Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Could a poorly soldered 4-pin XLR for headphones cause static and left/right volume difference?
New Posts  All Forums:Forum Nav:

Could a poorly soldered 4-pin XLR for headphones cause static and left/right volume difference?

post #1 of 14
8/21/10 at 6:43pm
Thread Starter 

I switched the two 3-pin XLRs to one 4-pin XLR on my headphones. When plugged into my brand new Little Dot VII+ amp, there is static even with the volume on 0 and the left side volume is a little lower than the right when I play audio.

 

Could this be caused by a poor solder job on my part?

Reply
post #2 of 14
8/22/10 at 12:00am

Yeah, I do not see why it could not

Reply
post #3 of 14
8/22/10 at 8:42am

If the 4-pin is wired properly there should be no difference beyond being more convenient to plug in and never going into idiot mode and flipping L&R

 

If the 4-pin is not wired properly, with a few wires flipped (IE 1 left wire hooked up to a right pin, and 1 right wire hooked up to a left pin) I can see VERY weird things happening.

 

What pinouts did you use, and have you verified them with a meter after everything is done?
 

Quote:
Originally Posted by krmathis View Post

Yeah, I do not see why it could not


I think something got lost in translation. 

Reply
post #4 of 14
8/22/10 at 12:46pm
Thread Starter 

I followed the schematic from the Little Dot VII+ manual.

 

My headphones had a red marked 3-pin XLR and a white marked 3-pin XLR. When I pulled the XLR connectors off, the red side (right) had a green and white wire. I put the green wire into R+ and the white wire into R-. The white side (left) had a red and black wire. I put the red wire into L+ and the black into L-.

 

When playing audio, the left and right channels are correct.

 

My two problems are....

 

1. Left channel audio is not as loud as right channel audio.

 

2. With the volume on 0 and everything else turned off (i.e. DAC, computer, etc. etc.), there is static coming out of both the left and right channels.

 

I tried some SE headphones out of the 1/4" output and there is no static, so I am convinced my solder job was poor. I just wanted to know if bad soldering could indeed cause the problems mentioned above.

 

Thanks guys!


Edited by Zorlac - 8/22/10 at 12:47pm
Reply
post #5 of 14
8/23/10 at 3:56am

 

 

All you had to do was take note of the polarity of the cables in the 3 pin and transfer to 4 pin.

 

Are you sure that the green was + and likewise the red,reduced volume can be caused by reverse polarity on one side.

 

Some other people have mentioned noise on one channel with these amps so it might not be your XLR.

 

I have a VII that I returned because of noise in one channel,it was fixed and has run perfect ever since.

Reply
post #6 of 14
8/23/10 at 7:30am

Flipping phase does not normally cause noise. If it was quiet with the 2X3pin it should be quiet with the 4-pin.

Reply
post #7 of 14
8/23/10 at 9:18am
Originally Posted by nikongod View Post


I think something got lost in translation. 


Lost where?

Answer seems to fit with both of the questions.
 

Originally Posted by Zorlac View Post

Could a poorly soldered 4-pin XLR for headphones cause static and left/right volume difference?
Could this be caused by a poor solder job on my part?



 


Edited by krmathis - 8/23/10 at 9:19am
Reply
post #8 of 14
8/23/10 at 2:02pm
Thread Starter 

Yeah, I am sure my polarity is correct.

 

Volume is lower on the left than the right AND both channels have static even when the volume is at zero.
 

Quote:
Originally Posted by ford2 View Post

 

 

All you had to do was take note of the polarity of the cables in the 3 pin and transfer to 4 pin.

 

Are you sure that the green was + and likewise the red,reduced volume can be caused by reverse polarity on one side.

 

Some other people have mentioned noise on one channel with these amps so it might not be your XLR.

 

I have a VII that I returned because of noise in one channel,it was fixed and has run perfect ever since.

Reply
post #9 of 14
8/23/10 at 4:09pm



 

Quote:
Originally Posted by nikongod View Post

Flipping phase does not normally cause noise. If it was quiet with the 2X3pin it should be quiet with the 4-pin.


Who said it could cause noise?.IF you read my reply it relates to Volume.


 

Quote:
Originally Posted by Zorlac View Post

Yeah, I am sure my polarity is correct.

 

Volume is lower on the left than the right AND both channels have static even when the volume is at zero.
 


 


I can only suggest that you try another pair of phones in the balanced mode,if they are noisy to then get in touch with David.

 

I suppose that you have tried the amp from different mains circuits and with nothing else plugged in?

 

I have no noise at all on my VII even with phones of 32 ohm's and a Sensitivity of 104dB/mW.
 


Edited by ford2 - 8/23/10 at 4:13pm
Reply
post #10 of 14
8/23/10 at 4:48pm

Sorry about that. I re-read what you wrote, and it was about the volume error. Flipping phase does not normally cause volume changes. What you wrote was wrong.

 

to the OP: 

it is rare to solder something so poorly that it causes static. 

 

What are the pinouts? Can you measure the resistance of the headphone across pins 1&2 and pins 3&4 on the headphone plug? what values do you get?


Edited by nikongod - 8/23/10 at 4:59pm
Reply
post #11 of 14
8/23/10 at 5:08pm
Thread Starter 

Thanks for all your help guys. I had a new Neutrik professionally soldered today on my headphones by a local cable manufacturer/reseller. They did an awesome job using my Furutech solder.

 

Got home and tested and the problems persist.

 

Just for the record, I have tried different power cables, different fuses, RCA caps since I am only using the two 3-pin XLR inputs, moving the amp away from all other equipment, adjusting the gain settings, etc. The problem persists as usual. The 1/4" SE output works just fine. I am convinced the new LD VII+ is faulty when it comes to the 4-pin XLR output.

 

I have contacted David with Little Dot and am awaiting a reply.

 

Zorlac

Reply
post #12 of 14
8/23/10 at 5:11pm
Quote:
Originally Posted by nikongod View Post

Can you measure the resistance of the headphone across pins 1&2 and pins 3&4 on the headphone plug? what values do you get?


please.

Reply
post #13 of 14
8/23/10 at 5:27pm
Thread Starter 

pins 1&2 and pins 3&4 are both showing almost exactly 23.5 Ohms on my DMM. Does this sound right? I am guessing it is considering my Denon D7000 headphones are rated for 25 Ohms.  :)

Reply
post #14 of 14
8/23/10 at 5:29pm

yes, that sounds right. It is normal for there to be some variance from the nominal impedance.

 

Very weird. 

Reply
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Could a poorly soldered 4-pin XLR for headphones cause static and left/right volume difference?