[Akathriel]

There is one other reason, to use 2x3 pin. Correct me if Im wrong but if your headphone cable is shielded, you could connect the drain wire to the ground of the amp.

 

[Blueiz]

Because they look so damn cool.....

 

[grawk]

TRS connectors are used in low end pro gear because the connectors are cheaper, and they're high density.

 

[Sovkiller]

Quote:

Originally Posted by TreAdidas /img/forum/go_quote.gif According to Headroom's Tyll at the LA and Orange County Audio Society Meet. They made the first balanced headphone amplifier and the reason they used the XLR type connectors was because Neutrik makes a combo 3-pin XLR and 1/4" plug chassis jack. That makes it convenient to do both balanced and single ended in just two chassis points. From http://www.neutrik.com/us/en/lightin...oductlist.aspx "First XLR / jack hybrid panel mount connector combining a 3 pole XLR receptacle and mono or stereo ¼" phone jack in one XLR housing."

IIRC the 1/4 plug inside the XLR is mono, so it could not be used in a SE configuration, i do not see how at least, you have to bring the other amp into the mix of that XLR and is a mess then, but it could be used by another heapdhone balanced with two mono 1/4 plugs instead of XLR though, in case you happen to have one...I personally like better the 1/4 for heapdhones than the the XLR...but the world has adopted the XLR...

About the surface contact, well in the pin of the XLR the surface is really minimal, tiny, not sure how it could be better than a good 1/4 jack..

I think that is more for the shorting issue, that is why some manufactueers place resistors at the output in series to avoid that, and always have a load there on the amp...also you can do a dualmono heapdhone instead of balanced using 1/4, using one for each channel in a similar way...

 

[sugarinthegourd]

Thanks for the helpful replies folks. I thought there were only 4 wires involved & am glad to know it's not me missing something -- though the shorting aspect of the 1/4" plugs is not something I had thought about in this context (though I had thought about it in others).

 

[jp11801]

actually my understanding of this is that headroom was at the begining stages of this and their amp was a dual monoi config so they simply used the 3 pin xlr like the current source and amp convention at the time. In hindsight the 4pin would have been a hell of alot easier but ...

 

[nikongod]

Quote:

Originally Posted by MaloS /img/forum/go_quote.gif Ya but we tend to connect our system before we even turn it on so that does not really matter.

not i said the fly. "watch" the turn on spikes from a decent OTL tube amp. yea, high voltage like whoa. you seriously dont want anything to do with this. dont think your imune with a SS amp because it cant even swing 50V into a load. SS amps can put current in, and if they have a fault (say a really slow DC servo) they can cook something...
Quote:

Also TRS is fairly standard in quite a bit of professional systems I've seen. Generally more comfortable >.< I get constantly bothered by how big XLR is, when electronically having pair of mini-plugs is as good as pair of 3-pin XLRs..hell, a pair of mono mini-plugs is just as functional (you only need in and out pins, which can be easily substituted by + and ground points of a mono mini-plug).

TRS is a standard audio connector as a throwback to the ORIGINAL phone systems. the whole point of the TRS system was that it could be switched quickly with one hand. in virtually every other aspect, XLR is a superior connection system. xlr plugs have NO contact issues with a heavy plug/cheap jack and xlr will never short the outputs.

compare the actual size of a 4-pinxlr to a similarly constructed TRS plug. the neutrik 4-pin occupies the same "panel space" as 1 trs, and the XLR although fatter is shorter in total length. i vote for the XLR. ont eh subject of balanced connectors, i terminate my headphones with 4-pin, and use an adapter when connecting to an amp made by someone who only puts 3-pins on...

 

[bhd812]

the correct reason why XLR connectors are used is...

The majority of Balanced setups in the world use XLR's are pro audio (recording, concerts, pa, etc) where true Balanced audio is not a luxury but a must. people in these industries use XLR plugs (and have since the dawn of time) cause the connectors and plugs themselves are very Heavy duty and less prone to problems like 1/4 connectors and jacks (try to rip a wire/cable out of a neutrik connector) are AND because everyone else is..

this is Where Headphone amps began to use XLR's also, just because everyone before always used the commonly common XLR for the outputs and inputs. balance cd players have XLR outs so it only makes sense to use XLR for the headphone connection also.

there is also spin offs in the same industries using XLR plugs like Microphones, and DMX-512 lighting (XLR plug on data cable for data connections).

there is lots of other connectors used like 5 pin xlr but not as common..

 

[CarbonTi]

Well, the only XLR oddity in the headphone world is the convention of using a male connector on the headphone. The standard convention is that outputs in balanced configs accept a female XLR so the headphone male XLR connector is travelling to beat of a different drum.

 

[grawk]

Quote:

Originally Posted by Sovkiller /img/forum/go_quote.gif IIRC the 1/4 plug inside the XLR is mono

You don't remember correctly.

 

[krmathis]

You talk about balanced signal between source and amplifier, right?
Then XLR is used because there are three cables to connect.
* Chassis ground (cable shield)
* Normal polarity ("hot")
* Inverted polarity ("cold")

http://en.wikipedia.org/wiki/Balanced_audio
http://en.wikipedia.org/wiki/XLR

 

[Kees]

Quote:

Originally Posted by swt61 /img/forum/go_quote.gif Nice solution grawk.

X2. Well thought out.

 

[Kees]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif You talk about balanced signal between source and amplifier, right? Then XLR is used because there are three cables to connect. * Chassis ground (cable shield) * Normal polarity ("hot") * Inverted polarity ("cold") http://en.wikipedia.org/wiki/Balanced_audio http://en.wikipedia.org/wiki/XLR

No, I understand he is talking about balanced headphone cables, which means there are only two cables to connect.

 

[mofonyx]

I agree with krmathis.

The third pin is wired to the cable shield.

 

[Kees]

Quote:

Originally Posted by mofonyx /img/forum/go_quote.gif I agree with krmathis. The third pin is wired to the cable shield.

there is no cable shield in a headphone cable. We're not talking about inter connects here....