AKG K240 600 Ohm vs. 55 Ohm
Updated 4/30/19
1,182 word post, approx. 2-3 min. read
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Hey there friend, and Welcome aboard!!
Before we get into the AKG K240 600 Ohm vs. 55 Ohm comparison, grab a snack, sit back and relax because..
You’ve come to the right place!!
If you’re getting into audio but aren’t familiar with Impedance, I’m here to help.
Essentially, a headphones Impedance rating is how much it resists the power fed into it.
It’s that simple.
Learn more: What is Headphone Impedance?
The AKG’s K240 model at 600 Ohm is going to resist power quite a bit.
This is why it’s super important to purchase an amp that will provide enough power into that Impedance rating.
55 Ohm
By contrast, the 55 Ohm AKG K240 will not resist too much, but we still have another dilemma on our hands: The misunderstood and dreaded Sensitivity rating. Related: What is Sensitivity in Headphones?
If you weren’t aware, Sensitivity is basically a measure of how efficient a headphone is.
The higher the number, the more efficient it is. The lower the number, the less efficient it is.
- Anything over 100dB/mW is very efficient, and does not need much power from the amp to reach acceptable listening levels.
- Anything around 97db/mW and lower is not efficient at all, and does need more power from the amp to reach acceptable listening levels.
- 98-99 dB/mW is kind of a grey area in my opinion. If you have a headphone with number like this, take a gander at the Impedance. If it’s a low-ish number as in the case of something like an M40x, you won’t really need an amp.
In the case of the K240, both have an extremely low Sensitivity of 91dB/mW, but with the 600 Ohm, not only does it resist power a lot, but it also requires more from the amp.
A double whammy!
Fortunately for you, I’m here to tell you that there are some fantastic options you can go with to power the 600 Ohm K240 with relative ease. You just have to know what you’re looking for.
JDS Labs Objective 2

Enter the 02, a fantastic entry level desktop solution that has no business being $100. Seriously, this thing is worth way more considering it’s power output, extremely clean signal, build quality, and overall sex factor.
Let’s take a look at the specs:
- Max Output (33 Ohms): 613 mW
- Max Output (150 Ohms): 355 mW
- Max Output (600 Ohms): 88 mW
So, we now know that the Objective 2 will provide 88mW into the 600 Ohm K240 which is probably more than enough.
But..
Before we jump to conclusions and decide it’s worthy, let’s take a look at the Sensitivity again.
91dB/mW.
The HD600’s at 97dB require 20mW to perform optimally. Obviously the K240 is going to require a bit more..
Around 79-80mW.
So we’re in luck! The Objective 2 will power the K240 600 Ohm just fine considering it provides 88.
Fortunately for us, this is the exception and not the rule. Most headphones won’t require nearly that much power. You can see that the folks over at AKG are kind of special. π
Interested in the 02? You should be! JDS Labs Objective 2 Review!
As far as sound?
Sound
The headphones from a sound standpoint are basically identical.
In other words, if you’re a bass head, just don’t even bother. Lol.
But..
If you’re reading this you’re probably NOT a bass head. You likely have more taste than that. You may appreciate the finer things in life..
Stuff like Jazz, Red Wine, Bubble Baths, or even studio reference work. π
The K240’s sound signature is conducive to all of those wonderful things.
Bass
Of course it’s very rolled off. In fact, some call it anemic and that’s not too far from reality.
I’m an ex bass head, but I still like some. Even though the 240 barely provides enough, I still love the sound of the headphone overall because of the:
Mid-Range
It’s absolutely wonderful and makes up for the other minor short comings about this headphone. Instruments and vocals are given ample room to breathe and shine.
Treble
There’s a peak around 9-10k, but it’s not going to sound harsh to you because it’s more in line with the rest of the signature.
Take a look at this graph.
There’s a pleasant quality about this headphone that’s hard to describe. With a good amp, be prepared to be blown away!
The intricacy of the music and the intimate feel that you’ll receive some mind blowing eargasms.
Let’s talk about build..
Build
Build is also roughly the same: It feels like a toy from your local Wal-Mart toy section. No lie.
However..
I had no issues with the build on the K240 Studio that I used, but by and large they are all very lightweight and cheap feeling. There’s no getting around that.
What about comfort?
Comfort
The hammock style adjustment and light weight means these will rest on your head quite nicely, although the ear cups are kind of shallow and the padding is a very cheap feeling faux leather.
Not awesome.
Even with that said, I still think the overall comfort level is above average considering how cheap it all feels.
You won’t have to adjust either too much, so look forward to some semi long listening sessions..
So what’s the final grade?
Final Grade
The K240 overall gets an A- from me.
It’s not a perfect headphone. Build is a bit wonky, bass will be too light and lean for many, and the ear pads are kind of suspect. It feels like they could crack under any type of pressure, kind of like Henry Hill in Goodfellas.
“I wonder about you sometimes Henry.. you may fold under questioning!”
Hehe.
That said, the 55 Ohm Impedance K240 will resist power less than a 600 Ohm. Still, because the Sensitivity of both are the same, you’ll need something like an Objective 2 in order to power them.
Aside from that, the 55 Ohm K240 is no longer manufactured in Austria like the original Sextett 600 Ohm that we’ve been discussing. It’s designed in Austria but manufactured in China.
Some people have taken issue with this but in reality both headphones are about the same build quality wise when it’s all said and done.
Final Word
If you’re looking for the Sextett 600 Ohm, I’d recommend trying out eBay!
If you’re in the market for the 55 Ohm version:
SEE THEM FOR YOURSELF ON AMAZON!!
Well thatβs about it for today my friend! I hope youβve enjoyed this AKG K240 600 Ohm vs. 55 Ohm comparison.
Questions? Comments? Requests? Did I miss the mark on something? Please let me know down below or Contact me!!
Marvin, what do you make of all this? I would love to hear from you. Until next time..
All the best and God bless,
-Stu
Canβt decide which headphones to purchase? Interested in a complete buyers guide outlining over 40 of the best options on the market? Click on over to the best audiophile headphones to learn more!!
Be sure to also check out my Reviews and Resources page for more helpful and informative articles!
Hi! Great review π
I’m an AKG K240 studio 55ohm owner for some time and I love ’em. Which headphone amp would be good with them? I’m looking for a way to get some more punch from them – 2 days ago i’ve connected them to a very old 1970s Philips solid-state amp and the liveliness of drums and bass guitar blew me away.. but the sound was fatiguing my ears after couple of songs. The amp was broken & repaired etc maybe because it’s old the sound is getting distorted i don’t know. So now i’m looking to get that kind of power sound again but without headache π
I’ve been reading some reviews of Schiit Magni vs Topping A30 and here you mentioned another one – JDL Labs O2 but it feels like you recommended it for 600ohm version?
Hey man! I think an Objective 2 or Atom would both be fine with the K240 600 Ohm. To be honest, I got a pretty decent level with the 240 600 Ohm out of a FiiO E10K of all things. Yeah sometimes I think specs are a bit overrated but in no way am I saying that’s the ideal pairing. It just so happens I have an E10K lying around and thought “Why not?” so I tried it and was surprised that it did sound loud enough even despite only pumping 200mW into 32 Ohms. Magni is okay; I used to have a Magni 2 but sold it. It’s not as good as an O2 or Atom. A bit grainier. No experience with the Topping. I would suggest a good DAC + Atom or Objective 2 and you’ll be set for a long time. I would go with Atom because it provides more power and you’ve got a pair of RCA ins and outs as well in case you ever wanted to pair it with some studio monitors. The inputs allow you to use RCA to RCA from another DAC as well, or you could simply use a 3.5 mil interconnect between devices. For instance I paired the Atom with a K3 from FiiO and loved it. Keep me posted!!
Hello there, I own a pair of AKG K240 Austrian made phones. I know that simply plugging them into my Sony 510 processor and trying to listen to my old record albums is not at all the ideal set-up.
I have been looking for a product that will help me to extract the best performance from them. Are you perhaps familiar with any of the products from Schiit Audio?
The JOTUNHEIM in particular is one that I’m considering.
I own their phono preamp called the MANI and I’ve been very satisfied.
Thank you for the article and for the time you put on with these products.
-Eric
Hey man! You’re welcome! I don’t have all that much experience with Schiit products, unfortunately. I used to own a Magni/Modi 2 and ended up selling it once I heard better stuff. That amp was pretty bad when I look back on it. I’ve heard they really improved their product line, so you may have luck with some of the newer stuff. I have an AKG K240M myself! Great headphone. It does need a bit of extra juice. I run it mostly with a K5 Pro. Check out my article on that: Before YOU Buy A K5 Pro, READ THIS!! It has about 1.5W into 32 Ohm. It has a switch with 3 modes. low, middle, and high gain. I’m on the middle gain. I’ve never really needed the third which is one reason I recommend it a lot. It’s just a great product. π Let me know what you think.
I own an AKG 240 600Omh, and until I’ve paired it with a Lake People Phone Amp G3 Ampligor, I haven’t discovered its potential in musical performance.
Now it has a much more powerful and round bass, an equally smooth, detailed treble, and maintains and expands that magic in the middle. Very musical.
Hey man! Love the K240M 600 Ohm. So glad to hear you’re enjoying them! I’ve heard some things about Lake People and I think I reached out to them awhile back about a demo unit but unfortunately did not hear back. I guess it couldn’t hurt to try again!
The only issue with my K240M was that the guy who sold them to me failed to mention the slight buzz at very low volumes which was fairly irritating. I ended up selling them but would love to have another pair in the future. I also owned the K240S for awhile as well. You’re right though; it’s one of the most musical headphones I’ve ever had the pleasure of owning, which is why it’s in my Budget Kings series. if you ever want to take a gander. π Hit me up anytime you’d like to talk audio!
Hi!
First of all, love your reviews, congrats and this is another, is another great one!
You say “With a good amp, be prepared to be blown away!”. I have the K240 MkII and I plan to buy an iFi ZEN DAC. Do you this this would be a good DAC/Amp to the 240’s (and the 702/712 I plan to buy later)?
Thanks and keep up the good work!
Hey man thank you so much! Yeah I think you will be fine with the Zen!! Where are you from?
I’ve been using my 240 Monitor 600 ohms for years. As I’ve gotten more and more into mixing and mastering, I’ve recently tried the Sennheiser 6XXs and Beyerdynamic 990 Pros. Both were so uncomfortable that I sent them right back. The clamping pressure was too much. Yes, I wear glasses and, yes, maybe I’m overly sensitive, and yes, maybe I could have bent them (as I see on Youtube), but I don’t think I should have to do this to get a comfortable headphone. Sadly, I was never able to give them a good workout as a studio headphone. So it’s back to my good ol’ 240 M’s. Bottom line is: get to know your headphones and they’ll work just fine.
Hey Greg! I’m really saddened to hear that about your 6XX! Please give it another chance! LOL. I’ve had my HD600’s since 2016 and couldn’t imagine life without them. They do open up over time, and yeah, the clamp is an issue at first. I happen to really love the snug fit of them because it feels like receiving a warm hug from an old friend, lol.
I do think you bring up a great point though, and that is: people are rarely satisfied with what they have and that’s certainly a huge problem in audio. They’re always looking for the next best thing; their next “fix”, but in reality, diminishing returns kicks in at around the $300-400 mark and there are few products above that threshold that are really worth the price. Yes, the audio improves, but at what cost? At that point, you’re basically mortgaging your life savings for an extra 1-3% increase in sound quality.
If the DT990Pro was clamping too hard, try the consumer version. According to Beyerdynamic, they’re the same headphone, but the consumer one has less clamping.