Orthodynamic Roundup
Mar 27, 2017 at 1:24 PM Post #24,782 of 27,121
I mean, it really depends what you are trying to do. 
 
The early yamaha and pmb drivers of course are pinched in the center with spiral traces. audio-technica, sfi, fostex spiral drivers have a double-sided spiral that connects in the center. 
 
All i meant was, you get a couple magnetic steel discs, with holes in them, and cover one side of each with small neodymium magnets, poles aligned, and leave the holes open. They should act as one focused magnet each. 
 
All of the designs that use a single ferrite magnet on each side have none of this alternating pole stuff. They just push two magnets together, with opposing forces. 
 
If you are doing a serpentine trace, you'd want slotted steel plates instead, and maybe you do the alternating poles thing. 
 
My understanding of magnetism is somewhere between juggalo and faraday, so I'm not really an expert here. There's reading to be done obviously. 
 
You can buy really long neodymium bar magnets, but the longer you look for, the more expensive they are. 
 
I have some Monsoon panel speakers that are suffering from failed plating on the magnets, and I'm considering replacing all of the 60mm long bar magnets with 15mm bar magnets acquired through aliexpress. I'll need 180 of them if i remember right - a block of 200 is just $14. I'm balking at the moment because i think this task will require complete disassembly of the drivers followed by long soaks in solvents to weaken the original glue, and might result in destruction of the damping pad on the rear magnet structures. And i don't have a plan for how to deal with the alternating pole design. 
 
But these MM1000 panels are just slotted steel plates with bar magnets, and a non-tensioned diaphragm with a serpentine trace. 
 
Mar 27, 2017 at 5:18 PM Post #24,783 of 27,121
I have half dead TDS-16. Haven't used them for a while because of flat ear pads. Today I finally got around to replacing pads - and one headphone is silent. I took them apart to see what was going on (suspecting broken cable) and it turned out the face side magnet was broken into 3 pieces. The diaphragm seems intact, I even got them to make a sound for a second when moving the magnet pieces slightly. 
 
I could try to get a replacement driver from Ukraine, but it would be an organisational nightmare. Any chances of gluing the magnet together?
 
Mar 27, 2017 at 6:37 PM Post #24,784 of 27,121
  I have half dead TDS-16. Haven't used them for a while because of flat ear pads. Today I finally got around to replacing pads - and one headphone is silent. I took them apart to see what was going on (suspecting broken cable) and it turned out the face side magnet was broken into 3 pieces. The diaphragm seems intact, I even got them to make a sound for a second when moving the magnet pieces slightly. 
 
I could try to get a replacement driver from Ukraine, but it would be an organisational nightmare. Any chances of gluing the magnet together?

 
I don't know that the magnets can be repaired, but, this doesn't look like an organizational nightmare to me: 
 
http://www.ebay.com/itm/112347556259
 
Mar 27, 2017 at 6:57 PM Post #24,785 of 27,121
Thanks a million for this link, it did not turn up in my ebay search for some reason. I only found a pair of drivers in Ukraine. I did get things from Ukraine and Russia before, payments and shipment costs were a problem - that's what I meant by "organizational nightmare". Otherwise I would buy a few of these headphones, they are quite common and cheap there.
 
I'll try to glue the magnet, if it doesn't work, I'll try to get the drivers from ebay - if the price doesn't jump too high. Obviously I wouldn't want to spend more than I paid for the headphones :)
 
 
Edit: I glued the magnet back together but the driver still doesn't work. Not everything can be fixed I guess.
 
Apr 6, 2017 at 3:52 PM Post #24,786 of 27,121
  Thanks a million for this link, it did not turn up in my ebay search for some reason. I only found a pair of drivers in Ukraine. I did get things from Ukraine and Russia before, payments and shipment costs were a problem - that's what I meant by "organizational nightmare". Otherwise I would buy a few of these headphones, they are quite common and cheap there.
 
I'll try to glue the magnet, if it doesn't work, I'll try to get the drivers from ebay - if the price doesn't jump too high. Obviously I wouldn't want to spend more than I paid for the headphones :)
 
 
Edit: I glued the magnet back together but the driver still doesn't work. Not everything can be fixed I guess.

http://www.ebay.com/itm/Matched-pair-of-50-mm-drivers-for-Echo-orthodynamic-headphones-New-Old-Stock-/112361276319?hash=item1a2941039f:g:-9wAAOSwAANY5nyM
 
Apr 7, 2017 at 8:00 PM Post #24,788 of 27,121
Yeah, well, not from me. The first auction ended at the price I paid for the whole headphones, looks like the current one will too. I decided to wait for a local ad, or buy from Ukraine after all. I also have TDS-15 and TDS-5, I can wait. I checked the history of ads, TDS-16 do pop up every few months for about $20. But thanks ericj and micon, I do appreciate your effort to help me out.
 
Apr 7, 2017 at 8:16 PM Post #24,789 of 27,121
good to know about those driver magnets being on ebay. I got myself TDS 16 and i hope the magnets don't break.
 
Apr 14, 2017 at 1:33 AM Post #24,791 of 27,121
If anyone is interested, I have uploaded models of the Circumaural adapter plate for the AIWA HP-500 here - http://www.thingiverse.com/thing:2241420

These can be scaled and the .STL file can be slightly modified to be used with other Fostex and Sansui counterparts, I think. 




 
 
 

 



 

 
 
 

 
Apr 22, 2017 at 3:29 PM Post #24,794 of 27,121
  So I'm slowly putting things together to do a diy ortho. Got some capacitor foil in 4 microns and mylar in 1.6 microns planned. Do you dudes think that the poles can be done with two neodymium ring magnets? This would be for a quite small design. Here's a mock-up of what I mean. 

Yea, looking almost exactly like YH-5m
 
May 17, 2017 at 7:32 PM Post #24,795 of 27,121
Hi everybody,
I'm reading old posts for a while now ... I'm currently at 1492, I have just read close to half of the posts!,
I don't remember what motivated me to buy a t20v1 but after moding it, it's sound its very good. Since I'm checking
for other models to try...
I found in ebay

$_12.JPG


$_12.JPG

looks like an ortho but I didn't found any information anywhere! someone have some information about it?
the seach inside a thread doesn't exist anymore.

$_12.JPG


I avoid to name it!
 

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