[morph2k4]

Sorry if this is the wrong forum, I wasn't sure since it involves both cans and source gear.  I'm getting some weird behavior after re-cabling my t5p.  I just finished installing HD800 connectors in each cup, and I'm now testing the t5p alongside my HD800 with my home rig.  When I run the t5p through the stock HD800 cable into the magni/modi, I get tons of static in both earcups.  Additionally, tapping either ear cup makes a static pop sound from that ear.  The weird thing is that the HD800 exibits none of these symptoms, and the t5p exibits none of these symptoms run from my logitech computer speakers (same volume as the magni).
 
To summarize:
1.  t5p + stock HD800 cable + magni/modi = TONS of static
2.  t5p + stock HD800 cable + logitech amp = perfect sound
3.  HD800 + stock HD800 cable + magni/modi = perfect sound
4.  HD800 + stock HD800 cable + logitech amp = perfect sound
 
As far as I can tell. the t5p is somehow incompatible with the magni.  I've never tried to drive it off the magni before, since the t5p live in my office connected to a low gain valhalla 2.  I really wish I'd tested for some baselines before doing the mod.
 
The HD800 connectors are attached to the t5p drivers with canare microphone cable.  All of the solder joints are clean and shiny, and I tested all of the connections with a volt meter prior to attaching the drivers.
 
So here are the questions:
1.  Is there any technical reasons that the t5p should do this running off the magni/modi?
2.  Is there any possibility that my re-cable job is responsible, since it works fine out of the logitech amp?
3.  Is there anything in particular that the failure mode points to?  The static pops when tapping the earcups seem very strange.
 
Any info would be greatly appreciated!  Thanks!

 

[hodgjy]

I believe in parsimony--the easiest answer is often the correct one.  The amp isn't causing those problems if those sounds aren't heard on other headphones.  Somehow your re-wiring project didn't go as planned and you messed up your headphones.

 

[morph2k4]

  I believe in parsimony--the easiest answer is often the correct one.  The amp isn't causing those problems if those sounds aren't heard on other headphones.  Somehow your re-wiring project didn't go as planned and you messed up your headphones.

 
Problem is, the re-cabled t5p works perfectly out of a different source powered to the same volume level.

 

[hodgjy]

You probably have a bad ground in the headphones.  I suspect the amps handle the grounding differently. 

 

[morph2k4]

  You probably have a bad ground in the headphones.  I suspect the amps handle the grounding differently. 

That's a good thought.  Is there any way I could go about checking this?  Both of the cups are doing the same thing, so whatever I did is probably the same on both sides.  Seems unlikely that I botched a joint in that case, but rather that my methodology was somehow wrong?

 

[hodgjy]

Without seeing the headphones, it's tough to say. But, I suspect you put on balanced connectors onto wires setup for a common ground.

 

[morph2k4]

  Without seeing the headphones, it's tough to say. But, I suspect you put on balanced connectors onto wires setup for a common ground.

How could the connectors on the headphones be fundamentally balanced?  I thought balance was just a function of using a balanced cable and a balanced source?  In all cases here, I am using the stock HD800 cable which uses a common ground.

 

[hodgjy]

  How could the connectors on the headphones be fundamentally balanced?  I thought balance was just a function of using a balanced cable and a balanced source?  In all cases here, I am using the stock HD800 cable which uses a common ground.

I worded my last post poorly.  If you used a stock HD800 cable with a common ground, I don't know what to tell you.  It's a strange result to have the static.

 

[morph2k4]

Well, I brought the t5p back to work today.  They work normally with my Valhalla 2.  It looks like the problem is isolated to t5p + magni.  I will try again with the custom cable when I finish it, rather than the stock HD800 cable.

 

[Rem0o]

  When I run the t5p through the stock HD800 cable into the magni/modi, I get tons of static in both earcups.  Additionally, tapping either ear cup makes a static pop sound from that ear. 

 
Tapping = static? There is something wrong with your recabling, one of your solder joint is maybe faulty/loose. 

 

[morph2k4]

It could be any of the joints to the hd800 jacks, since they are pretty small.  But, the tapping doesn't do anything on my Valhalla, or logitech amp.  Only the Magni.
 
I suppose I'll open it up and try to get a little bit cleaner joints on the pins, but I still don't understand why it would only happen with the magni.

 

[dsound]

  You probably have a bad ground in the headphones.  I suspect the amps handle the grounding differently. 

+1.   The T5p's are easy enough to disassemble to see if they are correctly wired.
 
Here's Zynsonix's picture of the wiring to the drivers (bare wire = ground in the pic)