KH-headphones -- khbaur's DIY headphone journey

Hey all. Bit of an oddball thread here. I will try not to waste too much time, but I figured a bit of a backstory on me would help others understand where I am coming from.

I am another individual on SBAF whose origin story is the Ortho Roundup thread over on Head-Fi. It's where I met a lot of you guys indirectly. If any of you recall, I was always the guy ripping apart ortho's, transplanting the drivers into housings with angled baffles and hand stitching his own earpads.

I believe sometime after I stopped frequenting Head-Fi I built a headphone I was truly proud of. It was made out of a Sony DR-ZX701ip housing and Bang & Olufsen U70 drivers. I loved it. Well ~5 years later I had more disposable income so I decided to make an entire stable of vintage ortho's using this housing as a basis in order to -attempt to- compare them all on completely equal footing. I did not do much research past what I already knew, and of what I knew, any of them could end up on top.

After discovering the YH-100 and transplanting it I was immediately smitten. Their detail. Their crunch / snap... They had a textured midrange with nice slam and sparkle, good soundstaging with nice projected center image. The whole bandwidth was seemingly "forward". It was a good start, but never perfect, often too forward in upper-mids / treble. Then it was a matter of painstakingly tuning them over and over with entirely the wrong earpads and... ears (*ahem* "gear" *ahem*). Trying to figure out channel imbalance and tuning issues I was messing with rear and front damping, getting calluses on my fingers from unscrewing baffles so often. Then I started finding different YH-100 variations from within the production timeline and the plot thickened. I handstitched a pair of earpads which I felt made an appreciable performance increase. Fast forward to me getting ear pads custom made per my specs which add a dollop of warmth making it a much better tuning imho. This process took a few years.

As you may have seen over in @Vtory 's Yamaha Compendium Thread, this is what the headphones generally look like, which Vtory kindly coined as "KH-100's":





Recently I decided to try and trade a pair of KH-100's for another headphone with a SBAF member. He was not interested in the trade, but interested enough to audition my headphones. Well, he liked one of my KH-100 tunings enough to purchase. After selling a couple of my headphones through eBay and receiving good feedback, and after another SBAF member put money where his mouth was and actually bought a pair, I feel somewhat worthy to post this thread.

I realize many vintage orthonauts here are probably thinking, "So what? You transplanted a few drivers...?" I would love for you to hear a pair of my KH-100's and share your honest opinions. I feel there was untapped potential within the Yamaha YH-100 drivers, and I believe these headphones offer a unique perspective on music which is quite satisfying. If the forum would allow me to, I would like to request a formal loaner tour for a pair of my KH-100's. I would greatly appreciate honest feedback to see if I can improve them much more according to the general consensus (tuning direction) as well as increase awareness on the board (or just remind people) as to what vintage ortho's are capable of. If a formal loaner tour is impossible or interest is low, I am still willing to organize my own makeshift loaner program for anyone still interested. Please post here to show interest. I would love to answer any questions, and aside from @Vtory 's outdated impressions surrounding the very first KH-100 I ever produced, another SBAF member has agreed to post his impressions on a much newer KH-100 with way different tuning and my custom earpads. I would love for people to join in and share their experiences with these headphones so we can get a broader sense of their performance / presentation.

Also, if there is anyone out there who wishes to build a KH-100 themselves I am more than willing to share "blueprints", BOM, and as much build specifics / details as is required to build one.

 

I agree that the yh100 has much to offer, glad you kept at it and have something that you feel is consistently good..dB

 

Thanks, man. Yeah, I feel after messing with digital weight scales and Mundorf Angel Hair, or even corriedale wool, the channel imbalances are hard to suss out, ime. I have found that a simple, singular layer of donut shaped wool felt is enough to properly damp and tune and channel balance is typically good as well. Of course, there are still driver variations. Soon I will have four sets of drivers all from different production eras with exactly the same damping scheme, earpads, and housings. I should be able to dissect the small differences in sound between them all. They are all YH-100's and share the same "soul", however some variants are bassier and snappier while others are more organic (presentation and tuning) with better micro-detail and texture. Honestly, it depends on what you're looking for, imho. But I would say that the headphone recipe which I stumbled upon is a really good one and exceedingly easy to follow, therefore as you say, "consistent". Yamaha did all the work on the driver, Sony built a good housing, just a matter of mashing them up. It does not take much to get them to sound extremely listenable, however slapping my custom pads onto these headphones takes them to a new level, ime. If you look at the photo the custom pads which I had made are (completely coincidently) similar in construction to the Yamaha YH-5000se earpads. I believe this particular type of pad has distinct sonic benefits and that it is not "coincidence" that we both stumbled upon this construction completely independently.

 

More thoughts on YH-100 production variations​

So far I've seen:




For reference:

Matte + Copper:
This driver is one of my favorites. Very organic tuning from reduced 6.5-10.5kHz content and also nicely textured. These are bass light / neutral. Great for female vocalists backed by jazzy ensembles and other acoustic. Cut out the dust screens in the pads and they are edging towards Stax Lambda detail, but not quite. They can still get down and rock, however, and they take EQ well.


Matte + Silver:
These were the first pair of YH-100's I ever bought and turned into KH-100's. From this point on the drivers are bassier, mostly all to the same degree within mid-bass region. This variation seems well textured compared to others and they have great sub-bass. Little nasal. Good depth to the image. Great for Rock / Electronic combo.


Brushed Steel + Silver:
Bass is extra punchy from here on out. These don't sound quite as soundstagey as the previous models, little less depth. Little more spice in the 3-5kHz region. Not as organic in tuning as a result. Great for EDM.


Shiny:
Punchy bass. Bit more v-shaped than others. Similar 3-5kHz spiciness. Again, great for EDM. Every KH-100 I have sold was shiny.


Of course they are all great for all music, imho. These are just my, I guess you could say, estimations as to what "EQ preset" captures their spirit.

If you could provide examples of other YH-100 variations I'd be highly interested.

 

YH-100 Mod by KHBAUR330162

Background:

I have been having a great discussion with khbaur330162 regarding these headphones, and have gone back and forth discussing the tuning and driver quality, detail retrieval, and overall sound signature and I am excited to say that I bought a set from him.

The first set I demoed was a bit too spicy in the treble region and a bit pulled back in the male vocal range. I also did not get the same sense of punch/slam that was expected. With some EQ, I was able to bring up the vocals and tune down the treble harshness and brough them to a sound sig that reminded my very much of the HD580, but with better bass extension. We agreed that this tuning was not exactly where I wanted to be, but coincidently, custom pads had just been delivered that might have been a better fit, so I should give this custom mod another go. I was happy to give them another shot since the detail retrieval and overall quality of the sound was apparent. These are a closed back headset that sound open…they are vented, and the imaging and layering abilities are strong to say the least.

On the next round of the loaner, I received two sets that were tuned slightly differently, each with a set of the new custom pads, one with a dust cover and one without, but otherwise the same. The new sets were the dot3 and dot6 tuning updates.

I started with the dot3s and was happy with the way they were sounding, the treble still was a bit spicy, but much better than before, and dynamics had improved. I attribute the better dynamics to the new pad design, or it could be down to amp pairings (more on that later). Switching to the dot6 setup, Immediately I knew that this was the one. The tuning is tilted warmer overall, and the full frequency response in turn became more balanced and natural sounding. I didn’t know it immediately, but I eventually would end up buying this set. The Dot6 tuning addressed the treble and toned it down just enough to present all the information, but not create fatigue, and midrange was now rich in tone. The bass impact also seemed to have increased a good deal, and punchy became a good adjective for their character. Good impact and extension in the low end meant that I stopped bringing out the LCD-2 from its case and ended up selling them off.

I wish I had a way to measure the response, but the description that seems most fitting is that they are natural sounding. Good recordings sound great, with lots of space and detail, while bad recordings still sound good and are enjoyable to listen too. The low-level detail retrieval is impressive, and brings forth all the small background noises that make live recordings so special.

I tried swapping the pads (with and without dust covers) and settled on the set with dust covers because of the extra protection offered. I didn’t really notice a large enough diff. to go without them.


Headphone Comparisons:

At the moment I have a few sets of headphones, only one of them was in stock config for my testing. My lineup for most of the testing were the LCD-2 Pre-fazor, Pre21 LCD-X (fazors removed with caldera pads) and ETA Genesis v2 tuning. I have a set of YH-3s that I should dig out, but I have not included them as a part of this write up.

The YH-100 mod falls somewhere between the LCD-2 and LCD-X in signature. It is tuned warm, has plenty of detail and a good slam. The LCD2 is smoother and presents with a darker tone, while the LCD X is brighter and airier sounding. The KH100 mod is a bit narrower in stage and does not have the same verticality as the LCDs, likely due to the smaller driver size, but for being closed backs they extend beyond the ears nicely.

With the original pair I tested, I had an HD580 to compare directly, and they were very similar in a lot of ways but had more low end. This new version reminds me of a better HD600 or even 650 given that they are on the warmer side of things. I owned a HD600 multiple times and love how natural it sounds, but I would pick up the KH100 mod over it at this point. The mod maintains that natural tonality yet leans towards the Focal Clear type dynamics. The driver is fast and controlled and just plain enjoyable. Hard to believe the driver is 50 years old.


Amp Pairings: Amps are being fed by a Unison Gungnir MB A2 (direct chip outputs)

SW51+ - Not a great pairing. The SW51+ is a bit too neutral and does not provide enough driving power to really wake up these drivers. The overall sound was just a bit too flat.

Cavalli Liquid Carbon – Great pairing. The amp is a good sonic match, but I felt it was underpowered to really make the drivers sing.

DIY Sangaku (nutubes) – Excellent pairing – Powerful and rich the DIY Sangaku with VCAP coupling caps is a fun and one of my favorite amps. The NuTubes fill my tube itch while also being completely non-swappable, curing my nervosa. On the Gaku, this YH-100 mod headphone is dynamic and detailed, but most of all the staging of the instruments is excellent.

Pass Labs Clone Amp – Extra Excellent Pairing – The extra power adds another layer of dynamics and punch to the drivers. This amp has surprised me with its quality over a range of headphones, and having an impedance switch means that it works with a variety. On this headphone, switching the impedance from low to high did not influence the sound in a large way, but it was a change. The switch was used to add a bit of bloom when needed on bad recordings.


Build and Comfort:

Nothing really to complain about on this set. The build is solid, with smooth action in the cup swivel, and firm but easy to change band extension. The weight distribution is even, and though they seem like they could be as heavy as the LCD-X, they don’t feel as big on the head. I have spent many hours with them on my head while wearing glasses. The pads are plush enough, and the leather is supple.


Summary:


The KH-100 mod headphones bring a lot of join to the listening experience and I am glad to have had the chance to try them out.

Thanks KHBAUR for the extended loan and chance to listen to multiple variations.

 

Tysm, @Ksorota for the awesome impressions and comparisons, I feel they touch on all the pertinent points concerning new pads and tuning sound. Also it happens that the tuning you preferred is the easiest to reproduce (has most consistent channel balance). I have tuned Dot1's, Dot3's, and Dot7's the same as your Dot6's and am comparing, they all sound really really great imho. I need to open Dot5's and see how they are damped, I forget what's going on inside of those tbh. I would say the earlier production driver variants prioritize organic, highly micro-detailed sound. The later production variants prioritize slam and midrange crunch. You have a shiny revision driver iirc so it is the latest iteration I have come across assuming I am correct in the timeline. You heard Dot1's first. With the new pads and tuning they are one of my favorite sets now. They have nearly the slam of your Dot6's, but they also have nearly the micro of Dot5's. It's a good marriage of the two sound profiles, imho.

Hopefully we can turn this into an official loaner tour in order for others to add their experiences. I have a project coming up which will allow me to take detailed photos of the KH-100 build process. I will be attempting to make detailed instructions on how to build one of these. I wouldn't assume there's much interest concerning this, but just in case.

 

Registering interest in the build process. Potentially also for a loaner, but it's always a performance getting things across the border.

I'm interested too in @Ksorota 's comments on macrodynamics vs amp pairing. Question regarding dynamics: have you experimented with different damping schemes for different amps with any of these builds? Increasing rear damping does seem to make even these relatively high-impedance planars (and even 50-ohm T50RPs) want more power (or perhaps more specifically current) than I'd have expected just from the sensitivity decrease, and I wonder if there's a correlatable difference between versions.

 

Awesome. I should have build instructions up within a week or two. As for a loaner, yes of course, we can work something out. If I need to curate more private auditions and subsequent impressions before official loaner tour is able to take off so be it. Perhaps you can be another one of the early birds that gets a listen. Shouldn't be too big a deal to ship to BC.

Unsure as to the effects of damping and amp pairing, however, given my experience, I'll wager damping does not affect amp pairings that much. Ime, the cup fillers add a bit of detail, treble hotness and mute the bass a bit, which are things that can be remedied, perhaps, via equipment pairing, but I think the equipment is gonna do what it's gonna do regardless of damping, I look at both separately, but am willing to custom tune any KH-100 for anyone's specific rig. And I think Keith really did pick a good tuning, it's one which presents KH-100's strengths favorably and naturally. I, personally, am pretty okay with bass light presentations and would extensively use parametric EQ settings so I was always listening to other metrics. For most people, I think the new damping scheme and the new custom pads are just what the doctor ordered and should sound good to most ears on most equipment. One thing many listeners of KH-100's will say is how unfatiguing they are. The new pads sweep under the rug the midrange/treble glare I had been attempting to tame for over a year and the new damping scheme is very punchy and fun. I am glad Keith heard what he heard because this pressured me into revisiting that particular tuning with my own ears (was a little too warm for me at first, but I sent them out anyway because I was unsure how they'd be received). It's a good, organic tuning which is easy to implement, has good consistency, and is constructed from in-production materials (at least rn it is), and sounds great with all of the production variations I've come across. @Vtory mentioned an "al dente" damping scheme in his original review. After opening Dot1's they were damped a bit further than al dente, imo. However the new tuning I would consider middle of the road. It's damped, and you can hear the benefits in the tautness of the sound, but the bass is still punchy and dynamic as if it were un-damped almost. I would say it truly is an "al dente" tuning now.

Also, KH-100's love current much like the T50RP (I'd say T50RP's like it a bit more, even, but they are close in this respect), and because of the increased driver distance to the ear they are even less sensitive than you'd expect. The bass on these headphones thrive on speaker amps or anything with unhindered power and can be extremely well defined and layered in the bass given proper amplification ime. I believe these headphones also exacerbate the amplifier's tuning, I feel these headphones glaringly show you the amplifier's character, almost like a caricature of the sound signature. I wouldn't say this is a bad trait to have, however it can be expensive rolling tubes, opamps, interconnects, etc. just to get the most neutral, dynamic response possible. My Nakamichi TA-2A (which was commissioned for Nak by Nelson Pass) into my KH-100's had the most amazing, slammy planar bass I've ever heard. People talk about HE-500's and HE-6's all the time in regards to slam. Well I've only heard the HE-6SE V2 and it's not close. KH-100's are not bass cannons, but they have a moving coil kind of tactility imho.

Someone mentioned in the Ortho Roundup thread that their enjoyment of vintage planars skyrocketed once they got a pre-amp with tone controls. If you are planning on building a KH-100 / tuning it yourself I think this could be beneficial for you as well. It's very hard to get KH-100's perfectly natural sounding without the custom pads ime, and sometimes a 1/4 turn of the treble knob is all it takes to go from "a little shrill with certain songs", to "perfect".

[EDIT]Also, after buying an ECP T3 amplifier I noticed bass was very well textured and nuanced, however, it would fart / distort at max amplitudes with a lot of songs. I finally stumbled on the 12AX7 line of tubes by buying a pair of J&J's. They were really good, the higher gain of the tube meant bass no longer distorted, but I wanted more of the micro, texture and tone of some of the 12AZ7 tubes I had tried. So I bought some vintage Telefunkens that smash any tube I previously heard. Now the bass slam is close to that of my Nakamichi, but also leading edge attack to notes and general sense of micro is well above par ime for a ~$300 headphone. Not only are the drivers fairly well endowed with raw detail, but their particular tuning lends to heightened sense of room acoustics and microphone grains, etc. which I feel adds to the sense of a hyper engaging and realistic recording.[/EDIT]

 

I got the Yamaha HP-1000's much earlier than expected so I had a chance to post build instructions for KH-100's today actually. And for those who may have caught that little spoiler, yes, KH-1000's are in the works. I was super stoked for them, but after hearing HP-1000 drivers I am unsure how these will turn out, bit anemic so far. Of course I will update the thread with impressions and pictures of those, probably tomorrow.

KH-100 Build Instructions
​

First, the hinges tend to squeak. I lubricate them with synthetic oil like so:

​

Here are the stock headphones with pads removed. You can see three points of contact between the driver and the baffle. These all belong to a twist locking mechanism to secure the drivers. This makes it as simple as taking out all the baffle screws and twisting the driver from behind to pop it out (no glue).



You can see two raised lips on the back of the driver adapter. Use these to twist the driver out easily.



You should have an empty baffle like this. Notice the cable strain relief molding. This must be removed in order to make room for a TRS jack.



Like so:



This is stock cable entry point. You can either fill this hole in with epoxy putty and drill a smaller hole to accommodate any hardwired cable you like, or you can purchase these TRS jacks (or others, I'm sure) and they simply drop in, no modification needed.



Like so:



This plastic piece must be ripped out. Grip it firmly with needle nose pliers and just break it off, it breaks cleanly every time ime. Also, it is on the bottom in the left cup and on the top in the right cup. Both must go before we move onto the next step and also in order for the drivers to even fit inside the housings.



Do not install the drivers yet. We need the bare baffles and some Akasa Paxmate now. I typically take both baffles out of their housings and then I press their innards firmly against the white wax paper backing of the Paxmate. This leaves an indentation which I can follow with my scissors to make a perfect housing treatment sheet. See here:




After you cut them out, the one you made with the left baffle goes into the right channel cup and vice versa. Now I place them into the housings and once again press the Paxmate into the plastic to make markings, this time for the screw posts. See here:



Now I take my scissors and merely make a straight cut about a 1/4" past the markings in order to accommodate the screw posts:



Now before you rip the wax paper off there is one more step. AGAIN, press the housing treatment sheet into the corresponding housing and press firmly around the bass port in order to make your measurement mark. See here:



Now stick it onto the housing walls. I tend to aim the bass port hole over the actual bass port and then go from there to make sure it's properly aligned / situated. If you are using the wrap-around wires I find that you can solder the wrap-around wires to the TRS jack and then once you're done stick it under the Paxmate to keep things nice and tidy.



Seal the baffle vents and the hole right above the driver. I use damplifier butyl tape roll for this:



After this has all been completed it is ready for driver installation and soldering. I used to epoxy putty the drivers in place but this made the headphones heavy and was tricky to do neatly. This is a picture of my alternative. I install the drivers via friction. It is a tight fit and will need some coaxing but they do "pop" into the baffles (and honestly they don't even need the glue really, but for the sake of creating a sealed ear chamber we glue all the way around). I use E6000 glue. It is tenacious once it dries (24 hours) however you can actually scrape a bit of it up with a knife and peel it away like stretchy rubber. This ensures you can move the drivers later if you so choose, it is not permanent unless you want it to be.


One thing to note when soldering. The ground pin is the long metal tab coming off the center of the back of the driver. The little solder tab sticking out at the circumference is for your signal wire. I recommend using painter's tape to cover the magnet perforations while soldering to keep rosin from "spitting" onto the diaphragm under the boiling heat of your soldering iron.


After that it's a matter of damping the drivers however you see fit. If anybody wants directions of how to damp KH-100's the same as Keith's pair I can post a link to the felt and disclose the exact methodology, it's not complicated at all.

Also, KH-100's are not the only headphone you can make with this recipe. You can also use other 55mm pinched ortho's, obviously. If HP-1's are more within your budget by all means make a KH-1, they rock also.

If anybody makes their own KH-headphone I would love to hear about it, haha. Please post pics and impressions!

 

Ok, so it has been done. KH-1000's are on my head as I type. Pics or it didn't happen:



How do they sound?

At first I listened to these undamped. They sounded... weird. Hollow. Lacking FR content. I was very disappointed. I decided to try the stock damping which was included with the frankenphone I purchased from Japan. This made everything much more full and detailed. They have bass. They have treble. They have attack in the mids. They are unfatiguing. Male vocals have more grit and grip than KH-100's. They are cleaner and more detailed across the entire bandwidth. Tuning wise I'd say they sound more like a KH-100 than anything. More micro and instrument character, yet certain noises such as individuals in the crowd can sound even quieter and further away than before lending to a sense of space.

-edit- Bit restrained compared to KH-100. KH-100 is more organic and effortless. KH-100 has a lot more slam / punch. Need to mess with rear and front damping I think.



For those interested in the provenance of the drivers, here are photos of the "stock" enclosure.

Yamaha bluetooth headphones. The bluetooth functionality was abhorrent as you can imagine. Via cable they sounded very thin and anemic.


I attempted to seal the baffle vents as well as open screw holes in order to seal the ear chamber. It had a smaller effect than I was hoping for because of something you'll see in the next photo:


There was a thin piece of ?PVC? that was bent around the driver and hot glued to the baffle. So the driver was unsealed all the way around. *Doh!*


Stock damping: