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Rowdy

Balanced Headphone Jacks

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Hi all, I got a Max Headroom amp with balanced connections sitting around. Anyone can tell me the benefits of balanced vs the normal headphone jacks? Should I re-cable my new SR325s to balanced to take advantage of this? :helpsmilie: Xtreme newbie here, thanks!

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Headroom gives a nice, easy-to-understand run-through:

Standard headphones have three electrical connections: one to each ear and a common ground wire. The audio drive signal goes to one side of the driver coil in each earpiece, and the return from the coils joins together in the common ground connection. In balanced headphones both sides of the driver coil are driven simultaneously and no common connection between channels exists. Therefore, balanced headphone amplifiers generate a normal and a perfectly inverted audio signal. The inverted signal is basically a mirror image of the normal drive signal; so when the 'normal' signal is going positive, the inverted signal is going negative in an identical sine-wave relationship. In brief, this complex method of driving headphones effectively doubles slew rate, voltage swing, & power output, and halves the output impedance of the amp as seen by the headphones. The result is a dramatic improvement in audio quickness, musical clarity, and sonic impact.

 

I also believe balanced connections are basically immune to RF interference.

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Thanks. Now the problem is if I do re-terminate, I cannot use my SR325s with my portable setup anymore! Another thing, if by re-terminating, would the Grados benefit from any other types of cables? And if so, what types and who can do the re-cabling?

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Headroom gives a nice, easy-to-understand run-through:

Standard headphones have three electrical connections: one to each ear and a common ground wire. The audio drive signal goes to one side of the driver coil in each earpiece, and the return from the coils joins together in the common ground connection. In balanced headphones both sides of the driver coil are driven simultaneously and no common connection between channels exists. Therefore, balanced headphone amplifiers generate a normal and a perfectly inverted audio signal. The inverted signal is basically a mirror image of the normal drive signal; so when the 'normal' signal is going positive, the inverted signal is going negative in an identical sine-wave relationship. In brief, this complex method of driving headphones effectively doubles slew rate, voltage swing, & power output, and halves the output impedance of the amp as seen by the headphones. The result is a dramatic improvement in audio quickness, musical clarity, and sonic impact.

 

I also believe balanced connections are basically immune to RF interference.

 

 

i still don't understand. lol :rclxub:

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Take a little time to read up on 'Balanced Impedance' in Wikipedia.com

You might have a better understanding on benefits of balanced headphones.

 

Milkpowder is right about minimal RF interference:

The balanced impedances to ground minimizes interference pickup. The conductors are sometimes twisted together to ensure that each conductor is equally exposed to any external magnetic fields that would induce unwanted noise. The line is capable of being operated in such a way that when the impedances of the two conductors at all transverse planes are equal in magnitude and opposite in polarity with respect to ground, the currents in the two conductors are equal in magnitude and opposite in direction.
Extracted from Wikipedia.com

 

 

Edited by zonalblitz_audio

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Wikipedia has a decent explanation too. I also thought this was pretty informative: http://www.6moons.com/audioreviews/balance...phones/one.html

 

Thanks. Now the problem is if I do re-terminate, I cannot use my SR325s with my portable setup anymore! Another thing, if by re-terminating, would the Grados benefit from any other types of cables? And if so, what types and who can do the re-cabling?

 

I have never ever tried balanced Grados nor recabled ones. Quite a few companies will recable your Grados though: Moon Audio, APureSound, Headphile, etc. The stock Grado cable is a decent OFC so the benefits of recabling it is questionable. Maybe it could use higher purity conductors, different materials (OCC copper, silver, gold, or even carbon fibre), better insulation, etc, but who knows whether the sound signature will change for the better or worse? Unfortunately, my lack of experience in this area means that I can't offer any solid advice. <_<

 

If i am not mistaken, going balanced would also require your source to be balanced. this would then maximise the benefits of having balanced headphones.

I've read that too, but I really question whether it would really make a huge difference. A lot of cheap so-called balanced sources aren't really utilising fully balanced internal circuits anyway (balanced output signal converted from single ended signal through the use of either a transformer or phase splitter circuit).

 

I'll refer to what Tyll Hertsens of Headroom Corporation said about balanced drive:

 

Many pre-amps that have bothe balanced and unbalanced inputs and outputs contain a phase splitter. This circuit is designed to take an unbalanced signal and make it balanced. A tranformer could be used here, but more commonly a phase splitter circuit is used. This circuit contains at its heart an inverting amplifier that takes the unbalanced signal and inverts it to make up the "-" signal. The problem is that the normal non-inverted signal does not pass through this amp. What happend is that the inverted "copy" of the normal signal is slightly different because it has passed through the inverting amp. When we're talking about achieving high levels of performance with this technique, ANY missmatch between the two signals is a definate no-no. Many of the very competent technical arguments against balanced drive (PPLs for example) contain a disgust for using this "phase splitter"---a disgust which I share.

 

I believe there is only one way to do balanced right which is by starting with a balnced signal and then keeping them perfectly matched (as humanly possible) through-out the entire signal chain. The only way I know of to do this is: getting a signal from both sides of the coil in a phono cartridge, microphone, ot tape head, and by having two digital to analog converters for each of the left and right channels one outputting the normal signal and the other a numerically perfect inverted signal. ANY other method for creating a balanced signal for a single unbalanced signal will create a non-perfect copy, and therefore significantly minimize the benefits of balanced drive.

Edited by milkpowder

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Thanks. Now the problem is if I do re-terminate, I cannot use my SR325s with my portable setup anymore! Another thing, if by re-terminating, would the Grados benefit from any other types of cables? And if so, what types and who can do the re-cabling?

 

Be careful about a simple re-termination. For the Audio-Technica headphones this will not work. You will need to go all the way into the ear cups with new cable. The ground wire is shared along the cable length with these headphones.

 

 

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To truly benefit from a balanced system, it is important to maintain a true balanced signal all the way from the source to the amp to the headphone. As Milkpowder pointed out, not all sources that claim to have balanced outputs truly do. Those that I know have true balanced outputs include Meridian G08, Marantz SA11S1 and Cambridge Audio 840. Buyer beware!

 

I have no scientific explanation why a balanced set up should sound better but my (admittedly limited) personal experience has made me a believer. :thumbup:

 

Even when level matched, I find the balanced outputs to be more spacious, have better seperation and tight control over the bass.

 

I have 'balanced' my Sennheisers (HD580/600/650) and have found appreciable improvements across all, with the HD650s benefitting the most from going balanced.

 

As with all things audio, the cost of going balanced raises the price quite a bit and the differences/improvements are not night and day.

 

From my understanding, Grados cannot simply be reterminated into a balanced setup using the original cable. A total recable is necessary. It also appears that Grados do not seem to benefit greatly from balancing. YMMV.

 

Should you decide to reterminate your cans with balanced XLR connectors, it is also possible to make an adaptor (female XLR -> 1/8" plug) that will allow single-ended use. Heavier and clumsier, but definitely possible. :grin: Will try to post some pictures tonight.

Edited by tbln

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Hmmm, maybe I'll leave my Grados alone then. Perhaps look for an old HD650 to re-terminate... Then again, what Tyll Hertsens of Headroom Corporation said may be true. If so, my Max Headroom may have some problems as I am using a Naim CDX as source. This means the signal will go from DIN to phono to balanced! This may really screw it up! :think:

Anyone got balanced cans to loan me to prove this theory? :grin: I can attempt to write a review after that...

 

Edited by Rowdy

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