In article ,
"Dave Plowman (News)" wrote:

In article ,
Patrick wrote:
I have some vinatge headphones (Sennheiser HD424) and want to attach a
new plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead
black & yellow. (No wire is used as screening - there's just two wires
in each lead.)

Black and blue are the commons. Not that it would make any difference if
you commoned red and yellow.

You can check for sure by unplugging the leads from each actual earpiece
(red and blue plugs), but be careful to pull on the actual plug only. The
pins are of slightly different sizes.

Hope you have a source of the muffs for these - they crumble to dust quite
quickly.

I've been making my own for years, out of open-cell foam -- it comes for
free as packaging in all sorts of product boxes.

Isaac

On May 14, 9:07*pm, isw wrote:
In article ,
*"Dave Plowman (News)" wrote:



In article ,
* *Patrick wrote:
I have some vinatge headphones (Sennheiser HD424) and want to attach a
new plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead
black & yellow. *(No wire is used as screening - there's just two wires
in each lead.)

Black and blue are the commons. Not that it would make any difference if
you commoned red and yellow.

You can check for sure by unplugging the leads from each actual earpiece
(red and blue plugs), but be careful to pull on the actual plug only. The
pins are of slightly different sizes.

Hope you have a source of the muffs for these - they crumble to dust quite
quickly.

I've been making my own for years, out of open-cell foam -- it comes for
free as packaging in all sorts of product boxes.

Any tips how? I once bought a Pelican case to hold something
disassembled, and I had a heck of a time cutting cavities in the foam
provided to fit the pieces. Cutting foam into cylinders would be hard
enough -- making them so they can slip over the earpieces seems
nightmarish to me.

In article
,
spamtrap1888 wrote:

On May 14, 9:07*pm, isw wrote:
In article ,
*"Dave Plowman (News)" wrote:



In article ,
* *Patrick wrote:
I have some vinatge headphones (Sennheiser HD424) and want to attach a
new plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead
black & yellow. *(No wire is used as screening - there's just two wires
in each lead.)

Black and blue are the commons. Not that it would make any difference if
you commoned red and yellow.

You can check for sure by unplugging the leads from each actual earpiece
(red and blue plugs), but be careful to pull on the actual plug only. The
pins are of slightly different sizes.

Hope you have a source of the muffs for these - they crumble to dust quite
quickly.

I've been making my own for years, out of open-cell foam -- it comes for
free as packaging in all sorts of product boxes.

Any tips how?

Start with a piece of open-cell foam about 1/2" thick.

In a piece of 1/8" thick stiff material (I used Masonite), cut a round
hole a bit smaller than the diameter of the headset drivers (this will
allow the foam to stretch slightly when you install the pads, so it'll
stay in place).

Put the masonite on the foam and press it down hard (use clamps). The
foam will bulge up in the hole.

With a very sharp small-bladed utility knife, cut around the hole to
free the foam so it stands up in a straight-sided cylinder. Be careful
not to cut all the way through. Then slide the blade across the hole
while using a sawing motion. This will cut off the middle part of the
foam.

Now, you should have a piece of 1/2" thick foam with a circular part in
the middle which is 1/8" thick. Trim the outside to a circular shape, a
bit larger than the drivers.

Of course, you can use a different thickness of masonite to control the
thickness of the foam where the sound comes through, if you like a
"softer" fit on your ears.

Isaac

Patrick wrote...

I have some vinatge headphones (Sennheiser HD424) and want to attach a new
plug.

The colors in one of the leads are red & blue and in the other lead
black & yellow.

Which color wires are the positive ones?

Quite a coincidence; I replaced the plug on my HD490's yesterday and
hacked the moulded plug apart to check.


Red is Right, Yellow is Left, black and blue are common.

For the plug; tip is left, ring right and sleeve common.



--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

"UnsteadyKen"

Which color wires are the positive ones?

Quite a coincidence; I replaced the plug on my HD490's yesterday and
hacked the moulded plug apart to check.

Red is Right, Yellow is Left, black and blue are common.

For the plug; tip is left, ring right and sleeve common.


** Nothing is GUARANTEED to be correctly wired by simply assuming colour
codes are as intended.

After any repair, a final test is always the proper and professional thing
to do - ask any service tech.

It is sooo simple to test if a pair of head phones are wired in phase, all
you need is a mono signal or a AA cell as I suggested to the ****wit OP with
his old Sennheisers.

Using the 1/4 inch stereo plug, connect your mono signal across the tip and
ring only (ie out of phase) and compare the results to when the signal is
wired across tip and ring linked and common ( ie in phase).

Take only seconds and is very conclusive.


..... Phil

Patrick wrote:
I have some vinatge headphones (Sennheiser HD424) and want to attach a new
plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead black &
yellow. (No wire is used as screening - there's just two wires in each
lead.)

From my years of tinkering with old stereo headphones as a teenager, I'm
going to confidently guess:

Black - Left Ground/-ve
Yellow - Left +ve

Blue - Right Ground/-ve
Red - Right +ve


Martin

On Sat, 14 May 2011 22:33:49 +0100, Fleetie
wrote:

Patrick wrote:
I have some vinatge headphones (Sennheiser HD424) and want to attach a new
plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead black &
yellow. (No wire is used as screening - there's just two wires in each
lead.)

From my years of tinkering with old stereo headphones as a teenager, I'm
going to confidently guess:

Black - Left Ground/-ve
Yellow - Left +ve

Blue - Right Ground/-ve
Red - Right +ve


Martin

Sounds right.

RL

"legg"


Sounds right.


** The OP's headphones are not right until they do.



..... Phil

"Patrick" wrote in message
...
I have some vinatge headphones (Sennheiser HD424) and want to attach a new
plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead black &
yellow. (No wire is used as screening - there's just two wires in each
lead.)

Wire them up to a mono source and insert a dpdt switch so you can
easily and quickly reverse the phase of one earpiece. Insert a PVC
T coupling between the earpieces. Compare the sound levels coming
from the bottom of the T while flipping the switch. Loudest is in phase.
Art

Artemus wrote:

"Patrick" wrote in message
...

I have some vinatge headphones (Sennheiser HD424) and want to attach a new
plug.

Which color wires are the positive ones?

The colors in one of the leads are red & blue and in the other lead black &
yellow. (No wire is used as screening - there's just two wires in each
lead.)


Wire them up to a mono source and insert a dpdt switch so you can
easily and quickly reverse the phase of one earpiece. Insert a PVC
T coupling between the earpieces. Compare the sound levels coming
from the bottom of the T while flipping the switch. Loudest is in phase.
Art


But!, Are the ears in phase? :~j

Jamie