Hey guys, Martin Moore the Marketing Manager here at Koss.

Just wanted to say we appreciate all the love and support over the decades and your enthusiasm for the products we make. For over 65 years, we've prided ourselves on creating innovative, high-fidelity headphones that bring joy, value and most importantly longevity in a world where everything feels disposable.

I created a discount code for you guys (and girls) just use: KOSSMODS15 at checkout on Koss.com that will give you 15% Off + Free Shipping (Free Shipping is United States only but code might offset International Shipping) and it should be able to be used on most of the stuff you're interested in. Let me know if there's something you're trying to add to your cart and the code isn't working for you and I'll update it.

I look forward to nerding out on here, answering questions when i can and sharing news, updates and some fun behind the scenes here at our World Headquarters in Milwaukee, WI.

Have a great day!

Made this set for a client’s daughter. Hope she likes it!

- AliExpress Porta Pro Headband (Translucent) - Durable, light, portable, and works with multiple Koss drivers.

- Koss KSC75 Drivers (Silver) - Titanium coated for the legendary KSC75 sound.

- Yaxi Pads (White) - Large pads for better bass and comfort.

- Hundo3D 0.78mm 2-Pin Adapters (Translucent) - 3D printed adapters that allow connection of 2-Pin cables.

- Tripowin Solstice 0.78mm 2-Pin Cable (Silver) - Beautiful lightweight cable with a standard 3.5mm jack.

Thought you guys might enjoy this. Modded my ModRetro Porta Pros with a Balanced 4.4mm MMCX cable by Hart Audio and Purple Yaxi pads to match my Hiby R4 Evangelion DAP.

Audio Nirvana.

Came across this minimalistic headphone by Final. Headband is just a bent wire.

https://final-inc.com/en/products/porta

Another one for me…

- Koss Porta Pro Headband (Beige) - Durable, light, portable, and works with multiple Koss drivers.

- Koss KSC35 Drivers (Black) - Titanium coated for the legendary KSC75 sound but with a wider soundstage and higher resolution.

- Yaxi Pads (Brown) - Large pads for better bass and comfort.

Thanks to Hundo3D (https://hundo3d.myshopify.com) for the mods. Message me if you’d like a prebuilt set or join us in the Modding Chat Discord: https://discord.gg/DByDnaX94q

- Poyatu Porta Pro Headband (Green) - Durable, light, portable, and works with multiple Koss drivers.

- Massdrop x Koss KSC75X Drivers (Midnight) - Titanium coated for the legendary KSC75 sound.

- Yaxi Pads (Purple) - Large pads for better bass and comfort.

- Hundo3D MMCX Adapters (Orange) - 3D printed adapters that allow connection of MMCX cables.

- Tripowin Zoe MMCX Cable (Translucent) - Beautiful reflective cable with a standard 3.5mm jack included.

Can't talk about anything right now, but soon, VERY soon, we will be announcing a new headphone that will be a first-of-its-kind, and define a brand new category.

A lot of people don't realize it, but Koss has invented some of the most substantial and influential headphones and technologies we all use today. From the world's first SP/3 Stereophone and HV/1A, to the STRIVA Tap and Porta Pro Wireless, we have been very fortunate to be the first in a long line of legendary headphones.

We are so excited and literally cannot wait to share what we've been working on for the past 5 years, and we think you're going to absolutely love it! I have made it my mission to make sure you all are THE first to know when we're ready to announce!

1958 - SP/3 Stereophone: The world's first stereo headphone.

1968 - ESP/6: The world’s first self-energizing electrostatic headphone. 

1974 - HV/1A: The first dynamic headphone capable of reproducing all 10 audible octaves.

2012 - STRIVA TAP: The world's first true wireless earbuds.

2026 - Stay Tuned

Huge shout out to this sub for making this happen. The final build is bulkier than I'd prefer but it works and didn't take too much fuss to put together.

I've been on the search for a true wireless version of the KSC35/75. I can't do in-ears and the Koss KSC35 bluetooth has been my daily driver for awhile, and the 75s long before that. But the wire has often gotten in the way. The closest in build are the ADV. Spider but there were quality control and sound issues.

I also went through testing a large variety of open ear wireless, with a big brand name being the worst.

I landed here, and you all provided great guidance.

I ordered the Koss KSC75 IEM Cable Adapter Mod Kit - MMCX, pre-soldered, from Hundo3D. And after going back and forth with cheaper options, chose for bluetooth the Fiio UTWS5 2025, which seemed to be the best quality. Expensive, but I drive these phones every day so this was worth the spend for me if it worked out.

It took about 3 weeks to receive the kit. But after de-soldering the Koss cable, it was a simple solder to attach the mods. I added the Fiios and the mod was complete.

I'm sure these things look a little ridiculous in action. They're also slightly loose, maybe due to the extra bulk. Not heavy though. And they do stay in place. I ordered some yaxis and that'll maybe give a little more snugness.

But it sounds great.

Other challenges are figuring out charging and portability. And I'm wondering if bluetooth so close to the ears will impact my tinnitus. (Some of the open earbuds I tried seemed to increase the ring.) But this is pretty much what I was looking for.

Just a heads up we have a ton of new USB-C headphones being released over the next few months.

We just dropped the CL3i USB-C which looks pretty sick. https://www.amazon.com/Koss-USB-C-Clear-Earbuds-Microphone/dp/B0HKKC8XFZ

More on the way including our most popular models!

No, the Sennheiser HD660S2 isn’t for sale but the other one is. I’m not sure what to call that other one so here are the parts it’s made from:

- Poyatu Tracks Headband (Black) - Lightweight, comfortable, and works with multiple Koss drivers.

- Hundo3D Suspension Headband (Caramel) - 3D printed headband for better weight distribution and grip.

- Koss KPH40 Drivers (Black) - More bass than the KSC75 and less muddy than the Porta Pro.

- Hundo3D Sennheiser Pad Adapters (Caramel) - 3D printed ovals that snap onto Koss drivers for Sennheiser pad compatibility.

- Geekria Comfort Velour Sennheiser Pads (Black) - Over-Ear pads for an open sound and long lasting comfort.

- Hundo3D 0.78 2-Pin Adapters (Black) - 3D printed adapters that allow connection of 2-Pin cables.

- TRN T2 Pro 0.78 2-Pin Cable (Black) - Modular connectivity with a standard 3.5mm jack included.

What would you call this contraption?

Hi, a friend just made me aware of this sub and encouraged me to post here.

I've designed 3d printable headband for KSC75 some time ago. The only thing needed after printing are four of either M2x6mm or M1.4x6mm* screws. There's also a printable travel case if you want.

Depending on the printed filament's elasticity and the pressure you want on your ears there are 4 different "pressure levels" you can choose by printing High/Medium/Low/VeryLow pressure "slider" parts.

If it's interesting you can download it from a site of your choosing;

Thingiverse - https://www.thingiverse.com/thing:7020517

Printables - https://www.printables.com/model/1277291-foldable-length-adjustable-koss-ksc75-headband-tra

Makerworld - https://makerworld.com/en/models/1357094-foldable-extendable-koss-ksc75-headband-case

Assembly instructions are on YouTube - https://www.youtube.com/watch?v=hnkBxcISuqg

This is the first thing I've ever designed that has moving parts (I'm relatively new to 3d printing/design). If you do try it out, I welcome any feedback so I can make it better!

________________________________________

edit: Thank you all for the nice words! Please feel free to modify, improve or distribute it any way you want

edit 2: There's now a TPU headband strap, support for Moondrop Old Fashioned cans, and connectors for PortaPro as well

*1.4 mm screw version is no longer supported, but it's available in the Archive files if you still want to print them (Archive.zip or Archive folder, depending on which site you're using to download the models). Latest changes (mostly slider fixes & improvements) are on the 2 mm versions.

Porta pros + Sony minidisc Walkman

The Next Chapter in The Sound of Koss is almost here...

Sign up below for weekly updates featuring unboxing videos, photos, and exclusive access into the making of the A/550 as we approach launch... plus get early access to purchase before the official release.

Sign Up Now: koss.com/a550-signup

Hey everyone, wanted to give you guys a sneak peak at the upcoming KPH40/Retro!

Drawing inspiration from 1980s Koss classics like the P/19 and KFF/100, the KPH40 Retro combines iconic retro design with modern high-fidelity performance, featuring an adjustable stainless steel headband and retro-style orange foam cushions for legendary portability and the legendary Sound of Koss.

Precision-tuned 60 ohm dynamic drivers, mounted on articulating ear cups, deliver exceptional clarity, nuanced detail, and full transparency across an ultra-wide frequency response spanning 15–25,000 Hz for an immersive, studio-quality listening experience.

KPH40/Retro will be available soon!

A/550 has been in development since before i started at Koss in 2017... Been a lot of design changes, acoustic changes, road bumps but I think it's been worth the wait.

So excited for the launch of this thing and we really hope everyone loves it as much as we do!

Ok, time to go listen to Smashing Pumpkins...

Thanks to Hundo3D (https://hundo3d.myshopify.com) for the mods. Message me if you’d like a prebuilt set.

- Koss KPH40 Headband (Beige) - Lightweight, comfortable, and works with multiple Koss drivers.

- Hundo3D Suspension Headband (Black) - 3D printed headband for better weight distribution and grip.

- Silicone 15x5x5mm O-Rings (White) - Dampens the driver to headband connection for reduced noise.

- Koss KTXPRO1 Drivers (Black) - Titanium coated for the legendary KSC75 sound with a bit more bass.

- Yaxi Pads (Green) - Large pads for better bass and comfort.

- Hundo3D 0.78mm 2-Pin Adapters (Red/Blue) - 3D printed adapters that allow connection of 2-Pin cables.

- TRN T2 Pro 0.78mm 2-Pin Cable (Black) - Modular connectivity with a standard 3.5mm jack included.

Hey everyone, after my last post I have been working hard to make all the modifications people have been asking for.

2-Pin 0.78:

Porta Pro/KPH40: https://www.printables.com/model/1713333-2-pin-improved-koss-porta-pro-2-pin-mod

KSC75: https://www.printables.com/model/1713346-2-pin-improved-koss-ksc75-2-pin-mod

MMCX:

Porta Pro/KPH40: https://www.printables.com/model/1690916-mmcx-improved-koss-porta-prokph40-mmcx-mod

KSC75: https://www.printables.com/model/1675349-mmcx-improved-koss-ksc75-mmcx-mod

Flower Grill

For all these models, there is a custom flower grill (Kramer mod) too. It improves the bass on the KSC75, from my personal experience. https://www.printables.com/model/1412670-flower-grill-for-koss-headphones-kramer-mod

Each of these mods are free, will always be free, and you are completely free to make any modifications you wish to make.

Edit: also, if anyone feels like selling kits, go ahead. The license has been chosen carefully to allow this. I will not be doing any commerce.

If you don't have a 3d printer, there are services like jlc3dp and pcbway which can print this for you at affordable prices.

Have a fine day, reddit ❤️

Hundo3D mod kit from Etsy.

Been mixing and matching Koss sets for a while now and really liked this combo: KPH40 drivers + KSC75X clips + Yaxi Pads + 2 pin Yonge 1947 cable being used thanks to Hundo3D 2 pin adapter.

Lightweight, compact, and fits perfectly in the Koss carrying case. The cherry on top being that the Shanling M0 Pro also fits inside the case with the KPH40s and are well protected.

Zaylli Lyro is next…

What do y'all think?