• Non-sound
• Sound
• Comparisons
• Conclusion

Disclaimer: I bought this at my own expense at amazon.se

Price: 20-30 usd (I paid 30 usd)

Specifications:

Frequency response: 15-25,000 Hz

Impedance: 60 ohms

Sensitivity: 101 dB SPL/1mW


Accessories:

None


Cable: A simple cable that is the type that is on most mainstream products. Durability should be fine due to the thickness but the weak point is most likely the connectors on the drivers themselves as they don’t have any strain relief there. It has a diagonal plug at the 3.5mm connector.



Build: The build quality is like a double-edged sword; it is plastic (not very high-quality plastic) but is also very lightweight due to it. Very minimal adjustments can be made in terms of adjusting the angle of the driver. Unfortunately, no L/R markings.

Fit: Very unique fit but no problems for me. Although it doesn’t fit secure enough to be used in physical activities.

Comfort: Extremely comfortable and almost weightless on my ears. Very little heat generation due to the fit (no clamp since it doesn’t have a headband). It shouldn’t be a problem even for hotter countries.

Isolation: Basically, non-existent isolation and it leaks a lot of sound, definitely not something to use in a public place like a library.


Setup: Ibasso DX160 (high gain, volume around 45), stock cable, stock pads

Lows: Very clean bass due to it being very tight/fast but extension and rumble is extremely bad so it is not suited for sub-bass focused genres like EDM, Hip-hop, Trance. Mid-bass on the other hand is better in quantity but is still lacking, but it is very suited for acoustic tracks.

Mid-bass: Metallica – fight fire with fire (01:11-01:52), Very good speed, tightness and texture so it sounds extremely clean and no signs of bloat at all. Quantity is fine for this track but I prefer a bit more so it is more fun. The (02:55-03:01) section is very good and you can hear the chopper very well.

Hiroyuki Sawano – Pretenders (01:18-01:47), Very tight and fast, but is lacking some quantity along with texture to make it fun and to make it more tonally correct (it needs to be warmer).

Sub-bass: Djuro – Drop that bass (01:15-01:30), Extremely bad extension and non-existent rumble. The punch is clean because of its tightness/speed but is also lacking a lot of quantity along with texture.

Will Sparks – Sick like that (03:08-03:22), Very tight and fast but is lacking quantity and texture.

Mids: Extremely high-quality female vocals and very good male vocals. Balancing between male/female vocals is leaning a bit more towards female vocals due to the overall tonality being on the brighter and thinner side. Male vocals are a step behind the female vocals in terms of quality, due to it sounding a bit too bright/thin. But both male/female vocals are very detailed and sounds very clean.

Female-vocals: Hiroyuki Sawano – OldToday (01:25-01:52), Stunningly good, the tonality is very good for this, thin but not too thin and not too bright. Vocals are very clean and detailed. Excellent timbre, just a little bottlenecked in terms of naturality due to the low bass quantity making it lack a bit of warmth for the instruments.

Yuki Hayashi – MightU (01:58-02:55), Extremely natural and tonality is correct.

Evanescence – Bring me to life (01:18-01:35), A bit too bright tonally and a tiny bit shouty.

Hiroyuki Sawano – Crescent (02:07-02:26), Is a bit shouty and too bright tonally.

Male-vocals: Hiroyuki Sawano – Pretenders (00:57-01:17), Needs to be a bit warmer for both his vocals and the instruments, but otherwise very clean and natural.

Hiroyuki Sawano – Scapegoat (00:57-01:17), Lacks some warmth but is very clean and natural.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), Not sharp at but is a bit too bright.

Deuce – America (03:03-03:16), Tonality is too bright.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Tonality on the violins are very good, but texture could be better. Cello´s needs some more warmth but is better textured than the violins.

Hiroyuki Sawano &Z (02:18-02:57), Very natural and clean sounding, but needs a bit more bass quantity.

Soundstage: Huge soundstage in both width/depth but is wider and is very airy.

Tonality: Bright-neutral with excellent timbre. Thinner note weight but not too much so it becomes analytical.

Details: Very impressive amount of details (and yeah, the tuning does have its inherent benefits to the technicalities).

Instrument Separation: No problems at all, very impressive (low bass quantity and very fast/tight certainly helps it a lot).

Music: Fate grand order Babylonia – Hero´s mission, sounds absolute fantastic with its natural timbre and the huge soundstage makes it epic while the technicalities can keep up.

Hiroyuki Sawano – Because we are tiny in this world, extremely natural despite the bass quantity being very low. Somehow sounds fun (with low bass quantity) and yet is very clean and detailed.

Songs that highlight the Headphone: https://www.youtube.com/watch?v=hsXur-NbfG8 https://www.youtube.com/watch?v=3jf_Z68c4LQ https://www.youtube.com/watch?v=vLhafvJvPUI https://www.youtube.com/watch?v=Ek7C5GurYOw https://www.youtube.com/watch?v=gk-mrXzjQo4 https://www.youtube.com/watch?v=8F_11HaH4mE

Good genres: Acoustic music, OST

Bad genres: EDM, Trance, Hip-hop, R&B



Comparisons:

Headphone: Koss Porta Pro, stock cable, stock pads

Bass: Djuro – Drop that bass (01:15-01:30), Better extension and rumbles much more on the Porta. While the 75 has a faster and tighter punch so it is much cleaner, texture is similar on both.

Hiroyuki Sawano – Pretenders (01:18-01:47), Bloated bass on the Porta, while it is very clean on the 75 due to its much faster/tighter bass. Texture is a bit better on the 75.

Metallica – fight fire with fire (01:11-01:52), While speed is somewhat similar, the Porta is extremely bloated due to it being very loose. To the extent that it almost sounds like sub-bass rumble instead of mid-bass punch. Individual bass strikes are meshed together on the Porta while it is extremely clean and detailed on the 75. No contest at all, the Porta is literally dying from blood loss (bass bleed).

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), Tonality is much better on the 75, while it is too warm and dark on the Porta. Much cleaner and detailed on the 75 as well.

Evanescence – Bring me to life (01:18-01:35), Tonality is much better on the 75 and is much cleaner and detailed. The bass on the Porta is affecting the tonality very bad (too warm).

Hiroyuki Sawano – Scapegoat (00:57-01:17), Tonality is more correct on the Porta, but is much cleaner and detailed on the 75.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), Tonality is better on the 75 and is cleaner, more detailed and more natural.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Tonality is a bit better and more textured with the cello´s on the Porta. Violins are much more tonally correct and textured on the 75. Much cleaner, detailed and natural on the 75.

Hiroyuki Sawano &Z (02:18-02:57), Better tonality, detail, cleaner and more natural on the 75.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Soundstage, detail, instrument separation and timbre are on another league on the 75.

Overall: The 75 beats the Porta on pretty much everything except bass quantity. So, for bass focused genre like EDM, Trance, Hip-hop and R&B, the Porta is more suited for those. While the 75 is better on everything else. Although if you want most fatigue-free sound, the Porta is better due to having both lower treble quantity and much more bass quantity.

Earbud: NiceHCK DIY MX500, stock cable, full foams

Bass: Djuro – Drop that bass (01:15-01:30), rumbles and extends a bit more on the MX500. Punch quantity is also a bit higher on it. The 75 is tighter, faster and has a bit more texture.

Hiroyuki Sawano – Pretenders (01:18-01:47), Quantity is similar but is tighter, faster and more textured on the 75.

Metallica – fight fire with fire (01:11-01:52), a bit more quantity on the MX500 but faster and tighter on the 75 while texture is similar.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), Similar tonality but much cleaner and more detailed on the 75.

Evanescence – Bring me to life (01:18-01:35), MX500 is a bit more tonally correct and less shouty.

Hiroyuki Sawano – Scapegoat (00:57-01:17), more tonally correct on the MX500 due to having some more warmth (due to having a bit more bass quantity).

Treble: Linkin Park – Shadow of the Day (03:24-03:42), less fatiguing on the MX500 and also more tonally correct.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Cellos are more textured on the 75 but similar tonality and timbre. Violin timbre is a bit better on the MX500 but has similar tonality and texture. Cleaner and more detailed on the 75.

Hiroyuki Sawano &Z (02:18-02:57), Tonality is better on the MX500 and sounds more natural, while it is more detailed and cleaner on the 75.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Soundstage, detail, instrument separation, imaging and timbre are better on the 75.

Overall: The 75 has better SQ and technicalities but is less versatile due to it having less bass quantity (not that the MX500 would suit bass heavy songs much more than the 75 though…). The 75 is perceived as being brighter overall all due to the bass quantity but treble quantity should be similar.

Headphone: Blon B20, Brainwavz Sheepskin Leather Memory Foam, YY 16 core cable 3.5mm

Bass: Djuro – Drop that bass (01:15-01:30), Extends and rumble much more on the B20. Texture is a bit better on the B20 and has more punch quantity. Tighter and faster on the 75 and is cleaner and more detailed.

Hiroyuki Sawano – Pretenders (01:18-01:47), Similar quantity, but tighter, faster and more textured on the 75.

Metallica – fight fire with fire (01:11-01:52), Faster and tighter on the 75 while texture is similar. Individual bass strikes on the B20 is pretty bad and not very accurate.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), Tonality, details and clarity is better on the 75. But the difference in timbre is very big, the B20 sounds very unnatural.

Evanescence – Bring me to life (01:18-01:35), Tonality is a bit better on the B20 and is less shouty.

Hiroyuki Sawano – Scapegoat (00:57-01:17), Tonality is a bit better on the B20 due to it being warmer, but again the details, clarity and timbre is much better on the 75.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), Tonality is a bit better on the B20 due to it being warmer, but again the details, clarity and timbre is much better on the 75.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Everything is better on the 75….

Hiroyuki Sawano &Z (02:18-02:57), Everything is better on the 75….

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Soundstage is deeper on the B20 while width is similar. Details and instrument separation are better on the 75. Imaging is similar. But the timbre is disgustingly bad on the B20, extremely unnatural.

Overall: DO NOT BUY THE B20! It doesn’t offer anything over the 75 despite the giant price difference and on top of that it also doesn’t have the godly mids that planars should have while it has a very unnatural planar timbre across the entire range.



Conclusion: In conclusion, for acoustic music listeners, the Koss KSC75 is a 5/5. But If you aren’t only listening to acoustic music, then it is a 4.5/5 because the bass quantity is bottlenecking it a lot for other genres. Thanks for reading.

Reference/test songs:

Wanted to share with you all my history with modding these.
 
FIrst, I saw the kramer mod and figured I could do a little bit better. (easier and than drilling a lot of holes)
I decided to fully open this puppy up. 
I went to the dollar store and got a stainless steel sink strainer. This woudl become the new baffle.
I removed the original black plastic baffle from the headphones.
I cut circles of metal sink strainer and epoxied them to the front of the headphone.
Now the speaker had a uniform opening to breath.
 
After doing the above mod, I put the foam ear pads back on. They were quite a bit brighter than I wanted. So that is why the original Kramer mod is the way it is!
 
Next, I bought some knock of sennheiser px 200 ear pads. I figured these move teh speaker a bit away from the ear. Better sound balance and sound stage I thought! I installed these and they were much better balanced and soundstage might be a little better a little deeper. BUT the midrange now has a honk.
 
Time to modify the px200 pads. I realized that the pleather was covering 3 very large side vents on the back of headphones. I cut a bit of the ear pads to unblock these vents and bam. They sound superb now. I would suggest for anyone wanting to mod the pads to perforate the pleather. maybe stabbing it a lot with a needle? micro hole punch? These pads are a lot larger then the stock foam, you will probably need to bend the ear hook to accommodate. 
 
Finally, if after doing the above, they are still too bright for you, you could always install the foam ear pads underneath the px 200 pads. let me know how that goes for you.  
 
Silly Side Note: I admit I am crazy. Before I made these modded Koss, I bought some hd6xx, fostex ebony (stock, zmf and brainwaves hybrid pads) and schiit jotunheim  w/ DAC. I did not like the hd6xx at all with the jotunheim, sold them. I liked the fostex and the effortless bass. The stock ear pads suck because uncomfortable, the hybrids also suck because treble peaks, the zmf pads work nicely. Yet still, I am selling the ebonies and the jotunheim. As of now, I am perfectly content with these Koss and my LG V10. It's just a much more simple setup. I am planning on getting some custom iems to supplement the koss because these things are so ugly I won't go outside with them. For biking and working out I have the se215 on a westone mmcx bluetooth cable. 

 
Costing me only £16, these are one of those bang-for-your-buck kind of items in the audio world.
 
Build Quality, Fit & Comfort
 
The packaging reflects the budget-fi nature by looking like something hanging on a checkout aisle at a Walmart somewhere. The build itself is expectedly not stellar, the cups are made of hollow plastic with holes. The foam is not particularly soft but not particularly rough either. The cable is another issue, being really flimsy and rigid. I would not recommend being too rough with the cable or headphones, as it does feel like it’s prone to fraying – and generally being one caught door handle away from being pulled out of the socket.
 
Because of such build materials, these are extremely light and do not weigh down your ears. They stay in place quite well too thanks to the clips, but don’t expect the wearing experience to be one where the headphones disappear on your head – I’m always aware that they’re on me due to how they sit, balanced on nothing but your ears.
 
Sound
 
The main draw of these headphones is the price-to-performance ratio. The sound is very, very impressive for its price range and form factor. The bass is punchy and has impressive extension for being such a seal-less and light fit. While I can’t say that I preferred EDM with the bass performance, it was certainly stellar for rock and metal music – with kick and double kick drums ringing out clearly in the mix along with the bass guitar, when it came to the low end. I would not characterize the bass as bloomy either, it does not overstay its welcome in more delicate genres of music. However, because the bass is of this nature, and also because there’s no real seal, wearing these in public makes the bass quite anemic – with it becoming a substantially brighter headphone.
 
The midrange is very, very clear and impressive. Listening to Simon and Garfunkel’s The Sound of Silence, the original acoustic version, shows off just how clean vocals can sound on the KSC75. Quite the contrary to the more forwarded mids on some headphones, the midrange of these are actually a little recessed – leading to a remarkably effortless transition from the bass to the midrange, something that I found lacking in both the Sennheiser Urbanite and Beats Solo 2 – which are both headphones that are several times more expensive. However, despite the impressive nature of the Koss in this regard, do not expect a very “natural” or full-bodied sound from the midrange – it actually has an artificial nature to it and a bit of grain. But, for its price, it is the best I have heard yet in open-back on-ear headphones.
 
The treble is probably the most impressive frequency of these headphones to me. I usually prefer a bassier and more mid-forward sound, but I could not deny just how much these headphones breathe. Stringed instruments such as acoustic guitars and violins have so much air around them – with the treble being very well extended without reaching immensely problematic peaks. Due to this extension and the slightly subdued nature of the mids, I would actually say that this headphone is bright overall – despite the punchy bass. However, as with the midrange, the treble is more metallic sounding than natural – but again very satisfying and impressive for its price. I will admit that I do prefer using the Ibasso DX80 digital-audio player, with its slightly warmer and treble-rolled sound signature, with the KSC75 rather than my SABRE DAC based AUNE M1s, which is a bit brighter. I also tried it with my VE RunAbout Plus portable headphone amplifier, but headphones do not really need to be driven as they can sound great out of a smartphone.
 
Another quirk of these headphones is that the soundstage is not very large by any means – which surprised me a bit due to how little they isolate and how punctured and open the cups are. The imaging is largely a miss, with the emphasis of sound reproduction being squarely from the left and right channel instead of projecting in a larger space. Due to this, songs with a lot more layers, tracks and tones can find themselves without enough room to truly shine on the KSC75 – but most songs are not of the nature where it would truly bother a listener using these for what they are intended, which is casual listening.
 
Conclusion
 
Probably the biggest compliment I can give these headphones is that I am critiquing them as if they cost above £100. They go neck to neck with many headphones several times the price on a purely sound quality basis – and even leave some more premium offerings in the dust in the same regard. I personally love when I encounter anything with this price-to-performance ratio in any hobby that I have – not just audio. With that in mind, I can strongly recommend these to anyone reading this review.
 
One final thing though, I did notice that it said on the bottom of the packet that some chemicals used in the construction of these headphones can cause severe health problems, such as cancer, according to the state of California’s regulations. However, I am told that Californian requirements are very strict, and the state has a long list of chemicals that receive this classification – deservedly or not, so make of that as you will.
 
 
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Had these, but sold them when I got a pair of KSC50, which gave me a much more enjoyable and clear sound.
The KSC75 had very little bass impact, cut-off early in the treble, poor detailing in the sound.
Both the KSC75 and KSC50 have a problem with comfort over a longer time of use, the clips make my ears tingle and hurt!
But for a short listening session when I want some "open" sound on a vacation, the KSC50 is usable.
They do provide the bass and detail that the KSC75 does not.

I bought these after reading so many positive reviews and I must say it's disappointment for me.
I tried them on Lenovo X3A40, Xonar ST and Xonar ST + Dispre v4. Many people says they are balanced with nice voals, highs and not so good bass. Well bass is ok for me. Not too much bass like Porta Pro (which I own too). Mids are slightly behind bass and trebles in compare of my AKG 701, Yuin PK1 and PK2, Ety ER6i, Hifiman RE-0. Highs are there for sure. They are sparkling but it sounds soooo rattling. Specially percussions, cymbals. Highs are worst part on these headphones for me and I like trebles. I like lot of trebles, I like sparkling trebles or even agressive trebles are not big problem for me but those from KSC75 are just ... yuck. Wierd thing is they sound good in rock music but are horrible in electronic music or classic music. Vocals sounds like placed into higher frequencies but overall they are nice. Soundstage is not big but separation is OK. I don't like sibilance on KSC75. For so cheap headphones KSC has a lot of details. Also balanced sound is not what I imagine when I'm listening KSC75. Isolation is bad but that's no surprise. Guitars sound nice in KSC75. Porta Pro has more energetic sound, more enjoyable except those bass.
Overall KSC75 are fine headphones but not for me. I like smooth detailed sound like PK1. These sounds more like PK2 with rattling highs, much smaller soundstage but better bottom mids.
I was listening to Faithless, Redhots, Dire straits, Lenka, Die Antwoord, MDK soundtrack, Fatboy slim, Daft punk and something more from Tidal after 12-15 hours burning.
PS: graphs about Audio Quality, Comfort, Design and Value are not like I set so don't look on them.

I am gonna start this where it should. These are the best thing in audio I have found at the price-point. I recently took all the headphones I have access to, and basically did a shootout. For audio quality, these came in third out of about a dozen. The Koss KSC75 came out ahead of the Sennheiser HD558, G4me Zero, G4me One, Monoprice 8323, and some others. Purely objectively, these are crazy for the price. (The two ahead of it were the Philips SHP9500, and the Superlux 668b).
 
The Koss KSC75 are quite comfortable for a clip-on. They weigh about as much as you would expect. The ear-touching thing is not nearly as objectionable as I had guessed it would be. As others have said, switching to a headband style would not be difficult at all. My only complaints with comfort and fit are how the clips dig in a little after a while, and they are a bit odd to center on your ears. This is entirely due to being clip-on.
 
The build quality is low, This is to be expected with anything at this price point, but has to be noted. The plastic backing is cheap, the foam padding is cheap, The cable is comparable to that of an old Walkman charger. The cable is awful. The cable, however, is a good length for portable use, and does terminate in an angled 3.5mm jack, which is good. The ear clips are cheap, and are just plastic. The wire supporting the clips are slightly different sizes on mine. One clip sticks out, and back a bit further than the other. The Koss KSC75 passed the shake the head around, jump, run test as well. These do not fall off my ears, but keep in mind my ears give plenty of surface area to hold on to. Overall, It is what you should expect for the price-point.
 
Now for the sound.
As mentioned before, these beat out some Sennheisers in my audio quality shootout. The sound is inviting enough that fatigue is not much of an issue. The clarity is great. Highs and mids are fairly well balanced with a few peaks and valleys. Vocals are great, but don't stick out so much that it becomes a problem. The bass is entirely dependent on environment and positioning. Overall, I neither find it lacking, nor overwhelming. The is not particularly loose or tight either. Soundstage is good, and the Koss KSC75 passed the CS:GO test with flying colors. These are extremely open. They get the double in the open catagory. Not only are they on ear, they are open backed, and use thin foam pads. The sound signature I would describe as similar to the SHP9500 with a bit more bite.
 
I figure I should start picking a song for each pair of headphones I review to give an idea of what sounds good with them.
Feature song: human - Christina Perri
 
 
Conclusion: The Koss KSC75 are hands down the best (imho) for their pricepoint. The Superlux 668b/ Samson SR850 is objectively better, but is much less inviting, and more cold. Still, I prefer the Sennheiser hd558 sound to any other option I have tried as of writing this. If you are addicted to headphones, or just need something open, cheap, and sound quite good, I highly recommend these.
 
I do all my testing with a FiiO e10, and all kinds of audio files. Please feel free to leave feedback, suggestions, questions, and especially recommendations. All these lower price headphones are a bit of a gateway drug to the world of audio. 

Read the others

 

eargasm

First that all, I called them Pieces of ****, because they look incredibly cheap and ugly, but they sound really good. They remind me a lot to the 668B, both have a fast bass that lacks Sub-bass (On the KSC75 that lack is worse), both have a sort of dry timbre, and both have great highs (Depending on your tastes you might find 668s highs a little bit too bright). To be honest, I find the KSC75 highs a little bit lacking. xD

Soundstage is very good, it is a step back of my 668b's soundstage.

Their clips are comfortable, but It takes a while to put them on. However, you can buy "Parts Express Mini Stereo Lightweight Headphones" on Amazon and use its Headband on KSC75s.
Overall, for 15$ You wont believe how good they sound.

Edit: I´m updating my reviews, I have to add that my KSC75 died (6 month ago) I´ll try buy a pair or even two pairs next year. Also I had the opportunity to try others portable headphones like HD202 and UE4000, and really, the KSC75 destroy the HD202s in almost every way and its on pair with the UE 4000.

UE4000s destroy the KSC75s on timbre and Sub-bass, However soundstage is wider and bass is faster on the KSC75. (I think this comparison is a bit unfair because you can buy almost 3 pair of KSC75 for the price of one UE4000).

Really, even after 6 month without them I cant still believe how good they were, and their biggest problem is how my KSC75 died, the died because their drivers themselves died (Not the outer cable) (It seems that the internal thin wires of the drivers broke up due to knocking).

I was looking for some headphones under $50, went through hell lot of reviews here n got confused about everything. Then somehow the browser showed few auto suggestions n I found these gems.
I read in almost every review that these are the cheapest n best earclips in the market. Well they are best but not that cheap in India especially when the exchange rates are so high. I got them for $25-$26 shipped to India through ebay.
Packaging:- The packaging was good, simple, nothing much to talk about.
Build:- They look flimsy n build quality is questionable. The cable is so thin n so ordinary, I have to be very careful while wearing them.
Comfort:- When I first wore the , I felt they are loose on my ears, so I tried to adjust the clips by slightly bending them. It takes time to adjust them in the beginning but after a while you get used to it.
Sound:-
Bass:- When I first listened to them I found the bass bit muddier. After burning them for 20-25 hours they opened a bit. I would say the bass is soft n punchy at the same time. You cannot listened to them on high volume as they start to rattle. I think these are made for soft listening levels.
Mids:- Some say they are recessed but I don't completely agree to it. Its true that they don't have forward mids but they are not recessed for sure. Mids are very clear, airy n pleasant for my choice.
Treble:- Highs are the most beautiful things on KSC75. Yes they are grainy but in a positive way. They are crisp,clear n I'm loving them. Highs have got nice extension.There is no sibilance whatsoever. In fact after listening to them I started feeling my Soundmagic E30 are bit sibilant too.
Isolation:- KSC75 are open back earpads, so you cant expect isolation from them. They are nice to wear at home or at gym but certainly not for wearing them on the streets if you live in noisy places like Mumbai. I tried wearing them in trains but i was completely disappointed (Don't compare trains in Europe with Mumbai local trains)
Conclusion:- KSC75 are the best deal out there for the price for sure. Sometimes I prefer them over my RE262 just for the love how energetic they sound even at low volume.(RE262 lovers please don't kill me for that, I love my RE262 a lot too, and quality cannot be compared)But it's just the characteristic of KSC75 that you fall in love with them. They look funny on the street. I look like a character from 1970's science fiction film. But I don't care about it as long as I'm enjoying the sound of it. As almost everyone said earlier, they are must have headphones and everyone should own these at least once in your life.
 

 
 
My simple tiny set-up-Cowon C2 + Fiio E6 + Koss KSC75:-

I bought these KSC75 clips because I lost my modded Koss UR55 and I read oodles of praise for them online. At first I was skeptical because they are very flimsy looking and they are often compared to the Koss PortaPro which sounds muddy in my opinion. So I tried them on and I was immediately impressed by the overall balance and airy sound. Everything sounds so natural and forward, and it's really easy to separate vocals and instruments. I really like these with pop and rock music. The KSC75 crush the PortaPro. However, I must say that the treble feels grainy at times, especially with shimmering electric guitars (typical in post-rock). Another complaint would be that they look super dorky on your head, especially next to the PortaPro which is very stylish. 
 
I think that the KSC75 would almost better the Grado Sr60i, if it weren't for that grainy treble. They are that good. 

They have good old fun sound signature, very engaging and very dynamic. I found mids are a bit too recessed for my tastes and affected by the low region unfortunately however from a cheap can like this, I don't expect the separation of HD800 obviously. Treble is nice, sparkling very detailed and crisp. Bass could be more controlled but it does its job, it has a strong, punchy bass and when the song calls for it, it knows how to give 'boom' effect.
 
So what do we have here? Very good sounding on ear headphones which can easily compete against 100 euro price range. Is there a problem, you bet! Some people seem to like the design and clip system but I totally hated it. I am currently looking for a chance to make a headband mod otherwise it is too painful for me to wear it longer than 20 minutes. Also I keep on playing with the clip because it doesn't fit correctly and keeps on moving around. Design-wise, unfortunately they are failed in my experience.
 
At this point, you probably know that they are open back cans, so they don't isolate and they leak sound quite a lot. If you want to hear your surroundings, that's good for you but pay attention, you might disturb people around you.
 
They are also easy to mod, I saw already Kramer mod and headband mod. If I can do the headband mod (looking for a headband donor cheapo headphone) I will continue with the Kramer mod too.
 
Also, they might need a little bit more power than your usual average consumer targeted iems/headphones.
 
I have problems with comfort but I like the sound, I will try to mod them to keep it, otherwise no go for me. I bought these ones to use in gym not as a main headphone and for 15 euros, I think they punch way above their price. However, if I fail modding, probably I am gonna order PX100-II to use at gym.
 
So if you are looking for can to use in the gym or outside running they are good. Also if your budget is tight, I can still recommend them since they are kind of giant killers. Just be sure that you can handle the clip system or do a headband mod.

....... as a young lad, some 30 years ago, when I first got into headphones and placed my order from J&R music world, waited in ernest for that UPS truck to deliver my pro4AA 'digital ready' headphones. I'd just gotten my new technics CD player and copys of police-ghost in the machine, billy idol's rebel yell and dark side of the moon. before cd's all we had to listen to for portable music was via tdk and maxell tape through a sony walkman that were dubbed and traded from friends lp collections. There was only a few cd offerings at first and boy was I excited about the dynamic range of the digital sound and really liked the idea of instantly skipping to my favorite song and lack of cracks and pops that were the norm on my turntable.......but I digress, the Koss sound was a good one even back then, but the ksc75 reminds me of what I like about vinyl whereas the digital ready pro4aa was a less organic sound. The ksc75 is an accurate and natural sound with the exception of the top end which is inaccurate and is thrashy. Cymbals will not sound right for example. This may help with some amplification but who buys $20 headphones to use with $400 amps? In any case, I've not found amps to completely solve the high end problem......while these headphones have a nice analog'y sound, there's nothing here that will astound or impress for anyone 'into headphones', unless you really just like to sit down and listen to your favorite music and are on a budget. Eq the treble down a notch and enjoy....... 

If there are better sounding headphones in this bracket, they sure aren't available to the public yet! The KSC75s just might represent the apex before the downslope of diminishing returns.
 
The sound: Very fun and engaging all-purpose sound. The bass is certainly present, although far from basshead territory, the mids are maybe a little recessed, but they sound just great all the same, and the treble extends nicely without a trace of sibilance or harshness. 
 
Design: Probably the only downside to these guys. The driver covers look super-cheap and the earclips make these the most uncomfortable cans I've ever used. Granted they do get more comfortable as they loosen up. I however, would recommend to anyone who experiences discomfort (which will most likely be anyone with ears) buying a  partsexpress headband to use with the 75s. Super easy to install and totally relieves all of the discomfort.
 
Value: Like I even need to go here. For under $20 you can purchase earphones that rival in sound quality, IEMs and on-ears in the $75-$150 range. When's the last time you saw a frequency response of 15-25k Hz for phones that cost less than $100 brand new!? Such a great deal! At the very least everybody should try these just once. I was able to pick up mine for $5 a pair as they were recently put on clearance at a local office supply store! Two pairs of $100 sound earphones for $11 including tax.
 
It should  be mentioned that the 75s don't come with any accessories like 1/4" adapter or case, but honestly if you need a case, you can find something cheap.
 
If you need some beaters that are gym-ready, office-ready, or just walk-around ready, look no further. Plus they won't break the bank! Kudos to Koss!

I bought these this week from amazon.co.uk for £10 including delivery. That's US $15.

edit: I've changed my rating and feel more positive about these than when I first wrote the review. See the comments after the review.

Packaging, appearance, warranty, euro-nanny knows best:

Mine arrived in the small European packaging box, branded as Pulse clips as well as "Koss high performance on-ear clips". With the clips came the Koss warranty and the euro-nanny-state leaflet on waste disposal. The phones are the silver plastic Koss branded items everyone knows.

The lifetime warranty is valid but irrelevant because shipping costs from UK will exceed the value of the product. But I do very much appreciate a company that has faith in its products and is known to honour the warranty.


Construction, design, materials, euro-nanny isn't done yet:

The slightly odd design works extremely well. With a little careful bending of the plastic-enclosed metal clips I got a good snug fit and no discomfort. I wear spectacles with ultra thin titanium frames and there is no difficulty. With more conventional specs there could be obvious problems.

The silver plastic parts are a blast from the past, looking like cheap stuff I remember from the 1980s. But I don't care. The materials clearly do the job and don't cost much. The cable is unremarkable, 4' long with a straight jack. When I go to plug it in I notice a tiny sticker attached: it's another euro-nanny warning not to dispose of electrical items in household waste. Yes mummy. No mummy. There is a committee in Belgium worried that the first thing a customer will do is cut off the non-detachable cable and throw it in a landfill. I won't do that because I like to listen to some tunes while burning old tires and drunkenly shooting at endangered species in the national park at 2 am.

Everything seems properly assembled and when I press play it works as intended.


Using with portable players:

The Koss KSC75 need much more power than typical budget portable headphones, IEMs or buds. With a player like the Sansa Clip+ you'll probably need to run it at or close to maximum volume which means battery life is reduced. This is especially true for well produced music such as from before the modern loudness war fashion, and any classical music. My iRiver H140 and H340 players put out about a third more voltage than the Clip+ and do a much better job of driving these Koss earphones but unless you're in a quiet environment it might both be not enough and also too much because.....

Isolation:

There isn't any in either direction. If you use these on public transport everyone will hate you. In the street or a noisy workplace you'll hear everything around you and anyone close by will hear your music. The natural thing to do can be to keep raising the volume. This is the road to hearing damage. Compared to using IEMs I find myself running the Koss 'phones at dangerously higher levels and still finding the background noise doesn't let me fully enjoy the music. Beware.

Sound Quality:

It has some bass, which is a welcome contrast to similarly cheap buds and IEMs. I've listened to some orchestral music, some harpsichord pieces, some choral music, some heavy rock and some bass heavy electronic stuff. The sound is nicely balanced and generally enjoyable. The biggest defect is poor stereo imaging. There is no possibility of imagining oneself being present at the performance. There is no convincing illusion such as I get with a really nice recording and my Shure SE215 or Sennheiser CX 95. With the Koss 'phones the impression of sound is close left, close right and a slightly recessed bit in the middle. Some of this is due to the lack of isolation. For the last few years I've been using IEMs and closed and semi-open headphones. I am really surprised how background noise such as the rumble of traffic from the street below or a kitchen or bathroom extractor fan might not be loud enough to dominate the music but is enough to really kill the dynamics and imaging in a fully open 'phone.

The above might sound overly critical but I'm trying to describe the experience without allowing the price and value to totally colour my opinion. It's true that the Koss KSC75 is still unambiguously better than any bud or IEM included with any device I've ever bought.

Is it worth £10?

Yes, but I might not have bothered if it had been £15 and I definitely wouldn't pay £20 because for £30 I can buy Sennheiser PX 100-II that have much nicer sound, work better with low powered portable devices, are made of nicer materials and come with a carrying pouch. I would also hesitate to recommend these to anyone because the tendency to keep raising the volume to dangerous levels is hard to avoid. Because you can get a better sounding headphone at £30, and better sounding IEMs at less than that, the Koss is running out of selling points and has too many drawbacks. The most attractive feature is probably the clip-on design which is great for runners and people working out and those who won't or can't use IEMs.

It's about 9 pm here, the traffic noise has died down and I'm starting to enjoy the sound much more. And that's why these are hard to recommend as portable 'phones: they only make sense in quiet environments where others won't be disturbed. I expect to mostly use them with my PC because the USB soundcard has enough power to drive them properly and it's good to still be able to hear voices, phones, the doorbell and so on. These are also good to use with a mini system or domestic portable.

Conclusion:

As odd as they look. An idea whose time has come and gone. Worth £10 or £15 but not giant killers any more.

Taking price into account above all else, these are the best headphones I have ever owned.  Obviously my HD650s and DT880s sound better, but they also cost 15-25x as much. I've probably put ~150 hours on them. I did do the kramer mod (involves drilling a few holes in the driver cover to allow more sound through) but they sound great even without the mod. I also bought a Parts-Express headphone from Amazon, took the garbage drivers off them and snapped the Koss drivers on. I find them much more comfortable this way. As a plus you can bend the headband however you like to suit your comfort level. Some people do the "quarter mod" where you put a quarter over the earpads (after taking them off the drivers) and cut out a circle to allow more sound through as well. I chose not to do this because I love their sound with the kramer and headband mod.
 
I listen mainly to electronic music, so people who listen to more jazz or rock might not like these as much as I do. But for trance, dance, dubstep, these are simply amazing. My DT880s show me new things in my music that I've never heard before. It's one of the things I love most about them. Now this isn't me blowing smoke... but there have been times I heard something on the Koss that I've never heard before. This includes faint vocal tracks in the background, synths, and little things here and there.
 
These are my work headphones, because they allow me to hear people talking and not completely isolate me from my environment. Some people say they leak too much sound to use in public, but I use them in my cube and no one has ever complained about hearing my music. I don't crank them up but I certainly don't listen quietly. I use them straight from my phone (Nexus 4) and they sound great. I brought my Fiio E17 to work once to try them amped and I just felt like they lost some of their magic. Don't ask me why, or how, I don't know. All I know is that they didn't have as much sparkle, which is something I love about them.
 
I'm no expert in describing audio, but I'll do my best. They have a great attack and decay on the notes, which to me translates to good PRaT (pace, rhythm and timing). The space between notes is very discernible and they just get me groovin'! The imaging is fantastic as well. I can clearly hear music going from side to side, and even in front of and behind me to a degree. The bass is punchy and extended. It also has a great texture to it. It's not muddy or bloated at all. They're also very airy and have a nice open sound to them. The treble is sparkly but unfatiguing (in my opinion). Some people find them a bit too treble-forward, but I have experienced almost no sibilance from them. Mids and vocals are good, nothing amazing but they're not recessed. Female vocals are quite nice on them, with male vocals almost as good.
 
I honestly think these are worth $75. I might be slightly more critical of them at that price, but these are so cheap, I have literally nothing to complain about. I don't plan on recabling them because I love them just the way they are. I bought 3 pairs over the holidays to give to friends. I only ended up giving away 1 pair. These are just... so good. I'm more satisfied with these than I am with my HD650s.
 
What Koss has done here is simply magical. I would never have dreamed something so good would be so cheap. I honestly could not love these more. They are my favorite headphones out of all that I have ever owned.
 
Thank you, Koss. THANK YOU!!!

This are Titanium coated Earphones. Actually I've known no other headphones brand that uses this kind of technology. 
Pros: Excelent Sound from the very bottom low frequencies (well balanced and undistorted), through excelent mids definition, plus a superb high definition (no like other phones which sound like piezo electric cheap tweeters on your ears!).
Once you get to know how to wear the clips, you forget that you have the KSC75 on.
Cons: The volume control is oversized and after let's say the first 4 months of wearing, they sound like my grandma's Telefunken hi-fi audio system knobs!!!  
The clips get unuseful very quickly (due to the wear iself) too. So you may have to use a little superglue dots in the clip/driver-junction to make them a little tight again.
 
I´ve used Koss stereophones since I first knew the brand using a set of Koss' TNT (Titanium Nitride Tech) 66's, which lasted me more than 18 years of really serious home-studio use!!! The sound never changed.!!! (I only had to change the cable twice during these years).
Well this little set of portables (KSC75), are amazing with no distortion perceptible at loud or mid volumes, also you can hear the fingers stepping over guitars when listening to Acustic Alchemy with no fatigue, or you can actually feel the solid bass in some late remixes by Tiesto and Armin V.B!!. This phones can handle whatsoever kind of music. Even let me tell you that once, when I had to suddenly move to another state for a while, I  didn´t have the budget to get a koss or a Bose set of new phones, so I went to Radio Shack and bought this model KSC75 and opened them, and together with another set of Audio Technica phones (not inexpensive at all, by the way) that I already had; So I took the audio technica poor sound quality drivers away and then i glued these KSC75's (takin its clips only off) drivers to attach them to the Audio Technica's right and left shells, and... Voualá!!!  I got a new set of pro-stereophones!!  I compared their sound to one friend of mine's BOSE AE2, and believe me, the only difference was the more powerfull bass on this Bose's. But in mids and high tones, I prefered the koss natural balanced sounding.. Anyway Paying more than 150 bucks is worth the KSC75!!! 
 
So i love them very much for the quality of details you can get from any kind of music, and there is no comparison against Skull Candy, Sony, Pioneer, even some Panasonic or JVC bass powered models... Obviously, talking into account products under the $100-$150 price!!
I have to mention by the way, that these clip-ons are open-design, so when you give them a better acustic environment, you´ll exponentiate their bass response through your ears too.
 
And if you evre don´t have the budget for a BOSE or any higher koss model, think on having these 75's and put them into another stereophone shell just as I did, and get amazing bass response with new acustic!!!
 
So give them a try and find why this inexpensive model is an outstanding performer out.  It's around $15-$20 bucks only!!!
 
Hopping this helped you to decide with your next shopping!!! (dec.2012)

As someone who enjoys all different kinds of headphones and has owned a few different ones at a number of pricepoints, I can reccommend only one headphone to pretty much anyone who listens to music and wants more fun out of their portable rig. That phone is the Koss KSC75.
 
Why are these phones so great, so much so that I am on my fourth pair? For half the price of an apple earbud, you get a pair of detailed, easy-to-drive, energetic and involving headphones that will bring out detail and life you have never experienced with the phones that came with your ipod/iphone/walkman/discman/minidisc player etc. While they are not perfect, They are so good that I use them more than any other phone I own (including ones that cost 100 times more) that I can only assume that it is my favourite headphone of all time.
 
Looks aren't that great, let's be honest. You aren't going to impress your Dr. Dre Beats-wearing friends with these, and the clips take a while to loosen up to where they dont pich your ears. And don't expect world-class build quality either -- the plug and cable is flimsy and is prone to breaking easily. It helps to be handy with the soldering iron if you want em to last longer than the gestation period of your average foetus. But that's not the point of these beauties. It's their incredible sound quality for the price means you can buy three or four pairs and always have a spare ready in case one needs repair or needs to be tossed.
 
In terms of genres, I find they do best with genres that aren't so dense and layered. Metal and heavy rock can get a bit muddled and muddy, but it's still a marked improvement over most earbuds. Jazz, folk, country and blues go fantastically well with the Kosses, and electronica sounds great (but a little light on boom in the bass area if that's your thing). Hip hop is not my area but the stuff I have is serviceable but not outstanding.  I should mention that they don't isolate sound at all, which is both a positive and a negative. For me, it means I can use them while riding my bicycle at low volumes and still hear quite a lot of what is going on around me. For that reason they are the only phones I use on the bike or when running. Not that I necessarily endorse using headphones on a bicycle, though I have done it extensively for many years and am still here to tell the tale. So there's that. Of course the negative to this is that they leak sound like crazy, so you have to have them pretty low not to annoy people on the train or in the office. This is their mean weakness in being a portable phone, so if you listen a lot to music in public, you might need to look elsewhere.
 
They respond well to amping, I use a Ray Samuels Hornet portable headphone amplifier with them and they do gain a bit in bass control and punch, but the beauty of these phones is that you can drive them perfectly out of your iphone or ipod headphone jack. They give great detail but they're not so good that they make your 128kbps rips sound like crud, which is a big issue with the better phones. And their all-plastic construction means they're light and very portable.
 
I love these things and I hope they never go out of production. They can be modified and repaired easily, are cheap as hell and worth at least five times their asking price sound-wise (but not construction wise). Try a pair today, you really have nothing to lose, and I guarantee you'll like them a lot more than your apple ibuds. You might even like them more than your $1000 Beyers or Sennheisers

If you don't own a pair, BUY THEM! Seriously, their that good.
I prefer them to my DT990's, hands down. Nuff Said.
 
If that still doesn't convince you, they're super comfortable once you adjust them properly, sound fantastic, cost $20, and can be modded for fun.
 
The ear clips are pretty durable. I've snapped them off the drivers multiple times to adjust the clips and the connection point is still in perfect condition without any stress marks that usually happen in plastic.
 
I might have limited experience, but I can't imagine a higher value.  

These headphones have it all for the price. I've never heard anything like them at this level. They have a clear, balanced sound with all frequency ranges represented fairly equally, with mids and highs ever so slightly forward compared to bass in "clip-on configuration". If you mod them with a PortaPro or Parts Express headband, the drivers are pushed closer to your ear and give a bit more bass and mids.
 
The main thing that stands out with these is a simply silly amount of instrument separation. Everything sounds like it is popping out of a pure-black background -- think of turning the contrast up on your TV or monitor; or more correctly, adjusting the gamma level. This lets you analyze tracks very easily, useful if you're a musician. A downside to this is that they don't sound too "cohesive", and music can sound a little hollow, flat, or broken-up. Don't confuse this in any way with "dull", though, because they are full of energy and never fade into the background, while still not being harsh.
 
A fairly unique sound in absolute terms, and a steal at the price. The only downside is the comfort of the clips; I could never get them to feel great, but they were at least functional. Good work Koss.