[snowbhoy]

Guys,

Excuse my general ignorance of connector terms, but I've a question for the experts out there.

I have a pair of sennheiser HD 25 SP's (My lovely wife asked around for advice on headphones and got me some for my brithday). They're great.

I have one small problem, I only use my headphones for my ipod and the connector on these things is huge (Big fat adio in style thingie). I got a converter to an ipod type connector but it's loody huge as well, I now seem to have these great size closed headphones with a bloody big connector going into my ipod, which is just too awkward to sit in a pocket, comes loose and generally is annoying.

Is it possible to chop off the end bit and get it rewired, and if so any suggestions where I would go to to get something like this done (I live in London)?

Many thanks.

[cribeiro]

Yes, that can be done. You just need to get the parts, something like this (a gold-plated one would be better, but I cannot find any)

http://electrical.playrecord.net/con....p1021507.html

and use a soldering iron. I do not know in which place you could get it done, but at least I wanted to let you know it is possible

In any case, it is an easy task (10min work) and should not cost you that much.

[trailer]

If you do consider doing it yourself you will need to know which core is which on the old lead so you get the lwft and right channels the correct way.

[per-Sony-fied]

Originally Posted by trailer

If you do consider doing it yourself you will need to know which core is which on the old lead so you get the lwft and right channels the correct way.

FYI snowbhoy (if your wondering how), the easiest way to do this is chop off the end plug with a centimetre or two of wire left (as the end plug is moulded) and strip the wires back to copper & then with a meter check for continuity between each wire & contact pin.

[snowbhoy]

Cheers guys,

Started the process myself - having a few issues.

Stripped the wire back no worriesd (Inc sheathing on core wires), got two leads one with red/blue one with green/grey. I thought red/blue to one and other two to other would work, getting absoultely nothing.

Any ideas?

[StevieDvd]

You need 3 connections. Left, Right & Ground. Is there a metal braiding around the wires - if so that's usually the ground.

Steve

[mattski73]

you just need to give Brian at www.sennheiserspares.com a ring (and leave a message, he will return your call!) and tell him your dilemma, he has the correct cable, i know, i got one from him!

[snowbhoy]

I had one wire with a pair in each 'side'. One side with red / blue, one side with green (Or greenish yellow) and grey (Or siver).

I can get this inner case off pretty easily using a stanley knife and scrapping it off.

Now connected it up - used red/green and blue/grey - styill trying to figure out if they sound ok or not. If I put my connector in all the way they sound very washed out - but I have a case in my ipod which stops it going al the way so sound is fine.

Comparing them to some regular headpones I have, and they have a better base etc but don't sound quite as rich, if that makes sense. Sure if I just picked them up they'd sound fine 0 the difference just the difference between the headsets rather than my solder?

[snowbhoy]

Originally Posted by mattski73

you just need to give Brian at www.sennheiserspares.com a ring (and leave a message, he will return your call!) and tell him your dilemma, he has the correct cable, i know, i got one from him!

So you replaced the whole cable - how? Assuming at the earpiece part itself?

[cribeiro]

As per-Sony-fied suggested, you need to use a multimeter to check where goes which cable.

The original plug has 3 regions on the tip. On the chopped end, you should still be able to reach the core of each cable (red, blue, green and grey). Set the multimeter to measure ohm (lowest ohm region is fine), and check first if the device is working by joining both ends of the probe tips of the multimeter (you should get near zero ohms).

Apply one of the probe tips to the first region of the plug end. Touch each core of the chopped end with the other probe tip, and see which one(s)* give you near zero ohms. Note it down (with a drawing, to avoid confussion).

Do the same for the other two regions of the plug end, and now you know which is which.

EDIT: when you solder, apply heat to the wire and plug contact, then touch the wire with the tin, it should melt and run down the cable and plug contact. Do not apply too much solder, just to cover the joint. Then hold your breath, because it must dry without being moved. The result should be a smooth and gleaming surface (I am not an expert, but the experts where I work explained it to me this way...)

*One region of the plug tip will have two cables connected, this is GND.

[Stompa]

Originally Posted by snowbhoy

I have one small problem, I only use my headphones for my ipod and the connector on these things is huge (Big fat adio in style thingie).

Just a thought (and too late now!) but are you sure you actually had a problem in the first place? Most Sennheiser headphones I've had have come with a 6.3mm plug which separates (by gently pulling) into two parts revealing a 3.5mm one inside.....

And according to:

http://www.sennheiser.co.uk/uk/icm.n...nes_dj_502103#

"Rugged closed dynamic headphone. Max. SPL 120 dB, frequency response 30 Hz to 16 kHz, THD < 0.4 %, nominal impedance 65 ., load rating 0.2 W. 3 m steel cable with 3.5 mm stereo jack plug and adaptor to 1 /4 ” (6.3 mm) stereo jack plug."

Stompa

DEFINITIVE GUIDE TO REPLACE SENNHEISER HD 25 SP CABLE
QUATER INCH JACK WITH MINI JACK FOR PORTABLE MUSIC DEVICES

Ahh, at LAST - is always a hassle to have to register with a forum just to post one reply but it'll be worth it if it helps someone out. - I could not find this information anywhere else and since in the past ppl have helped me with various software/file and also real information on forums I had to post my solution here, even though this post is prehistoric I'm about to wake it up!
This thread is the 5th in Google for searches containing "sennheiser hd 25 sp" and "soldering" so it's probably the best place to post this.

I recieved these headphones from an uncle a few years ago and I was ****** that the jack wasn't switchable (damn you sennheiser!) though I think their new kick-ass models are switchable. I used it for a few months on the street, with a proper quarter inch to mini jack converter but it was WELL cumbersome and after a while the jack on the headphones got damaged and started to cut out a little bit. Drat. Thing is, it was more than a year later (recently) that I though (not being an electrician nor handy with such things at all): "why don't I just solder a new one on??"

First up I checked if there was a mini jack replacement cable which there was at sennheiserspares.com - but it's £25 which is bloody ridiculous.
I can buy a decent jack AND a soldering kit for less than that. So I did.

Eventually I got round to ordering this (I gotta have the best)

Neutrik 3.5mm stereo right angle plug

from

http://www.felmicamps.co.uk/products...ectorsand.html

Good old FEL Communications (thanks guys)
This really is the best mini-jack I have ever seen. Right angle too, perfect for portable audio devices.
Maplins is the WHACK!

Then I ordered a soldering kit for £12 from WOOLWORTHS(.com)
It's a good enough kit - has EVERYTHING and more
thing is, they lost it first and then I emailed them and asked them to send it again - it took 3 weeks in total (so I can't recommend their service - get from store if you can, or just use the one you have, or buy one from somewhere else)

Yo Snowbhoy, did you figure it out?

Here's the technique for replacing the quarter inch jack on the sennheiser hd 25 sp to a mini jack for laptops/iPods etc:

When I severed the cable in half (I just wanted 1.5 meters) I was annoyed to find two wires for left and right channels - four cables in total.
right channel is RED and BLUE, left channel is YELLOW and GREY
***? I though - that's when I searched for this forum.
I couldn't figure out what cribeiro was saying (above) about multimeters - way too much hard work (but cribeiro gives some good soldering advice).
Couldn't find the answer so I made an educated guess - since there are 3 points to solder on the replacement jack, one wire of each channel must carry the signal, and one wire of each channel must ground.
Goes like this:

RED & YELLOW audio channels (right and left respectively - check documentation on your replacement mini jack to check which is which when you solder)

GREY & BLUE are ground. Pretty obvious really but to those who needed a little reassurance, I hope this has been of some use.

GOOD LUCK!

[cribeiro]

Originally Posted by chopstix

I couldn't figure out what cribeiro was saying (above) about multimeters - way too much hard work (but cribeiro gives some good soldering advice).
Couldn't find the answer so I made an educated guess - since there are 3 points to solder on the replacement jack, one wire of each channel must carry the signal, and one wire of each channel must ground.

Thanks chopstix, and welcome to the forums

Regarding the multimeter thing, it is pretty simple, maybe I used too many words In other words, you just check where lands each cable (technically, make a continuity check). You could as well attach a small lamp and a battery to one cable, and see with which part of the plug the lamp is on; and do this for all four cables.

It will work either way, but if you swap signal and ground in one of the channels, the sound will be out of phase. Now, I know this is very bad for loudspeakers, since you basically cancel out bass, but I don't know if it is noticeable over headphones.

I would like to add that you can also use a so-called "balanced" configuration, in which each channel "has its own ground", so to speak. In this case, the headphones sound better, but you need to have a source with balanced outputs, and an amplifier with balanced inputs and outputs.

[cribeiro]

For completeness, just see how to check where goes which cable in the attached picture (a picture speaks a thousand words)