Orthodynamic Roundup

[ludoo]

16 years, and I'm still playing with the Yamaha HP-3. I have stopped using them a long while ago, but they still occupy a soft spot in my audio heart. I have accumulated so many of them over the years, that I still hope to get them to a point where I can use them for travel or bed listening, without them making me regret my other headphones.

To make things simpler I used a very cheap rig for today's damping exercise: a USB-C Dongle (Apple or possibily Google) and a 10$ Chinese amplifier. This is the kind of gear I would use with the HP-3 anyway. As a reference for mods I used one of my TDS-15, which are tuned to my exact liking and match pretty closely the Stax SR-L500 FR, at least on my rig (the Stax sound faster and more refined of course).

Spoiler: open for measurements

This is the "naked" HP-3 with no damping inside, just the driver fixed to the baffle with thin 3M film, and recabled with Mogami mini quad. Not a nice sight.

I then tried a few variations with Micropore, but I ended up not using it: you need to cover most of the driver to have measurable effects, and once you do it smoothens mids too much. This is one the effect of a strip of micropore covering most of the driver.

In the end I settled on 1cm polyurethane foam, the same material often used for earpads filling. It sounds counterintuitive, but I had great results using it with the TDS-15 instead of more traditional felt damping. In the back of the cups I used a thin polyester layer from an air purifier filter.

This is more like it. I mentioned the Stax SR-L500, this is a measurement on the same rig: if you discount the usual Lambda bass hump+drop due to the difficulty of sealing pads on the measurement rig, the TDS-15 have very similar FR and the HP-3 have got a lot closer.

 

[JiomBbon]

16 years, and I'm still playing with the Yamaha HP-3. I have stopped using them a long while ago, but they still occupy a soft spot in my audio heart. I have accumulated so many of them over the years, that I still hope to get them to a point where I can use them for travel or bed listening, without them making me regret my other headphones.

To make things simpler I used a very cheap rig for today's damping exercise: a USB-C Dongle (Apple or possibily Google) and a 10$ Chinese amplifier. This is the kind of gear I would use with the HP-3 anyway. As a reference for mods I used one of my TDS-15, which are tuned to my exact liking and match pretty closely the Stax SR-L500 FR, at least on my rig (the Stax sound faster and more refined of course).

It’s great to hear that the Yamaha HP-3 still holds a special place for you after 16 years! It’s impressive that you’re still experimenting with mods, even with a simple setup like the USB-C dongle and a budget amp. Finding the right sound for travel or casual listening is definitely a fun challenge. Using your TDS-15 as a reference for mods makes a lot of sense, especially since they’re tuned to your liking and closely match the Stax SR-L500's frequency response. How are the modifications coming along? Any noticeable improvements in comfort or sound with the HP-3?

 

[voja]

I come here once again to kindly borrow the invaluable knowledge and expertise of the thread's members.

Last time, I used the gathered information for my thread, which was an attempt to put together a chronological timeline of planar-magnetic headphone releases. It was a minuscule effort compared to this thread.

Now, I'm doing more research on YAMAHA, which has me more intrigued by the day. I'm interested in the orthodynamic technology and name conception. Those of us who are just enthusiastic enough to be familiar with the term orthodynamic, associate it with YAMAHA. I myself was convinced that it was YAMAHA who 'invented' it with their HP-1. As far as HP-1 is concerned, its release date is more often reported to be 1976, while some sources claim it was 1975 or even as early as 1974. I am uncertain whether the HP-1's driver was corrugated or not, but I am led to believe it was.

According to: http://20cheaddatebase.web.fc2.com/yamaha/yamahaindex.html there is a speculation that Peerless is the original creator of the orthodynamic driver type. This was also suggested by some members here (it was even said that YAMAHA may have used the drivers under a Peerless license). However, it is unclear to me whether Peerless' PMB-8 and PMB-6 even used a corrugated diaphragm or not.

The whole topic of headphone history is very complex to research. It feels like trying to piece together an unsolved crime. Information is scattered all over the internet, with the most valuable sources long gone... Regardless, I remain passionate and enthusiastic about learning more about such small details =)

Would greatly appreciate the help of the knowledgeable people from here

 

[szerecsen]

voja: cant tell if Peerless and Yamaha were somehow cooperating or not, sorry, however, it seems highly unlikely, as all the large fostex made planars declare on their boxes the Rank Organization (wharfedale mother company) to be the licence holder for the technology (see this pic for ex.), so, it is quite reasonable to assume that planar technology entered Japan in the early 70's without Peerless's intervention

a replacement driver has just arrived for one of my dk_830s with a crackling right side



cheers,

szerecsen

 

[voja]

voja: cant tell if Peerless and Yamaha were somehow cooperating or not, sorry, however, it seems highly unlikely, as all the large fostex made planars declare on their boxes the Rank Organization (wharfedale mother company) to be the licence holder for the technology (see this pic for ex.), so, it is quite reasonable to assume that planar technology entered Japan in the early 70's without Peerless's intervention

a replacement driver has just arrived for one of my dk_830s with a crackling right side



cheers,

szerecsen

This is why I ask. It's about who did it first, and did they license it to other early manufacturers to feature this technology. As for planars, that's another case that I'm currently not looking into. I know Wharfedale was the first to come out with the planar technology in the headphone field, so that explains how their parent company, Rank Organization, was the license owner for the technology.

I'm specifically interested in who was the first to make the Orthodynamic driver type, which appears to be a separate technology. I believed it was Yamaha until I came across sources that claim it was Peerless who was first. It's also been said that Peerless claimed the term Orthodynamic as their innovation and their patented technology. I looked at Peerless' PMB-8 and PMB-6 drivers, and from the pictures at least, their diaphragm looks flat.

The term orthodynamic has been used way before its use in the headphone industry. This makes me wonder what was Peerless' definition of "Orthodynamic". Knowing Yamaha's background in engineering and in-house manufacturing, I highly—HIGHLY—doubt that Yamaha would use the driver technology under Peerless' license, nevermind copy it. Yamaha was a huge company even at that time, and it was only continuing to expand. I would say that it branched out the most during the 60's, 70's, and 80's.

It is known that the HP-1 arrived to the US market in the fall of 1976, and some sources report that they were released as early as 1975 in the domestic market. I do not know when the Peerless headphones were released domestically, but it doesn't sound likely at all that Yamaha used Peerless' license. Using some logical way of thinking, it's safe to assume that Yamaha developed its own Orthodynamic driver with the corrugated diaphragm.

If you know anything about this subject, please chime in

 

[GREQ]

In the 1986 movie 'Fugitive Alien' there appears to be a modified Otto ET-1000.

I always enjoy recognizing headphones in movies/TV.
I thought this time, since it was something so rare, I had to share it

 

[szerecsen]

I believe to see a pair of T20 at 0:33.

 

[rx170ec]

voja: cant tell if Peerless and Yamaha were somehow cooperating or not, sorry, however, it seems highly unlikely, as all the large fostex made planars declare on their boxes the Rank Organization (wharfedale mother company) to be the licence holder for the technology (see this pic for ex.), so, it is quite reasonable to assume that planar technology entered Japan in the early 70's without Peerless's intervention

a replacement driver has just arrived for one of my dk_830s with a crackling right side



cheers,

szerecsen

amazing!! where did you get it?

 

[szerecsen]

amazing!! where did you get it?

pm sent

 

[pezhore]

Not sure if this is the best place to put this, but I picked up two Yamaha HP-2 headphones on ebay (the listing for one was mislabeled YH-2 and I didn't realize it until it was too late). While taking them apart to clean/prep for refurb'ing, I noticed the two drivers were fairly different - one with a larger quantity of holes, and they were square vs fewer circular holes.


The one on the left has the serial number 782797, the one on the right is 662683. Both headbands are identical, sporting the Mario Bellini signature.

Any ideas why the difference? The one on the right is in way better shape, thoughts on if I should swap the drivers around?

 

[Philimon]

pm sent

We all want to know! Really neat!

Any ideas why the difference? The one on the right is in way better shape, thoughts on if I should swap the drivers around?

Ive heard tell of early HP-2 having square magnets. Ive not searched the topic myself nor seen photos so probably rare. Seems like a lot less magnet on the squared version which I imagine is good and bad. Im curious to try, please send me a dm if you decide to sell.

 

[szerecsen]

https://www.dualfred.de/Amplifier-T...Loudspeaker/Loudspeaker-Crossover-Headphones/

One last 830 driver available.

 

[GREQ]

Not sure if this is the best place to put this, but I picked up two Yamaha HP-2 headphones on ebay (the listing for one was mislabeled YH-2 and I didn't realize it until it was too late). While taking them apart to clean/prep for refurb'ing, I noticed the two drivers were fairly different - one with a larger quantity of holes, and they were square vs fewer circular holes.


The one on the left has the serial number 782797, the one on the right is 662683. Both headbands are identical, sporting the Mario Bellini signature.

Any ideas why the difference? The one on the right is in way better shape, thoughts on if I should swap the drivers around?

The square-hole magnets with the earlier serial numbers were definitely more difficult and more expensive to manufacture and likely had a higher failure rate.
I don't think there's any big secret as to why they switched to round holes later on.

 

[pezhore]

Ive heard tell of early HP-2 having square magnets. Ive not searched the topic myself nor seen photos so probably rare. Seems like a lot less magnet on the squared version which I imagine is good and bad. Im curious to try, please send me a dm if you decide to sell.

My plan is to refurb both and give them a head-to-head comparison. The square ones are all set now with the felt/cardstock/felt mod, new earpads and headband. I'll be getting more pads later this week. I really wish I had anyway to actually measure frequency responses, it's been on my to-do list for a while to build a setup.

 

[voja]

This is why I ask. It's about who did it first, and did they license it to other early manufacturers to feature this technology. As for planars, that's another case that I'm currently not looking into. I know Wharfedale was the first to come out with the planar technology in the headphone field, so that explains how their parent company, Rank Organization, was the license owner for the technology.

I'm specifically interested in who was the first to make the Orthodynamic driver type, which appears to be a separate technology. I believed it was Yamaha until I came across sources that claim it was Peerless who was first. It's also been said that Peerless claimed the term Orthodynamic as their innovation and their patented technology. I looked at Peerless' PMB-8 and PMB-6 drivers, and from the pictures at least, their diaphragm looks flat.

The term orthodynamic has been used way before its use in the headphone industry. This makes me wonder what was Peerless' definition of "Orthodynamic". Knowing Yamaha's background in engineering and in-house manufacturing, I highly—HIGHLY—doubt that Yamaha would use the driver technology under Peerless' license, nevermind copy it. Yamaha was a huge company even at that time, and it was only continuing to expand. I would say that it branched out the most during the 60's, 70's, and 80's.

It is known that the HP-1 arrived to the US market in the fall of 1976, and some sources report that they were released as early as 1975 in the domestic market. I do not know when the Peerless headphones were released domestically, but it doesn't sound likely at all that Yamaha used Peerless' license. Using some logical way of thinking, it's safe to assume that Yamaha developed its own Orthodynamic driver with the corrugated diaphragm.

If you know anything about this subject, please chime in

I even contacted Peerless. No reply.