[GUIDE] Balanced AKG K702 with detachable 4-pin mini-XLR cable
Jan 18, 2013 at 3:24 PM Post #31 of 67
Ahhhh, I understand. So I need to test every connection while shooting power threw 1 conductor to ensure the others are separate
 
Jan 18, 2013 at 5:03 PM Post #32 of 67
Yes there are many ways you can accidently short pins while making a cable.
 
The easy way to test it is to plug the cable into the headphone, and then test the continuity between the "pins" on the TRS connector. It should look something like this:
 
TRS+jack.jpg

 
Between TIP and RING ~120 Ohms
 
Between TIP and SLEEVE ~60 Ohms
 
Between RING and SLEEVE ~60 Ohms
 
If one of those shows 0 Ohms, you have a short. If one of those is infinity, you have an open circuit.
 
Have fun. 
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May 10, 2013 at 12:59 PM Post #33 of 67
Seeing as you replaced the cable for balanced use, does it not matter that the ricght driver will have a longer cable due to the fact that it's a onesided output?  If you were to rewire the phones with a better quality cable either cardas or silver or something, then would it be necessary to also rewire from the input jack to the left and the right cups?  I hope that makes sense lol, I'm planning on buying a pair of the q701's which have a similar setup and would like to experiment with some different cable setups for it!
 
Thanks!
 
May 11, 2013 at 11:05 AM Post #34 of 67
Well, if you believe dual entry is inherently better, then you'll probably hear a difference. Otherwise, no, it's not a problem. 
 
The main advantages of balanced cabling are still there, even if one side goes trough the headband. It would, in theory, raise the impedance of the cable for this driver. In practice, I bet the difference would be smaller than the variance in impedance due to soldering. In other words, you may find the same variance even in a dual entry cable, simply because the solder joints are not perfect and introduce resistance which may be different from one to the next.
 
May 11, 2013 at 12:49 PM Post #35 of 67
Just to make sure that I understand what you're saying: So even if I wanted to upgrade to a silver cable, on a single entry style headphone, rewiring from entry point to the other driver wouldn't be necessary?  Wouldn't that change the sound from source to far cup due to the different cables?  I am quite naive when it comes to recabling, so I just want to make sure that I do it right :)
 
May 11, 2013 at 4:06 PM Post #36 of 67
Just to make sure that I understand what you're saying: So even if I wanted to upgrade to a silver cable, on a single entry style headphone, rewiring from entry point to the other driver wouldn't be necessary?  Wouldn't that change the sound from source to far cup due to the different cables?  I am quite naive when it comes to recabling, so I just want to make sure that I do it right :)


In theory the advantage of dual entry is that you avoid the wire through the headband that MIT be low quality. In truth, that wire is small, and is pretty good quality on most headphones, that it doesn't really matter.

I have a balanced Q701, single entry, sounds great. Balancing a headphone simply is separating the grounds, so you can have inverse signals.
 
May 12, 2013 at 1:14 PM Post #37 of 67
Though with AKG headphone, it is interesting. The two metal rods making the headband are used to carry signal from one cup to the other. These rods are probably made of a metal alloy chosen for its physical properties, not electrical ones. Then there are small wires soldered to the ends of the rods. So in practice, the right driver's signal has to go trough 4 additional solder joints and long metal rods. It may be interesting to measure the total impedance of this system. It may be significant. 
 
May 12, 2013 at 1:37 PM Post #38 of 67
Quote:
Though with AKG headphone, it is interesting. The two metal rods making the headband are used to carry signal from one cup to the other. These rods are probably made of a metal alloy chosen for its physical properties, not electrical ones. Then there are small wires soldered to the ends of the rods. So in practice, the right driver's signal has to go trough 4 additional solder joints and long metal rods. It may be interesting to measure the total impedance of this system. It may be significant. 


I thought there is a wire straight from the left driver to the right driver, no intermediate wire/pole. I could be wrong though
 
May 26, 2013 at 12:05 AM Post #42 of 67
yea don't think the metal rods could be that much of a problem or there would already be significant left/right imbalance in the sound right? AKG probably considered that??
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just got my k702 annies... considering a possible future with balanced
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May 30, 2013 at 11:53 AM Post #43 of 67
I am not sure it is fully balanced when you only have one cable coming out of one side~~~
I think a Y split will be a better idea here cause different length and material of the wire will lead to different resistance. If you care that much to turn the AKG into a balance setup, the last thing you will want is the channel imbalance caused by different wire resistance.
 
P.S.
The cable looks very nice!
 
May 30, 2013 at 2:45 PM Post #44 of 67
Quote:
I am not sure it is fully balanced when you only have one cable coming out of one side~~~
I think a Y split will be a better idea here cause different length and material of the wire will lead to different resistance. If you care that much to turn the AKG into a balance setup, the last thing you will want is the channel imbalance caused by different wire resistance.
 
P.S.
The cable looks very nice!

 
But how would you get it to Y split?, you'd have to drill a hole on the right side no? or would you order another left piece enclosure and hope it fits on the right side? can you even order that part? if so... where???? =)
 
P.S. if going with a Y split would you have to somehow disconnect the connecting rods? wouldn't it possibly cause short circuit? Sorry if these are stupid questions... i'm a noob... not an electrical engineer
 
May 30, 2013 at 2:50 PM Post #45 of 67
I think the cups are interchangeable, so you could probably put the left cup with the 3-pin mini-XLR onto the right side and do a y-split.
 
As for where to order the cups, I think I just went to their website and found a number to call. There's no online store for parts AFAIK. There's also the service manual with the part numbers somewhere but I forget where I found that. This was all a couple years ago...
 

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