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Orthodynamic Roundup - Page 3

post #31 of 23459

Yamaha clone

Greetings!
For quite a few years, I was wondering the phones on the attached pictures were a clone or the original design - until recently I came across phones featured in this thread. Well, as you see, they do have a striking resemblance to the Yamaha!
I bought two pairs of those Soviet-made 'phones new in the early '80s; they were called "isodynamic" and back then were likely the best ones produced over there and were most expensive. The sound quality was quite good (or appeared so) back then, but deteriorated over the years. Last year the first pair has developed destortions, and I disposed it; the second pair (pictured) is still alive, althouth barely. The cushions are completely gone, but my daughter still uses it on her Technics digital piano; in fact, she prefers them to Sens' 600 she has.

Best,

Eugene
post #32 of 23459
Thread Starter 

Introducing the Elektronika TDS-5M

yvfed1's photos disappeared from his post, but here they are:



This is the Elektronika TDS-5M.

Fascinating! Yes, it looks like someone took casts of the Yamas and made the molds that made yours. Sounds like they may have copied the driver as well-- can you get us a closeup of that?

Replacement earcushions: the Stax SR-X Mk3 pads will fit, but they're not exactly cheap.

What city did these come from?

Deterioration: possibly the connection between the aluminum foil voice coil trace and the connector that leads to the cord, possibly due to electrolytic action. There's really nothing else in an isodynamic driver that could go bad over time. Don't throw them in the disposal before we have a chance to walk you through a possible repair.

.
post #33 of 23459
I don't remember in what city they were made. Please see the pictures of the inside of one driver.

Additionally, I have these Yamaha HPE-170 phones. The retail was $140.00 and Yamaha supplied them with Disclavier series pianos (maybe still does).
They sound somewhat bass-boomy, reminicent of Sony 7506, but very comfortable and insulating. Don't know what's inside.
Best,
Eugene
post #34 of 23459
Thread Starter 
Tantalizing glimpse into another world. Except for the reddish color, the driver looks like a--

Good grief! That driver looks just like the one in the Peerless PMB 100!

I was wondering what city you bought them in. I doubt we'll ever find out precisely where they were made. What else can you tell us about them?

I can tell you that your new Yamaha headphones have a "normal" dynamic element in them, nothing that looks like the insides of your Russian Elektronika TDS-5M.
post #35 of 23459
I don't remember where I bought them - it was many years ago. It was common Soviet practice at the time that the same design could be manufactured on different factories; it well may be the case with those.
Very simillar phones, were made in Ukraine, Lvov city I think.

Best,

Eugene
post #36 of 23459
Hail wualta and everyone,
I just found this site, being referenced in the AudioKarma site, of which I am a member, and joined this site a couple of days ago. Since then I have been reading as many posts as possible with great interest.

Although I have been keenly interested in HiFi since 1979, and have own and own many components, for a reason unknown to me, other than owning and using two pair of headphones, purchased new in 1980, I never entered into this area of HiFi. I am now very interested in it and intend to learn from yall and start a collection of headphones such that I have done with Infinity Loudspeakers over the years.

The reason for my introducing myself in this particular post is that as I am ignorant of headphone technology and the attributes associated with the different brands and models, I started my reading by looking up my headphones in your site. Not finding the brand, I typed in Orthodynamic and have read every shread of information that has been posted on them with interest.

My two headphones are the Burwen PMB 4 and Burwen PMB 8, by one of my favaroite audio legends, Dick Burwen. His site is http://www.burwenaudio.com/.

They are Orthodynamic and although as I stated previously, I am ignorant as to what is considered good or great, I love them, especially the PMB 8 which was his top of the line. They both have been in service by me regularly since 1980, mostly driven out of the headphone jack of an HH Scott 480A Integrated Amplifier, with approximately 20 hours a week usage on the PMB 8 and much less with the PMB 4.

I do not have the spec for the PMB 4, however, the specs for the PMB 8 are as follows:

Model Number PMB 8,
Driver Principle - Orthodynamic,
maximum sound pressure - 112dB at 1 kHz,
impedance - 150 ohm,
Maximum input power - 2W,
Sensitivity - 130mW at 101 dB SPL, 1kHz,
Total Harmonic Distortion - <0.3% at 100dB SPL 1kHz,
Frequency Response - 15-26000 Hz,
Weight 12 ounces


The chit chat on the box that they came in reads; The patented Orthodynamic principle utilizes an ultra thinvoice coil diaphragm, positioned between two perforated disc magnets. The magnets are perforated to allow the sound waves to pass through to the ear. The diaphragm is uniformly driven over it's entire surface. Since the drive units are joined at the center and the edge, the controlled sound reproductionis comparable to that of an elecrostatic unit at twice the price. These orthodynamic stereo headphones feature solid bass response, extremely low distortion even at high sound levels, and excellent transient response.

Burwen Research Inc.
30 Cross street
Cambridge, Massachusetts
Manufacture in West Germany

I paid $108.00 plus tax for these in 1980, which was a piece of change back then. I bought them from a chain that was called Tech HiFi in Framingham, Mass. The reason that I bought these particular headphones was that I knew of Dick Burwen and his inqinuity and reputation for excellence, and also because when I bought the Infinity RS 4.5 loudspeakers I asked the salesman to sell me the best headphones that were available with comparable excellence to the RS 4.5's. Since I walked out of the door with the Burwens on that day, I have never seen, read about or heard of any others. Web site searches turn up nothing. If you have any information concerning these, I would certainly be most interested. I have recently boosted my headphone daily listening to about 5 hours a day now.

I guess the reason that I never looked into replacements or investigated the headphone world further is that I love them tremendously and never imagined anything better. However, the axiom is ' you do not know what you do not know, so here I am saying hail to yall and will be learning as to what is out there, not to ever replaced the Burwen's but to obtain some companion headphones.

Thanks for letting me join yall and I will be reading and learning.

Vito

P.S. The AKG 340 conversations are most interesting.
post #37 of 23459
Quote:
Originally Posted by Vitopanch
Hail wualta and everyone,
I just found this site, being referenced in the AudioKarma site, of which I am a member, and joined this site a couple of days ago. Since then I have been reading as many posts as possible with great interest.

Although I have been keenly interested in HiFi since 1979, and have own and own many components, for a reason unknown to me, other than owning and using two pair of headphones, purchased new in 1980, I never entered into this area of HiFi. I am now very interested in it and intend to learn from yall and start a collection of headphones such that I have done with Infinity Loudspeakers over the years.

The reason for my introducing myself in this particular post is that as I am ignorant of headphone technology and the attributes associated with the different brands and models, I started my reading by looking up my headphones in your site. Not finding the brand, I typed in Orthodynamic and have read every shread of information that has been posted on them with interest.

My two headphones are the Burwen PMB 4 and Burwen PMB 8, designed and developed my one of my favaroite audio legends, Dick Burwen. His site is http://www.burwenaudio.com/.

They are Orthodynamic and although as I stated previously, I am ignorant as to what is considered good or great, I love them, especially the PMB 8 which was his top of the line. They both have been in service by me regularly since 1980, mostly driven out of the headphone jack of an HH Scott 480A Integrated Amplifier, with approximately 20 hours a week usage on the PMB 8 and much less with the PMB 4.

I do not have the spec for the PMB 4, however, the specs for the PMB 8 are as follows:

Model Number PMB 8,
Driver Principle - Orthodynamic,
maximum sound pressure - 112dB at 1 kHz,
impedance - 150 ohm,
Maximum input power - 2W,
Sensitivity - 130mW at 101 dB SPL, 1kHz,
Total Harmonic Distortion - <0.3% at 100dB SPL 1kHz,
Frequency Response - 15-26000 Hz,
Weight 12 ounces


The chit chat on the box that they came in reads; The patented Orthodynamic principle utilizes an ultra thinvoice coil diaphragm, positioned between two perforated disc magnets. The magnets are perforated to allow the sound waves to pass through to the ear. The diaphragm is uniformly driven over it's entire surface. Since the drive units are joined at the center and the edge, the controlled sound reproductionis comparable to that of an elecrostatic unit at twice the price. These orthodynamic stereo headphones feature solid bass response, extremely low distortion even at high sound levels, and excellent transient response.

Burwen Research Inc.
30 Cross street
Cambridge, Massachusetts
Manufacture in West Germany

I paid $108.00 plus tax for these in 1980, which was a piece of change back then. I bought them from a chain that was called Tech HiFi in Framingham, Mass. The reason that I bought these particular headphones was that I knew of Dick Burwen and his inqinuity and reputation for excellence, and also because when I bought the Infinity RS 4.5 loudspeakers I asked the salesman to sell me the best headphones that were available with comparable excellence to the RS 4.5's. Since I walked out of the door with the Burwens on that day, I have never seen, read about or heard of any others. Web site searches turn up nothing. If you have any information concerning these, I would certainly be most interested. I have recently boosted my headphone daily listening to about 5 hours a day now.

I guess the reason that I never looked into replacements or investigated the headphone world further is that I love them tremendously and never imagined anything better. However, the axiom is ' you do not know what you do not know, so here I am saying hail to yall and will be learning as to what is out there, not to ever replaced the Burwen's but to obtain some companion headphones.

Thanks for letting me join yall and I will be reading and learning.

Vito

P.S. The AKG 340 conversations are most interesting.
Pics?
post #38 of 23459
It could well be that your headphones will still sound good by today's standards. Planar headphones are like that. I suspect a proper headphone amplifier, rather than one built into an intergrated amplifier would do it some favours, especially considering how much juice orthos need to full come to life.

Oh yes, and pics!
post #39 of 23459
Thread Starter 
Vito, thanks very much for opening up yet another window into orthodynamic/isodynamic history. I remember Dick Burwen's products from the '70s and have wondered what became of him. I even remember Tech Hi Fi.

It sounds like Burwen imported, and just maybe modified-- photos will tell that story-- the Peerless-MB orthodynamics as described by MB Quart stalwart Willi Presutti in the PMB 100 thread cited in post #34 above. Herr Presutti supplied some excellent photographs as well, which will show you what's probably inside your headphones.

I'm interested in whether, and if so how much, Burwen changed the idiosyncratic Jecklin-inspired earcups of the PMB 100 when he put his name on them. So yes, photos, please, and as soon as possible.

I won't ask you to take them apart, though I'm sorely tempted.

.
post #40 of 23459
I love reading all this stuff and I'm grateful to all who contribute to`such interesting historical topics. So many cool technologies have vanished almost withnout trace over the years and it's great to see people tallk about and be lucky enough to experience them.

My adult headphone journey began with Wharfedale isodynamics in 1976 so I'm very happy to see threads like this as they keep those old gems in memory and interest piqued. I have very fond memories of my isodynamics and the fun I had dissecting them once they broke just to see how they worked.

If I recall correctly the magnets in their housings were bendy, almost like rubber in a way. Not sure after all these years. I certainly put a lot of hours on them as I used to sleep in them every night listening to Capitol radio through a Rotel receiver. Probably why they broke

Thanks for all the great info. I'd love to get another set, sadly they are getting as rare as hens teeth.
post #41 of 23459
Quote:
Originally Posted by wualta
It sounds like Burwen imported, and just maybe modified-- photos will tell that story-- the Peerless-MB orthodynamics as described by MB Quart stalwart Willi Presutti in the PMB100 thread cited in post #34 above. Herr Presutti supplied some excellent photographs as well, which will show you what's probably inside your headphones.

I'm interested in whether, and if so how much, Burwen changed the idiosyncratic Jecklin-inspired earcups of the PMB100 when he put his name on them. So yes, photos, please, and as soon as possible.
I'm not sure whether Willi told me this on the forums or in a private email, but it seems that Joerg Jecklin himself actually advised on the design of the housing for the PMB series headphones (he was working with MB then on the development of his Jecklin disk, and it seems he took the chance to revise his then nearly decade-old float design. Evidently he did not participate in the driver design though, which was done by MB's own engineering team.)

It seems that the history of the PMB headphones is more complex than we knew. Willi Pressuti gave us images and information on the PMB 100 (ortho), 500, and 1000 (electrostat), as well as the later MB Quart Phone 85, a two-way dynamic system in the same float housing. Now we have word of a PMB 4 and 8 either simply imported or transformed in the hands of the inimitable Dick Burwen.

Finally, I've just managed to win yet another PMB headphone which was listed mysteriously as a PMB SL Silvertone. It's in the same housing as the 100/1000/85 (500 is slightly different, with circumaural pads). Until it gets here, I have no clue what kind of driver it's sporting, though I notice it has PMB dual micro plugs and not the later MB single-sided plug I see in PMB pictures, where it appears that the wire is routed to the other side not through the housing, but through the soft headband itself. (update: the Silvertone has one-way dynamic drivers, so it's definitely another version different from the others we've heard of)

How interesting. Unfortunately Willi Pressutti has been very busy lately with actually running his branch of the company, and so we haven't heard from him in a while. Eventually, though, perhaps he'll be able to clarify all this for us.
post #42 of 23459
Thread Starter 
Smeggy, somewhere here HF member setmenu has posted photos of his Wharfedales. Here's one of them:



They're engineered in what I've always thought of as the best British tradition, using inexpensive materials with diehard cleverness, giving an unexpectedly good and often amazing result. They look primitive-- you're right, the magnets are the rubberized kind found in refrigerator magnets (though presumably stronger), and the voice coil is copper that looks like it was drawn on some Mylar with a metallic-ink Sharpie [EDIT: This turns out to've been an incorrect impression from the low-res photos available at the time. The Wharfedale voice coil traces are as precise as any other isodynamic's.] Yet it works and reportedly works well, which demonstrates something about isodynamics that is so far as I know unique: they don't require the levels of precision required by dynamics or electrostatics and can be scaled down in quality of materials without affecting the quality of the sound (though sensitivity and power handling are certainly sacrificed). I hope you find another Wharfedale and bring it here for our delectation. For that matter, I'd love to hear a Wharfedale or Leak isodynamic for myself.

Other isodynamic manufacturers take note: the Wharfedales are open-back! Whatever criticisms one might want to level at them, they at least understood the nature of the beast.

FV, how dare Willi Presutti run his company, and ignore us! What are we, chopped liver?

Anyway, the PMB 6 and 8 might have been PMB model numbers [They were] or Burwen model numbers [Burwen simply copied PMB]. All information will come to us in the fullness of time.


.
post #43 of 23459
Thread Starter 

diagram from Radio Shack

From the owner's leaflet packed with Radio Shack's ca.1980 Realistic Pro-30:



Not the most detailed diagram, but you get a physical sense of the diaphragm immersed in a concentrated, intense magnetic field.
post #44 of 23459
Oh dear, those poor wharfedales look very sad

I guess it's only to be expected after 30 years. They were not too expensive at the time and did sound good to me. I doubt I'll ever find another pair but it's nice to see them again. Funnily enough, I recall them better and more fondly than any girlfriends at the time
post #45 of 23459
Thread Starter 
Quote:
Originally Posted by smeggy
Oh dear, those poor wharfedales look very sad..
They'd been loved and loved until they became real, just like the Velveteen Rabbit.

Quote:
I guess it's only to be expected after 30 years. They were not too expensive at the time and did sound good to me.
I think setmenu feels the same way about his, since he's kept them running all these years. I've heard other people express the same fondness for them.
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