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Headphones (ATH-M50)

yonyz

Aug 23, 2012
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Hi,

I have a pair of M50 stereo headphones by Audio Technica. The right element stopped working so I bought a pair of two new elements (which were both tested to work).

The left element is the one that receives the stereo signal (only one cable goes into the headphones), and it sends the right element's signal to the right elements using a tiny wire that has two wires inside of it: red and bronze.

The problem is with those two red and bronze wires. First, it seems they conduct no electricity, which is super weird. I used a multimeter, touched two points of the bronze wire that are barely 1cm apart, and there's no beeping. Same with the red wire. No idea how that's possible. I should note that I did the same test with other wires, and other unrelated stuff such as my apartment key, and the beeping works fine.

Now to the other problem:
I absolutely cannot solder those two wires, they resist the solder material, they push it aside or something. The headphones have this big cable which contains another three wires (red, green, black) that I was able to solder very easily.

So why do the two wires of the right element signal do not conduct electricity (according to my multimeter) and also do not solder?

Here's a photo of the left element with all the wires. Please advice, those are expensive headphones and I paid a lot for the replacement parts.

Thank you.

193zhi.jpg
 

shrtrnd

Jan 15, 2010
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The small wires are typically coated in laquer, it's cheaper and takes up less room
than other types of insulation on the wires.
I take an exacto-knife or razar blade, and carefully scrap the laquer off the ends of the
wires you want to solder, then you can easily solder them.
My guess is your multimeter isn't reading anything, because you're probes are on
the laquer insulation.
 

yonyz

Aug 23, 2012
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I tried scraping the lacquer (if there's any) with a razor blade and with a stanley knife but it still doesn't solder or conduct electricity... But thanks for the suggestion. I hope it's something else.
 

KJ6EAD

Aug 13, 2011
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Welcome to the wonderful world of litz wire.

http://en.m.wikipedia.org/wiki/Litz_wire

Google "stripping litz wire". You'll find a variety of chemical, flame and mechanical methods touted. I'd try paint stripper first since it's the least likely to damage strands or make them difficult to solder.
 

yonyz

Aug 23, 2012
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I tried different methods. I'm considering buying a solder pot from eBay, but I live in Israel which is the only country in the world to use Type H plug, so I don't know if it will work, and all that AC and Volt stuff I don't about either. I can say that my solder iron has a sticker with this information: 230V~50Hz.

I see 220V items on eBay, nothing that's 230V.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
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220V equipment will normally work on 230V mains.

This assumes the designer has allowed for normal mains voltage variation, of which 230V falls within the expected values for 220V (usually).

I would note that I tend to be wary about making those assumptions with equipment coming from certain countries, however a solder pot is likely to be safe.
 

CocaCola

Apr 7, 2012
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This is one of those instances that US 110/120 voltage SUCKs... I can find a TON of low cost solder pots for 220/240 coming out of Asia but as soon as they make a 110/120 version they double or triple the price for the same thing... Now I could run a 220/240 line but it's a hassle, instead I went with a low cost pewter melting pot for casting figures and an AC 'dimmer' that I already had on hand and presto low cost adjustable solder pot :)

BTW if you do get a cheap Asian solder pot like these

http://s.dealextreme.com/search/solder+pot

Word of advice BEFORE you plug it it, crack the thing open and visually inspect all the internal connections... I have come across several reports of loose or poorly made connections inside these same devices... The price can't be beat though even if you need to fix a bad connection...

And don't forget the flux, dip wire in flux, dip wire in solder, presto...
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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CocaCola makes a good point.

When I referred to "safe" I was talking about voltage ratings that could be sufficiently stretched to cause you problems (edit: and I was forgetting another factor that could be argued is even more important).

Mains wiring is another (and a highly significant) item to check.

edit: And the link you provide below speaks volumes.
 
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CocaCola

Apr 7, 2012
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Steve I understood what you meant, just adding to it from knowledge I found when researching these cheap pots awhile back... These solder pots use a simple resistive sleeve, the excessive voltage can be negated by simply not turning it up all the way :) I personally wouldn't hesitate to use it on 240V...

On that note I had found several reviews when I was looking at them, but can only find this one right now in my bookmarks... In the video(s) he points out some of the assembly issues that could cause a potential short and something to at least be mindful of... Or at least something I would look at before plugging in...

http://blog.elektronicastynus.be/archives/32
 

yonyz

Aug 23, 2012
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Hi guys, eventually I bought a Portasol P50 (PTLP-50) butane soldering iron. I figure it gets hot enough to deal with the average lacquer coating.

Since it's butane powered, I won't have electricity-related problems.
However, I have no idea what butane gas is. Is it the regular lighter gas?

P.S. I bought a new iron cause my current iron pretty much exploded mid-use yesterday, causing a short in the entire home. I bought it specifically to fix the headphones, that crap barely lasted 2 hours of use, not to mention it took a full minute if not more to melt a tiny solder ball, that's why I decided to buy a decent solder iron instead of a cheap solder pot.
 
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CocaCola

Apr 7, 2012
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However, I have no idea what butane gas is. Is it the regular lighter gas?

In the US it's pretty easy to locate, Wal-Mart or any hardware store should have it in stock... Heck a lot of Walgreens and CVS pharmacy corner stores will also carry it...

http://www.walmart.com/ip/Ronson-Multi-Fill-Butane-42g/17133680

http://www.homedepot.com/h_d1/N-5yc...=10053&langId=-1&keyword=butane&storeId=10051

There will be a fill port on the bottom of the torch, rotate the torch so that the port is facing upwards, take the butane refill and press the needle tip into the fill port (butane container is held upside down) keep pressing until it overflows and starts spurting out... Presto you are done... You do it upside down like this so that the liquid butane is what fills the torch not simply the expanded gas... And don't worry about the spill over it evaporates before you can blink...
 

yonyz

Aug 23, 2012
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Thanks, I found (in my country) 220 grams of gas for 5 USD. How many refills are 220g?
 

CocaCola

Apr 7, 2012
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Thanks, I found (in my country) 220 grams of gas for 5 USD. How many refills are 220g?

Well that all depends on the tank size of the solder iron ;)

But, I believe that will be PLENTY of butane to suit you for quite awhile... Many, many, many hours of burn from that large of a container...
 

yonyz

Aug 23, 2012
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It states it's a single use container - what's that? Do I throw it after one refill?
 

CocaCola

Apr 7, 2012
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It states it's a single use container - what's that? Do I throw it after one refill?

Might be the wrong kind, the ones for refillable items have a needle valve on top that allows for multiple uses...

fill2_smaller.jpg
 

KJ6EAD

Aug 13, 2011
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It states it's a single use container - what's that? Do I throw it after one refill?

That just means that the butane canister is not designed to be refilled after it's empty. You can use it as many times as you like to refill the iron.
 

yonyz

Aug 23, 2012
22
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Aug 23, 2012
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So I received the Portasol Pro 50, filled it with butane gas, and tried what's done on this video:

As expected, it does not work. The red and bronze coating does not come off, nothing does. The soldering iron goes as high as 375 degrees Celsius, hopefully that's hot enough.
 

CocaCola

Apr 7, 2012
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That should be plenty hot, did you have a nice tinned tip with a glob of solder like they had in the video as to better transfer the heat off the iron?

I have done this many time with a disposable BIC lighter, it's not hard to get the insulation off unless it's some crazy specialty military grade stuff, that I have never come across... Normal lacquer will burn right off...
 

yonyz

Aug 23, 2012
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Will try with a blob of solder.
How will I know if the coating is off? By the solder blob attaching to the wire?
 
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