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Beyerdynamic T1 cable connection mod

post #1 of 29
Thread Starter 

The modification is easy, invisible and flawlessly reversible. The first step is to disconnect the cable shields inside of the jack plug. This way you decrease the capacitance between the hot wires and the ground. Another step is to separate galvanically one shield from another so that they don't create short circuit. This step is even more significant as you decrease capacitive crosstalk between channels. Instead of shorted screens you have just a minute capacitance remaining between them. So, when you cut or de-solder them off the jack plug, you have to isolate the rest of the copper with insulation tape so it doesn't short with any other pin and the screens don't short together. The white wires remain connected, of course. You have to be careful while distinguishing the copper strands of the shield from the white wire strands. The results are:

- wider soundstage with great feeling of immersion in the music

- I finally enjoy Barocco music like Branderburgian Concertos

- I enjoy classical more

- better microdetail retrieval, slight roundedness in the sounds that some people reported, disappeared

- the Stax Demo CD sounded uncovincing before the mod, and it's one of the best real life illusion after the mod

I made a circuit so that I could short the screens together back and then re-connect them to the ground pin of the jack plug. In such a quick comparison you realize that with the stock connection there is something wrong. Actually, I repeated this experiment because I had done it two years ago prior to making my first DIY re-cable of the Creative Aurvana Live! Then I checked all the combinations of connecting the screens - grounded, floating, shorted, and then knew which was sonically and electrically the best. Even when some handbooks say how to connect the screen, it concerns static signal measurements in general. Here we have music and we care more about transients than steady states, so noise cancellation is less important than undistorted transients and impulses.

The mod is easily reversible by re-soldering the disconnected screen wires. When you like narrow and distant soundstage with small size imaging - don't do it. Otherwise, enjoy! ;) Give yourself at least an hour to discover the new sound after the mod. For me there is no coming back.

 

Below are some instructions for those who don't know the Neutrik NP3X-B plug mechanics.

 

1. Grab the metal jack enclosure tight and twist off the plastic cable shield. The metal enclosure will fall off towards the jack tip.

2. Pull away the plastic shield towards the headphones.

3. Remove the blue strain relief  by unbending it and pulling aside.

4. Look at the soldering of the ground pin. There are two white wires and two shields connected. Un-split the shield wires and disconnect them (cut off, de-solder)

5. Un-split and disconnect left cable screen from the right one.

6. Bend both shielding wires backwards and wrap around with a tape. To make it easier, cut the outer sheath along the middle on a 1/4" distance.

7. Place back the strain relief so that all three wings surround the cable and the bottom border fits the jack tip shaping.

8. Pull back the plastic shield.

9. Put the metal enclosure onto the jack, keep the plastic shield tight and twist on the metal enclosure until the whole thread is hidden. Done.


Edited by majkel - 8/28/10 at 1:33pm
post #2 of 29

So shich is the shield? The white wire, or the loose copper? Most likely the loose copper is the shield.

post #3 of 29

OK the shield was the loose copper. I should have known that "hangs head in shame".....

post #4 of 29
Thread Starter 

You need to disconnect the bare copper surrounding the wire pairs.

post #5 of 29

I did the mod and found the changes to not be so big, but everything you described happened. I think it's worth it.

post #6 of 29

majkel, could you possibly post step by step pictures to go with your instructions, as it'd be very helpful. thanks.
 

Quote:
Originally Posted by majkel View Post

 

Below are some instructions for those who don't know the Neutrik NP3X-B plug mechanics.

 

1. Grab the metal jack enclosure tight and twist off the plastic cable shield. The metal enclosure will fall off towards the jack tip.

2. Pull away the plastic shield towards the headphones.

3. Remove the blue strain relief  by unbending it and pulling aside.

4. Look at the soldering of the ground pin. There are two white wires and two shields connected. Un-split the shield wires and disconnect them (cut off, de-solder)

5. Un-split and disconnect left cable screen from the right one.

6. Bend both shielding wires backwards and wrap around with a tape. To make it easier, cut the outer sheath along the middle on a 1/4" distance.

7. Place back the strain relief so that all three wings surround the cable and the bottom border fits the jack tip shaping.

8. Pull back the plastic shield.

9. Put the metal enclosure onto the jack, keep the plastic shield tight and twist on the metal enclosure until the whole thread is hidden. Done.

post #7 of 29
Thread Starter 

Before I manage to take some pictures I'll try to clarify the cable construction.

Here is a single shielded cable with one pair of conductors. You have two such geometries in the T1's cable.

Stock connection is made that one wire from the pair is connected to left or right channel pin of the jack and the positive pin of the corresponding transducer. Another wire from the same pair is connected to the negative pin of the same transducer on one side and to the ground pin of the jack plug on another side. So, both "returning" wires meet at the same jack pin. Besides the return wires, there are both shields (the outer copper layer) connected to the ground pin of the jack. So this means they are shorted one to another. We don't want this so the only way to achieve the isolation between them is to disconnect them from the ground pin and one from another. How to accomplish this - I have posted above.

The shields aren't connected anywhere at the transducer side which I verified with the multimeter.


Edited by majkel - 8/28/10 at 1:31pm
post #8 of 29

When you take apart the plug you will see a Red, Green, and copper wire (ground). Snip all the wires off the connector and strip the black rubber jacket back about 1/4". each channel has the mash copper shield, hot wire (Green or Red) and the cold wire (looked like copper covered in clear PE). Just separate the copper mesh from the PE wire and tape the mesh down. You will then solder the wire back to the correct pads and re-assemble the jack.

 

I will take a picture for you guys in a bit.

 

EDIT: Here's pictures of the T1 wires, you can see I have the shield wire taped down.

 

GEDC0060.JPG

 

GEDC0058.JPG

 

Quote:
Originally Posted by daveDerek View Post

majkel, could you possibly post step by step pictures to go with your instructions, as it'd be very helpful. thanks.
 


 

Edited by Zombie_X - 8/28/10 at 1:55pm
post #9 of 29
Thread Starter 

@Zombie_X, I'll appreciate your effort as I'm off the bench for a couple of days now.

post #10 of 29

No problem man, and the pictures are up.

So guy's here's the color coding of the wires. Each of the two cables will have three wires.

 

LEFT:

Green Wire - Positive Polarity (+)
Copper Mesh - Shield (Neutral)
Clear Wire - Negative Polarity (-)

RIGHT:

Red Wire - Positive Polarity (+)

Copper Mesh - Shield (Neutral)

Clear Wire - Negative Polarity (-)

 

_________________________________________________________________________________

_________________________________________________________________________________

 

 

For 4-Pin balanced termination you'll need to follow the following wire layout. A 4-Pin XLR will have pins numbered from 1-4. Makes sure you have the on the right solder terminals otherwise it won't work.

 

Pin 1 - Left Positive Polarity (Green Wire)

Pin 2 - Left Negative Polarity (Clear Wire)

Pin 3 - Right Positive Polarity (Red Wire)

Pin 4 - Right Negative Polarity (Clear Wire)

 

_________________________________________________________________________________

_________________________________________________________________________________

 

 

For 3-Pin balanced termination you will need two 3-pin xlr's. The wiring will be as follows.

 

LEFT:

Pin 1 - Copper Mesh (Shield)

Pin 2 - Left Positive Polarity (Green Wire)

Pin 3 - Left Negative Polarity (Clear Wire)

 

 

RIGHT:

Pin 1 - Copper Mesh (Shield)

Pin 2 - Right Positive Polarity (Red Wire)

Pin 3 - Right Negative Polarity (Clear Wire)


Edited by Zombie_X - 8/29/10 at 11:59am
post #11 of 29

Does anyone have pictures of this mod on the standard 1/4 plug? I'm not sure I follow the order on how to reconnect each wire :( 

post #12 of 29

I decided to do this simple mod so here are my pics:

 

Before any change:

 

IMG_3364.JPG

 

IMG_3365.JPG

 

 

De-soldering the shield wires:

 

IMG_3368.JPG

 

IMG_3369.JPG

 

IMG_3370.JPG

 

Taped off

 

IMG_3371.JPG

 

 

So far I've listened to several reference tracks. My T1 has approx. 400 hours and my amp is a Woo Audio 3. I wish I had time to set up a test circuit as majkel did to clearly hear the differences...but, I believe I'm hearing an improved soundstage and overall less congested sound. I think it is an improvement however small. This mod takes 10 minutes and is reversible but I have no plans to do that.

post #13 of 29

Thanks for taking the time to put up pics with the 1/4 inch plug. This mod is even easier than I thought.

post #14 of 29
Thread Starter 

Thank you, Great Dane for your efforts! Now the thread is complete. smily_headphones1.gif

post #15 of 29
Quote:
Originally Posted by majkel View Post

Thank you, Great Dane for your efforts! Now the thread is complete. smily_headphones1.gif



Thank you for the insight to begin with. I'm not much of a DIY'er but this was too easy not to try...and well worth it.

 

I hope other T1 owners try it. I'd like to see more impressions.

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