Orthodynamic Headphones Rating Chart

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Orthodynamic Headphones Rating Chart

This Article will contain subjective ratings of orthodynamic headphones based on the charts in Head-Fi Orthodynamic Roundup thread as well user opinions.

Wualta: 05-15-2009

My opinions, based on the mods we have as of this moment (ie, 2009 but with a few updates) and ranked by the results of those mods that I have heard myself, with exceptions noted. This ranking is fluid. Why? Tomorrow someone will get a bright idea and cure a longstanding peeve. It's happened more than once. A miracle might even occur (someday, someone might be able to get bass and high treble from a Bang & Olufsen U70 without EQ). Case in point: the discovery by the proprietor of this here Wiki that Fostex significantly improved the sound of the once-thought-worthless current production T50RP, which, due to its continuing availability and affordable street price, has gone on to great fame. So don't just read the top few entries and run off waving your mom's credit card at the nearest online auction, and for cryin' out loud, don't ignore the lower-ranked models. Read all the comments. One of the less-highly-touted orthos might be just the one for you.

Some mods are effective but getting them just right is a pain. Some headphones are just physically difficult to work on. These are noted but don't affect the ratings.

It will be noted that this list is heavily biased toward the models that were available in the North American market. Europe was dominated by headphones manufactured by Peerless Mikrofonbau (PMB) and OEM'd for brands like Dual, Goodmans, Grundig, Telefunken and Magnat, but very few of these made it to the US, even today. An exception was the B&O U70 (see below).

Finally, it's worth repeating that with different mods come very different sounds from a single headphone. You can customize many of these 'phones to match your equipment, and of course different equipment will change the sound a headphone makes. It should be kept in mind that lesser phones, once modded, can have more treble and bass extension than even the vaunted T50v1, but won't have its openness and the ease of a certain big-diaphragm je ne sais quois. So hang loose, ortho brothers; none of this is chiseled in stone.

Top Tier:

Fostex T50 (original version, 1978-79, aka T50v1)-- Really stinkin' rare. Keep your eyes peeled but don't hold your breath. Sounds very much like the Stax SR-X Mk 3 but with bass. Not basshead bass, and not the best, tightest bass you ever heard (the little Pro 30 beats it) but clean, pleasing bass. One of the hallmarks of the sound of this phone is emotional, not acoustic: when you wear the T50 you get the feeling of being in a world where everything is wonderfully balanced, where nothing is too much or too little, like good Asian cuisine. The T50 does everything well, though it does nothing better than all others. The response is smooth, extended (but not too much) and flat. Damping is factory-tuned (but because there is damping, headstage is not Lambdalike as you might expect). It's reasonably efficient (for good dynamic range) but not so much that you'll hear residual amp noise.

However, with all the different levels of Hell you'll have to go through to get one, the psychic bottom line looks far better for one of the 2nd tier 'phones, which can be modded to give similar, sometimes superior, but not identical results. Did I say rare? Rare. Fostex never made another headphone like it, and neither did anyone else. Is it the Best Headphone Ever? No, not at all, just a very capable and enjoyable one for the reasons outlined, and a great preview (or tease) of the isodynamic future that never came but which may yet come. Don't step on a friend to obtain one-- it's not worth that.

The T50 (2 versions, 1978-79 and 1980-?) is not to be confused with the different-looking 2002 Fostex T50RP (which also has two versions. See below). The 1980 Fostex T50v2, which looks like the v1 but with a different headband and subtly different cosmetics, is related to the v1 but uses a visibly different diaphragm. Only 1 example is owned by an HF member, and I haven't heard it. Confusingly, Fostex called it simply a T50.

Also confusingly, Fostex OEM'd several versions of the T50v2 using drivers that looked like (but didn't sound like) the T50v1's for NAD, Maior, Lafayette, and possibly others, but using the headband and cosmetics of the T50v2. None of these "clones" can be ranked as high as the T50v1, usually because the treble is weak, but not always (the uber-rare Maior is an exception).

Even more confusingly, there's evidence that some of the clones and variants actually predate the North American market introduction of the T50, leading to the suspicion that what the NA market knows as the T50 was actually a special model designed specifically to emulate the sound of electrostatics of the day. The Stax SR-X Mk 3 was introduced about a year earlier. Coincidence?

Close to top but with reservations:

Yamaha YH-100-- This is a vented-closed 'phone, so it'll never sound exactly like a T50, but it can sound really freakin' good in a variety of ways. Has bass and treble extension beyond that of the T50. Tricky to get exactly precisely obsessively perfectly right, but one of the few old Orthos that needs make no apologies.

Yamaha YH-1000-- Yamaha's flagship TOTL SOTA Orthodynamic. Even more rare than the Fostex T50v1, but you'll hear a lot about it, so it's here. Yamaha put the big earcup attachment/adjustment block right behind a vented-back earcup (a no-no), but yes, the YH-1000 does have a semi-open back, and Yamaha did use some (not much, but some) mechanical damping plus some acoustic absorption in the 1000, the only time they ever did all three on any Orthodynamic. A quick look at the service manual and it's obvious Yamaha was pulling out all the Ortho stops (semi-open back! damping! absorption! aluminum cups! rare earth magnets! copper voice coil!). Nevertheless, it's basically a first-generation Orthodynamic, with a nontensioned pleated diaphragm clamped in the center, just like the HP-1/2/3.

Few people own this phone and fewer have described its sound, but the ones who own it do like it a lot. Sonically, it's dark, obviously a relative of the YH-100, but like the YH-100 it has great potential. The one example I've heard has light damping added by its owner but is still dark, pretty much as the frequency response graph published by Yamaha shows-- a 3dB/octave downward tilt hinged at 1 kHz. This is usual for Orthodynamics, but the YH-1000 seems more linear (fewer bumps and detours in the tilted response curve) than its lesser brothers, which means the diaphragm is well-controlled and the response should flatten out nicely with relatively simple modifications. The linearity means that this headphone will sound pleasing even when its response hasn't been made flat.

Caveats: Two known examples have had corrosion problems on the copper voice coil, requiring painstaking repair involving disassembly of the glued-together driver and the use of a binocular microscope to re-paint the tiny copper traces. Something to keep in mind if one is contemplating spending big money for a YH-1000. Also, despite the metal earcups, the struts that attach the earcups to the headband are plastic, as in the HP-1/2/3 and YH-100. Don't drop this 'phone.

A rare landmark headphone in great demand.

Fostex T20RP (first version, aka T20v2-- another good all-rounder, not rare, usually reasonably priced, and easy to work on. Dull and blah in stock form, though not actively unlistenably bad. Like the YH-100, needs extra-dense damping materials, which may take some time to find. Not to be confused with the later and similar-looking T20RP mk II, which is good only if it has the new-style earpads.

Yamaha YHE-50S-- another very rare one but since it's based on the more common YHD-3 (which I haven't heard, but which should be very similar), and has unique features which can be copied by DIYers, I thought I'd include it. Think of a miniaturized YH-100 with an open(ish) back. That's saying a lot. There's also a mono version, the YHE-50A. Small enough and efficient enough to be used with portable gear. Rated over the TOTL YHD-1 and YHD-2 because it has earcups (backwave control) and earpads (ditto). Note that the YHD-3 lacks the earpads and uses fabric-covered foam slabs instead.

2nd tier:

Yamaha HP/YH-1-- A good place to start your career as an apprentice Orthodynamicist. The low bass of the YH-100 is missing, but everything else is there with the simplest of mods (the socalled Stage One-- a simple felt disc or two placed behind the driver). If you're not a basshead, get one while the online auction prices are still reasonable... sometimes. Not the easiest headphone to work on due to idiosyncratic mechanical design. NOTE: There's an upgraded HP-1 with "keeper" plates on its magnets, giving 2dB greater efficiency. Comes in a black (not silver) box, still labeled "HP-1". Look for the phrase anisotropic ferrite in the specs.

Yamaha HP/YH-2-- Used some cheaper materials than its big brother the HP/YH-1, leading to some problems with crumbling foam in some cases, but sonically very like the HP/YH-1. Just won't play as loud. Comes in a spiffy maroon color. Quality control is a bit looser on this pair of twins, so your YH-2 may not sound like your HP-2. A pain to work on, though as with the HP/YH-1, the results will wash away your tears.

Yamaha YHD-1 and YHD-2-- A work of art that's actually a good working headphone. Powerful, efficient (for an ortho) little drivers with top-tier potential. I badmouthed the YHD-2 for years, but mine turned out to have been atypical-- a nice way of saying busted. Oh,the hazards of judging a headphone from a single sample! The YHD-2 is a slightly less efficient and bassy YHD-1, pretty much as we'd expect. Smooth but dull out of the box, but that's what we want for a good modification outcome-- but there's no room. Downgraded only because these two models lack pads (which could be tweaked to tweak the sound) and cups (which would give backwave control plus room for damping materials). Otherwise they'd be in the 1st tier with the YHE-50S. As compensation, the open design offers some extra headstage. It must be said that many owners love their YHDs as-is. They're so elegant it'd be hard to hate 'em.

Audio-Technica ATH-2 -- Not too common and slightly crippled by a thick, stingily-perforated baffle, it's one of the very few inexpensive isodynamics with an open back. Easy to work on. Driver virtually identical to the one in the Pro 30. To operate at its full potential, the baffle has to be partially cut away, so not an easy mod for perfectionists.

Realistic Pro 30-- Cheap to buy, easy to mod, can give astounding results for effort expended, good (I'm tempted to say killer) bass, compact on the head except for the "antlers". What's not to like? Well, maybe the slightly elevated (but flat) upper midrange and treble. Sentimental favorite, since it was my first wholly successful mod, ca. 1987. The 'phone that should've spread isodynamicry to the masses, and may yet.

Yama HP-3/YH-3-- A bit of a gamble, due to very loose quality control. Some HP/YH-3s are poor-man's YH-100s and some aren't. Not the most common of the Orthodynamics, but not rare (yet). The variant HP-50 series(50, 50A, 50S) were designed to be sold with Yamaha electronic organs. Some claim the HP-50 series uses a unique, superior driver-- all I can say is, mine sounds more like my YH-2 more than my HP-3 or YH-3. HP-50 series 'phones all come with a white paperlike layer over the front of the driver-- intended function yet to be determined. Snap-together construction (no screws), which sometimes leaves backwave-leaking gaps. NOTE: The HP-50A is wired mono and must be recabled for stereo.

Fostex T40(first version, aka T40v1. The box says T40RP but the phone says T40. Dammit, Fostex, make up yer mind.)-- With a very simple mod (detailed in Head-Fi's Orthodynamic Roundup thread) the lack of deep bass is a deficit but not a huge one and bass EQ works well. Very extended and smooth top end, like no other non-stat headphone I've heard. One of the easiest mods (a chunk of foam) gets you there. Same warning as above about confusing this with its Mk II version applies.

3rd tier:

Fostex T50v2 OEMs, aka "T50v2 clones" or "T50 clones" (1980--86?)-- (includes NAD RP18, Maior RPT-50 and Lafayette RP 50)-- For the 1980 model year, Fostex changed the T50's headband from pivoted twin leather-covered-steel bands to a single padded plastic piece, and this is the headband we see on the OEMs labeled Maior, NAD, and Lafayette. Frankly, and to give you a basis for comparison, I like the modded YH-100 far better than the Maior, which suffers because it has an elevated midrange / treble. The NAD, on the other hand, starts dropping after ~2 kHz and keeps dropping-- Bass City. Now, having said that, the clones are T50s in every other respect-- it just sounds like there's a little guy inside with a graphic equalizer who's hellbent on futzing with the sound. Sigh. UPDATE: as noted above, these have what look like T50v1 drivers inside a chassis that looks like the T50v2, but the genuine and exceedingly rare Fostex-branded T50v2 (which Fostex flabbergastingly insisted on labeling simply T50) has a similar driver with a unique diaphragm and which doesn't sound like any of the OEM clones, according to the one owner we know of. Confused yet?

Again, this not to be confused with the much later and very different T50RP, which, I remind you once more, is now being smiled upon by Fostex in the form of life-giving new earpads, making it, in today's online-auction market, 1) affordable 2) available 3)listenable (good, not great) in stock form. Which is so unexpected it's ridiculous. So: if it doesn't have the new earpads (see the T50RP section of this wiki for photos), don't buy it. Or, even better: buy it cheap, and make your own pads.

Fostex T30-- Great potential, but will need a lot of work to get at all of it. Very similar to the T50 inside, but with a less powerful, slightly less open magnet structure and a sound that's tilted basswise very much like the NAD, above. Though the dark sound of the big diaphragm grabs your attention right away and you find yourself listening to it, you won't for long-- the T30 is shockingly uncomfortable to wear. Just about as rare as the T50. Some HFers have devised big circumaural pads for the T30 that make it comfortable.

Sansui SS-100-- Fostex-made, with a big driver that's a cross between the one in the T50v1 and the T30 but slightly closer to the T50. Arguably the prettiest ortho/iso ever made. Sonically similar to the Maior RPT-50 (good, not great; weak bass; not easy to work on), ergonomically clumsy (the earcups don't pivot but float on a rubber subchassis) and therefore a disappointment. Rare again. But some people are just crazy about the SS-100, so what do I know. My impression is based on a sample size = 1.

Fostex T20v1-- Fostex's most famous headphone, used in recording studios worldwide, but definitely not audiophile material without modding, and difficult to get sounding just right. Comfortable, not expensive, easy to work on, but not very efficient and has an upper midrange peak that's hard to tame because it's caused by the conical shape of the baffle (and earpads). Different earpads might cure that.

4th tier:

Interesting 'phones but ones that respond very little to simple modification-- that's why they're here. Most use the 55mm driver made by Peerless Mikrofonbau, PMB, now known as MB Quart. I keep hoping someone will find the killer mod for these. I've been waiting four years.

Peerless PMB 100-- Best of this group. Two versions: Early version used a unique, damped PMB 55mm driver with extra, chamfered holes in a felt-filled chassis, and only HF member JadeEast owns one. Later version, which used a standard PMB 55mm driver in a hollow box chassis with absolutely no acoustic treatment, sounds wonderfully flat, though dry, from about 100 to 150 Hz on up. Below 150 Hz there be hippogryffes but not much bass, which will be found to have fallen off the edge of the map and lost in the shag. Strange Jecklin-design headset that promises much but delivers only a little. Some violently disagree with this, but I don't hear the spatial enhancements promised by the Jecklin open-frame architecture. And to me, the sacrifice of that much bass isn't worth it.

Telefunken TH 700-- Made by PMB in Germany using PMB's big 55mm pinch-type driver. Not much bass or treble.. and it's factory damped! Maybe with a LOTTA work...

B&O U70-- I'm a big industrial design freak, but enough is enough. A work of art first and always, and only secondarily a working headphone. The U70's driver doesn't improve significantly in a more sympathetic chassis. Uses the visually-same PMB driver as the TH 700. Top octave sliced off. Not much bass. It's at least easy to work on since its aluminum-clad plastic body snaps together.

RFT HOK80-2-- Made in East Germany, the old DDR. This phone and the next both use what appears to be the same 44mm East-German-made driver, believe it or not. The HOK has not much bass (very reminiscent of the PMB 100) and is very inefficient but decent mids and top end. Horrible earpads with a lifetime of about 2 years max, but still serviceable even after the seams have split. A very brave attempt considering the political and economic conditions of its birth. Historically significant and shows rare sensitivity to the driver type. Easily convertible to open-back, as if this were a feature planned by the designers. Will accept incredible amount of bass boost and will deliver real bass if you have the amp and EQ for it. Snap-together construction using sometimes brittle materials let some bass backwave leakage occur. Difficult to work on and not for everybody, but hard to ignore. Bass can be improved with dense, low-profile DIY earpads as demonstrated by dedicated HF member DefectiveAudioComponent, also known as DAC.

Goodmans OHP-10-- Well-built PMB-made (West German) headset with the 44mm East German drivers inside. The sound? well.. with flatter earpads and some better baffle seals... As it is, it doesn't sound as flat as the gnarly little HOK80-2! I seem to have the only pair on HF, and that's just as well.

5th tier:

Technics EAH-830-- Very innovative technically but with weak magnets and an uncomfortable, unnecessarily heavy headset and disappointingly blah sound.

RFT HOK80(v1)-- The first version of the HOK80. Interesting, but NO bass and very inefficient. What's there is surprisingly good, but...

Wildcards: I've only heard one of these myself, but they're tantalizing enough to mention them here, and we have some pretty thorough descriptions and mods going on the Big Thread.

Wharfedale Isodynamic(the original 1972 model, aka ID-1)-- I've heard a slightly modified (rear of driver sealed to back of cup) example and except for a big high-Q resonance in the upper bass, it's amazingly good, especially when you consider it was the first isodynamic headphone on the world market and sold for £20 (!!). Very rare in the US, much more common in the UK. Only one HFer owns one in good nick. Not surprisingly, he loves it. A notch filter would be a necessary accessory to live with it long term, but with that the Isodynamic shoots very close to the top. Very inefficient-- works best from speaker amps. Is it a "good-but"? More like a "great-but".

Wharfedale ID-2 / Leak 3000-- one member of the Euro Wing of orthodom does own these twins (which don't sound alike), and he better get busy and put his impressions up here. The drivers look similar to the ones in the Fostex T30 and T50. Not surprising, since Fostex licensed the technology from Rank, who bought up Wharfedale, Leak, and Strathearn.

Amfiton TDS-15 and Echo TDS-16 (early version)-- These tantalizing Russian (Ukraine) 'phones are owned by a couple of Euro HFers. The TDS-15 is approximately a Russian Fostex T50, with bar magnets and a serpentine voice coil but with unique features seen nowhere else. The TDS-16 is more like a YH-1 inside (perforated disc magnets, spiral voice coil) but the driver has clamps like a PMB and a flat, non-pleated diaphragm, not like a PMB. See the Big Thread for the owners' impressions.

Grundig GDHS-223 and 224-- One is a Fostex OEM with a T20v1 driver inside, the other uses an odd driver that we've seen nowhere else but looks a bit like the one in the PMB 100 v1, but with no clamps. One owner of the 224, one owner of the 223. Impressions and ongoing mods on the Big Thread.

Dual DK-720-- Again, one Euro owner, mods ongoing, looks promising. Has some features of the HOK 80 (!) but uses a low-tuned 55mm PMB driver.


This is my fast and basic rating based on what I know and what I heard:

Top Tier:

Audeze LCD-2

HiFiMan HE-500

YH-100 - my fave after modding

Fostex T50RP - after modding

Yamaha YHE-50 - best portable phones I heard when it comes to rock, after SR-001

Tier 1:

YHD-1 - I like this one a lot, the things it gets right they get very right and soundstage is surprisingly good, better then all of my other orthos.

YH-1 - I love these headphones, strangely on some aspects I prefer them to YH-100's that FV had

YH-1000 - not bad but I like YH-100 better, since it gives me a bit of that extra bass and is much cheaper

Fostex T50v1 and v2 - not my cup of tea, but very good technically

Tier 2:

PMB-100 - they have a lot of flaws but what they do well they do very well

YHD-2 - almost like YHD-1

Fostex T50RP v2 - very nice headphones shows a lot of potential

Yamaha HP/YH-3, HP-50/50a/50s - I like these a lot better then Pro 30, even without mods. Go figure.

Fostex T20v2 - very good all around headphones, in my opinion not as good as YH-1, but still excellent for the $


Fostex T30 - I did not like these headphone all that much, dark and very uncomfortable. I never got around modding then and just sold my two pairs in the end. They should potential for modding, but I never realized it.

Tier 3:

Realistic Pro-30

Fostex T20v1

Fostex T10

Fostex T40v1


ATH-2 - I really did not like these, they sounded horrible stock and still very mediocre modded. I am was not willing to play with them as I figures there is not way I can used them as portable. Not worth the $45 I payed for them as I like my Audio-Technica ATH-SJ5 was better and this should tell you a lot as I think Audio-Technica ATH-SJ5 is a very mediocre headphones


Yamaha YH-5M - I want one, don't care how it sounds :)

Goodmans OHP-10

B&0 U70

Russian Orthos


Wharfedale Model

Leak 3000

Kenwood KH-83

--Faust3d 00:50, 12 June 2011 (EDT)

Ericj: 01-12-2008

I can take a whack i guess, and Wualta can correct me.

But this isn't completely fair - for example the Pro 30 is more desirable for it's bass ability and pleasant coloration whereas the T40 is more refined but bass-lean.

I don't know where to put the PMB100, float frames are a different sort of game.

Top Tier:

T50 v1

YH-1000 (we suppose, but don't know)

Close to top:

T50 v2 (including NAD RP18, and Maior RPT-50)

Sansui SS-100

Everything below here requires modding

2nd tier:



3rd tier:


Maybe T20v1 4th tier:

Pro 30

5th tier:





6th tier:


HOK80 (v1)

7th tier:

Current production fostex?


Wharfedale isodynamic



Wharfedale Mk2 / Leak 3000

P.W.B. orthos

Facelvega: 01-12-2008

I'd say the telefunken and PMB100 fall on a level slightly below the YH-100, but are very pleasing with certain music due to the fine, full mids. Here's my version of the ranking, from what I've heard and what you lot have said, including JadeEast below. I've opted for fewer and broader tiers. (question marks for anything not yet heard by at least three of us)

Top Tier:



Tier 1B: moddable, capable of grandness




SS-100, Concept CE-h, PwB dyna-x (?)

Second Tier: excellent but with flaws or requiring modifications


Telefunkens (what was the model number?), aka Burwen PMB (?)

Pro 30

Third Tier: moddable to solid goodness

HP/YH-3, HP-50/50a (? maybe these are upward moddable)


T20v1 (?)

T10 (?)

T40v1 (?)

HOK80-2 (need serious amping)


Other: problematic or not yet enough information

Goodmans OHP-10

B&0 U70


the various Russian models


Wharfedale isos

Leak 3000

Kenwood KH-83

Dual orthos etc.


I will update soon with some kind of personal rankings. But I feel this is a difficult to judge as if a headphone is not stock, the modding could vary by soo much. Also my personal sound tastes seems to be rather different than most (I prefer a warm laid back sound).

iQEM: 09-20-2011

My personal ranking (based on audition em' all) are: 1. Hifiman HE6 silver dragon/Audeze LCD2

2. Hifiman HE-5 LE balanced

3. NAD RP-18/Fostex T50v0/Yamaha HP1000/Wharfedale ID1

4. Sansui SS100/Hifiman HE5/Victor HP D-50

5. Fostex T10/Yamaha YHD3/Yamaha YHD-2/Yamaha YHE-50A/Gundala/Fostex T50RP

6. Yamaha YH100/Fostex T20v2/Fostex T20RP MK-II

7. Yamaha HP1/YH1/Fostex T40v1/Fostex T20v1

8. Yamaha YH-2/Fostex T50RP with v2 pads

9. Realistic Pro30

10. Yamaha HP3/Yamaha YH3/Yamaha HP50A/HP50S on custom housing

11. Eagle H4300

12. ATH1

13. Sansui SS L-55

14. ATH-2/VectorScan VSH5

note: no.1 - 8 & 10 are modded (except ID1), the others are in their stock form...

HE6, HE5 LE & HE5 are recabled...LCD2 using internal cable replacement mod.

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