Then you must have either damaged something or made a mistake in the wiring. Electrically, any half-decent 2 cond + shield will do. Parasitic resistance and capacitance are non-factors, unless you make 300 ft cables.Whoops said:
Heaphones replacement cable - What cable to use?
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scott2000
Well-known member
abbey road d enfer said:
I should've been clearer. I wasn't speaking of headphone cables but using 2 conductor for unbalanced interconnects..... 2 conductors 1 shield...... tying shield to ground at one end only...
abbey road d enfer said:
No I haven't
and I can guarantee that 2 twisted conductors wrapped in shield (like microphone cable) for this aplication sounds worse than 4 conductors (not twisted and no shield) like the original headphone cables
Can you measure it?Whoops said:
abbey road d enfer said:
Will try to Abbey,
just need some free time and get a setup in the workshop
thanks
trashcanman
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pucho812 said:
I did it to a pair of DT 990s and just ran the two conductors that I needed to the other side. There were no pcbs inside, just the drivers.
pucho812
Well-known member
trashcanman said:
Oh ok, so you stripped of the jacket
benb said:
Can you give a technical explanation of why all headphone cables have no shield and use 4 conductors that are side by side and not twisted?
microphone cable is completly diferent, that was explained before. It's 2 conductors and not 4, the 2 conductors are twisted and are wrapped in shield.
Gene Pink
Well-known member
benb said:
With a common return (the shield), the voltage drop from one side being driven, shows up faintly in the other side, but in reverse polarity. Not much, depending on headphone Z, but could be enough to screw with any stereo imaging. Worse with lower Z phones, Radio Shack made 8 ohm ones.
Separate (-) returns prevents this.
Gene
You make a description, but don't explain why...Whoops said:
And what you describe is not universally true; there are many other types of cables used on headphones. Because you haven't seen them does not mean they don't exist.
Gene Pink said:With a common return (the shield), the voltage drop from one side being driven, shows up faintly in the other side, but in reverse polarity. Not much, depending on headphone Z, but could be enough to screw with any stereo imaging. Worse with lower Z phones, Radio Shack made 8 ohm ones.
Separate (-) returns prevents this.
Gene
yes definitely,
that I think is one of the reasons
abbey road d enfer said:
I don't know why, but Im learning.
The reason I made this thread is so that we can all discuss this and so that people with more knowledge than me can chime in and hopefully explain the situation technically.
All the headphones I've repaired (7 to 8 pairs) had 4 conductors (not twisted and no shield), I still have to find one pair that has shield or twisted conductors.
I'm sure there's a technical reason for that.
Gene Pink gave one of the reasons
And I'm sure now, after trying different cables that using microphone cable is not the best for this purpose.
I'm gratefull that you gave your opinion and thoughts, but I don't think you are correct and I wish more people can join and discuss this
thank you
That is true, however the contact resistance of the jack's sleeve is higher than the shield resistance of a decent mic cable. I agree that using a 3-conductor wire of very thin gauge is subject to this problem.Gene Pink said:With a common return (the shield), the voltage drop from one side being driven, shows up faintly in the other side, but in reverse polarity. Not much, depending on headphone Z, but could be enough to screw with any stereo imaging. Worse with lower Z phones, Radio Shack made 8 ohm ones.
musika
Well-known member
I agree, I looked for quite a while before I settled for the Mogami W2893 which has the smallest overall diameter I could find.
scott2000
Well-known member
I wonder if tonearm wire could work??? I'd imagine their could be a bunch of contact noise with some??? I've had issues with solid silver wire in this.....I saw a mention of CAT5 being used too.....
Microphone cable needs to be shielded, because the signal is low-level (Typically 1pW-1uW) at a moderate impedance of 150-600 ohms. Conductors are twisted because that reduces the risk of RFI/RMI interference.Whoops said:
That is not necessary for headphones cable, because the signal level is much higher (typically 1-100 mW) and headphones are inherently immune to RFI/EMI.
Before headphones became a fashion statement, headphones manufacturers would look to make the cable robust and provide adequate performance,which is not a challenge at all.
Now that headphones are to be worn as ornaments, manufacturers had to make the cable as unconspicuous as possible, i.e. thinner and thinner, so now the conductor's resistance is high (very thin wire) and thus the common return must be replaced with separate returns, in order to avoid the out-of-phase effect (that does not affect frequency response as much as the stereo imaging). Since they don't need to be twisted, laying them untwisted is correct.
So one of the reasons for not unsing Mic cable is found, the need for individual return paths.
I have 2 questions also in case you can answer,
How would the 2 conductors being twisted could affect capacitance relative no not twisted?
How could the 2 conductors being wrapped in shield that is connected to the return path could affect the capacitance compare to conductors that have no shield wrapped?
I have 2 questions also in case you can answer,
How would the 2 conductors being twisted could affect capacitance relative no not twisted?
How could the 2 conductors being wrapped in shield that is connected to the return path could affect the capacitance compare to conductors that have no shield wrapped?
We are talking here of effects that are at least 80 dB below signal. In fact with "normal" stereo program, that is in fact about 80% mono, the effect is nil because the two out-of-phase signals compensate each other, resulting in a negligible signal loss (about 1/100th of a dB).Whoops said:
Not more than 10%. Residual inductance may also vary.
Close to twice.
However, the capacitance of a mic cable is about 150pF for a 5 ft cable, resulting in a -3dB BW of 30 MHz (0.0001dB at 20 kHz) for a 32 ohm headphone.
Thanks Abbey,
those are already good enough reasons to not use mic cable for this aplication,
but what I listen is more than that.
I will do some measurments in the near future, I think the effects of not having individual return paths might be more than that.
Thank you once again
those are already good enough reasons to not use mic cable for this aplication,
but what I listen is more than that.
I will do some measurments in the near future, I think the effects of not having individual return paths might be more than that.
Thank you once again
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