to play, and you may not like that at first but once you get used to it, its no big deal. Many people seem to have a problem with these breaking while they are still very new. I have never had that happen. I make sure my string pressure points at the nut and bridge saddles on fixed or vibrato bridges are smoothed so they have no sharp edges. In fact, Ive never broken and Ernie Ball Guitar string. The only drawback to Cobalts is that they are very bright. On some guitars they are too bright. One of my guitars just didn't work with Cobalts. They were too bright. Generally though, they are very nice, sound clear and full and sound fresh longer than standard strings. I think they are a bit expensive though so I only use them on some of my guitars. Ill keep trying strings of all brands and materials, but Ernie Ball Cobalts are at the top of my list right now. Give them a try. They might not be for everybody but I think they're great.

  • M'Ike
    from Washington April 17, 2015Music Background:
    Live and Recording Musician

    I used them for a couple years

    I put these on a Schecter 006 Elite with stock Duncan Designed pickups. I have used DR MT-10s for about 20-25 years but on my Schecter they sounded a little smeared on the G, B, and high E strings. After reading about the Cobalts in a guitar magazine I decided to pick up a set.

    The positives of these strings are that they are slightly louder and a little brighter than nickel wound strings, such as the DR MT-10s, and have noticeably more definition on the G, B, and high E strings. They stay in tune well and tune right up.

    The downsides are that they have a stiffer feel, are a little more difficult to bend, and due to the hardness of the metal will chew up your picks (plectrums?). Also, instead of losing their liveliness gradually, they kind of hit a wall and lose life very quickly.

    My verdict is that for a guitar with pickups that aren't that great, or on a dark sounding guitar, these will improve your sound, especially if you want some more definition than the standard nickel wound strings provide. If you prefer easy bending and a more predictable loss of string life, I'd suggest not using the cobalts.

  • Greg
    from Asbury Park, NJ April 9, 2017Music Background:
    Guitarist and engineer

    Mixed bag

    I'm a fan of Ernie Ball strings and I think that a lot of the new offerings are excellent. However, I do have a little problem with these Cobalt strings. They sound great and are loud and defined and bend fairly easily. My issue is not with tone or output; it's with the feel under my fingers. I hate the way they feel. They Remind me of the feel of flatwounds. They seem to grab and hold my fingers, making it hard to slide and move up and down the fingerboard, and feel rough and abrasive. I like a smooth string. I want to love these strings because they do sound good, but they just don't feel good to me, and in the end if a string doesn't feel good you're not gonna want to play with it. The new Titanium, on the other hand; those feel great!

  • Donald
    from August 16, 2015Music Background:
    Gigging Musician

    Not worth the extra money

    I've been using Ernie Ball strings for 20+ years. I found these strings stiff compared to the regular slinky strings. I broke a string after 3 hours of live play. I haven't broke a string at a gig in years. In my opinion, while they do sound very good, I can't justify the cost difference.

  • Art
    from CT August 26, 2013Music Background:


    Lots of sound from these.
    But they're hard. Very hard. Compared to regular 10's, I had to adjust the truss rod cause they pull the neck so hard. And unless you have decent calluses, they are hard on the fingers too.

    But they do sound very good - making the twang in a Telecaster even more crisp.

  • Jason Goodwin
    from Wisconsin March 31, 2015Music Background:
    28 year vet

    Not worth it

    I have been playing guitar for 28 years and have always been an Ernie Ball user on all my electric guitars. I usually don't stray from regular Ernie Ball slinky 10s but tried these on a whim. These do nothing to increase volume or output and actually lack that bell-like clarity that regular slinky strings have. To my ears they sounded like dead strings that stay in tune. Overpriced. Hype. I won't buy these again.

  • Shawn
    from Argenta, IL USA July 16, 2012Music Background:
    Audio Engineer, Producer, Singer/Songwriter, Artist, Pro


    I've been a Slinky user for a long time and although these strings sound good, they didn't hold up for my playing. After one gig, they were breaking ( I haven't broke a string in years ). I have acidity hands so I have to wipe the strings clean after every set but it didn't help a bit. I believe I'll go back to the long life coated slinkys as they are more dependable for my playing.

  • Jake
    from August 18, 2015

    Not Impressed

    Upon stringing up my guitar with these (rather expensive) strings, the high E broke within 1 minute of breaking them in. I replaced it with a Regular Slinky .10 and carried on to see if the rest of the strings were any good.

    In a nutshell, they weren't. In standard tuning on a 25" scale guitar (nothing crazy), the unwound strings do feel like they're stretching quite a bit. And after the first one broke for absolutely no reason, I had very little confidence in them to even perform normal string bends.

    The wound strings are unusually and extremely grippy compared to any other strings I've played. I can't see any benefit to this. It makes sliding low notes and chords difficult, which is completely unnecessary.

    These strings do have a notable odd scent to them which kind of put me off at first but isn't technically a drawback.

    The one good thing I can say about the Cobalts is that they do, in fact, sound really good. They are unquestionably clearer-sounding and definitely sound better and stronger than standard Regular Slinky strings. But to me, that doesn't outweigh all the other annoyances of these strings.

  • Abe
    from il July 27, 2013Music Background:
    Recording Engineer- Musician

    Dont Buy These Just a Big Hype

    These strings are just a big hype dont buy these. When I first got these they felt different than the regular Ernie ball strings. They felt really stiff. When I put them on they felt harder to bend than the regular ernie ball. They feel like they are about to break. The tone of these strings is bit brighter than other strings which for my taste is not good and they are not louder than other strings thats just a marketing scam. Just stick to the good old regular Ernie Ball strings they cost much less and they just work

Questions about the Ernie Ball 2721 Cobalt Regular Slinky Electric Strings?

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