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Orthodynamic Roundup
Oct 18, 2022 at 6:34 PM Post #26,928 of 27,137
If there is one place that holds all the most knowledgeable orthodynamic headphone experts, it's right here. I believe this is the right place to ask, so I will do just that. I have a number of questions and curiosities, but I'll start with one.

Has this voice coil design been implemented before (in a headphone, by a company)? I know there is the usual zig-zag design, then there's the spiral design, and I've seen some use a square spiral design. But this is a combination of a zigzag design and a square line pattern (much like the one of a square wave), which is not something I've seen before.

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Oct 18, 2022 at 10:00 PM Post #26,929 of 27,137
voja said:
If there is one place that holds all the most knowledgeable orthodynamic headphone experts, it's right here. I believe this is the right place to ask, so I will do just that. I have a number of questions and curiosities, but I'll start with one.

Has this voice coil design been implemented before (in a headphone, by a company)? I know there is the usual zig-zag design, then there's the spiral design, and I've seen some use a square spiral design. But this is a combination of a zigzag design and a square line pattern (much like the one of a square wave), which is not something I've seen before.

Click to expand...
The zig zags are just used for diaphragm stability, imho. That is stereotypical serpentine trace layout if you ask me.

I built headphones using these drivers, actually, they are not that amazing.
 
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Oct 19, 2022 at 4:19 AM Post #26,931 of 27,137
khbaur330162 said:
That is stereotypical serpentine trace layout if you ask me.
Click to expand...
What does this exactly mean?

I'm just curious whether this trace layout has ever been used before.
 
Oct 19, 2022 at 7:31 AM Post #26,932 of 27,137
Philimon said:
Are those Aliexpress drivers?
Click to expand...
I bought them off DH Gate. I have seen some of the smaller oval drivers made by this company on Aliexpress, but never this large driver whenever I have checked, although it may be on there.

voja said:
What does this exactly mean?
Click to expand...
Just means straight traces that bend back and forth. Used with bar magnet layout.
voja said:
I'm just curious whether this trace layout has ever been used before.
Click to expand...
Yes, many companies employ this layout: Hifiman, Audeze, Abyss, to name a few. What's interesting is that the little blocks, or zig zag traces as you call them, are driven and current could flow into them and create eddy currents and what have you (they are not within the signal path, so high current is probably unlikely). I would have expected these blocks to be inactive seeing as these areas of the diaphragm should be placed directly underneath the magnets and should be a "dead zone". This characteristic of the layout is unusual and possibly unique.
 
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Oct 19, 2022 at 8:03 AM Post #26,933 of 27,137
khbaur330162 said:
I bought them off DH Gate. I have seen some of the smaller oval drivers made by this company on Aliexpress, but never this large driver whenever I have checked, although it may be on there.


Just means straight traces that bend back and forth. Used with bar magnet layout.

Yes, many companies employ this layout: Hifiman, Audeze, Abyss, to name a few. What's interesting is that the little blocks, or zig zag traces as you call them, are driven and current could flow into them and create eddy currents and what have you (they are not within the signal path, so high current is probably unlikely). I would have expected these blocks to be inactive seeing as these areas of the diaphragm should be placed directly underneath the magnets and should be a "dead zone". This characteristic of the layout is unusual and possibly unique.
Click to expand...
The zig-zag trace layout is sure common, but the voice coil circuit design of the driver I sent is something I've seen for the first time. The part in red is what I am talking about:

Screen Shot 2022-10-19 at 13.45.08.png


It's the first implementation of such design, correct?

khbaur330162 said:
I would have expected these blocks to be inactive seeing as these areas of the diaphragm should be placed directly underneath the magnets and should be a "dead zone".
Click to expand...
If I am not mistaken, this would be incorrect as though these "blocks" are the parts that are exposed. Take a look, and please correct me if I am wrong:

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Oct 21, 2022 at 2:23 AM Post #26,934 of 27,137
Yes, these blocks were the ones I was referring to.

Seems you are correct, the blocks are off-set from the magnets. This is not correct, imho, the serpentine traces should be offset from magnets to incur highest magnetic flux (typically in-between magnets where flux lines jump from magnet to magnet). Something strange is going on. I have verified this characteristic with my own drivers, the blocks are IN-BETWEEN the magnets. Very strange. I have not seen this anywhere else.
 
Oct 21, 2022 at 4:37 AM Post #26,935 of 27,137
khbaur330162 said:
Yes, these blocks were the ones I was referring to.

Seems you are correct, the blocks are off-set from the magnets. This is not correct, imho, the serpentine traces should be offset from magnets to incur highest magnetic flux (typically in-between magnets where flux lines jump from magnet to magnet). Something strange is going on. I have verified this characteristic with my own drivers, the blocks are IN-BETWEEN the magnets. Very strange. I have not seen this anywhere else.
Click to expand...
The truth is that this design is a complete copy of Camerton Audio's Binom-E drivers, designed by Oleh Lizohub.
I have been digging and digging, researching, and I did not come across this design before. The driver you have is a copy of a copy, as though I found a Chinese company that was selling these in 2019. This Chinese company doesn't seem to exist anymore, but I did find it on Pinterest.

Crazy how quick these guys are to copy...
 
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Oct 26, 2022 at 12:36 PM Post #26,936 of 27,137
Hi All!

Vintage Akai ASE-40 Linear Drive Dynamic Headphone.
Driver full size: 65 mm., only membrane: 50 mm.

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http://20cheaddatebase.web.fc2.com/AKAI/ASE-40-J.html

■Price 9,500 yen
■Model Linear drive dynamic type (electrodynamic plane drive type)
■Diaphragm 50 mm 6 micron thick mylar
■Impedance
■Reproduction frequency band 20-20,000Hz
■Allowable input 600mW
■Sensitivity 95dB/mV
■Code 2m
■ Weight 300g (including cord)
Released September 1977
End of sale Around 1982
 
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Nov 28, 2022 at 8:16 PM Post #26,939 of 27,137
Nov 28, 2022 at 8:40 PM Post #26,940 of 27,137
khbaur330162 said:
That's a very high price. Unless buying for collector status due to condition and included packaging you should hope to pay ~$200USD or less for an RP-18.
Click to expand...
Oh ok, Thanks!

How about for a T50? Would you know roughly what a fair price would be for one?
I've seen one go for ~$900 a few years ago, wondering if I should pounce on one if I ever see another one at a similar price.
(Was in decent used condition w/ original hardcase)
 
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