Quote:
Originally Posted by spendorspain /img/forum/go_quote.gif
Hi,
I too have a doubt regarding the connection of headphones using 4-pin XLR connectors and not the standard “TRS” phone stereo plug. According what I have read in the internet, a good XLR plug is a better connector than a standard TRS. I have a Grado HP-2 recabled with Moon Silver Dragon cable with a standard 1/4inch phone plug and, in the other end, directly hardwired to the drivers. Its 4 conductors are braided all together (not in two pairs) and encased in a common jacket, so perhaps I have a problem because I can’t find out what is the ground cable for each channel. If I open the ¼” connector, I’ll see one clear wire soldered to the tip of plug (left signal), other clear wire soldered to the ring (right signal) and two white wires soldered to the plug “sleeve” (common ground), but, as the 4 wires all go together into the cable “jacket”, I have no mean of knowing what of these white wires is the “left ground” and what is the “right ground” for correct soldering in the 4-pin XLR connector with separate grounds (however, I could clearly identify the “live” L and R wires looking at the part of the standard TRS plug they are soldered to and marking them before desoldering… my doubt is only the two “ground” wires).
However, perhaps this is of no importance. My amplifier is a two-channel single-ended (left and right inputs via RCA sockets), not balanced, and I think maybe it doesn’t matter what is the “left” ground and the “right” ground because, anyway, they will be joined at the “ground” pin of the ¼” output socket in the standard connection. The use of a 4-pin XLR will split this sole ground connection in two, but I’m wondering if in an unbalanced design (be a dual mono with independent power supplies or not) it is irrelevant what ground wire goes to each channel.
It is possible that in the new 4-pin XLR headphone plug the L ground and the R ground be reversed, so the “left signal” wire and the “right ground” wire will go to the left driver (and the “right signal” and the “left ground” to the right driver). Doing this, I’ll mix L and R channel grounds but, as they both are the same in an unbalanced amplifier, perhaps there will be no problem. Is this a problem? What is your advice on this?. I apologize if this question is a little dumb, but if I’m not sure about it, I’ll have to use a standard TRS connector and not the better sounding XLR.
Thank you for your help
Best regards
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i would be EXCEPTIONALLY carefull with this.
if the left and right chanels are "mixed" in a 4-pin conector there may be some very bad results from a balanced amp. weird phase cancelations, generally poor performance, and the like are all possible. with a single ended amp, there is no real difference BUT if you are going to go through the trouble of reterminating these, keep the wires straight! at some point you will want to plug into a balanced amp, and then you will have all sorts of issues if you are careless now.
you can see what goes where with a multimeter.
if you are "absolute phase" sensative, then i would check how they are wired now aganst the ground. hold one end of the DMM on the ground of the trs, and the other end probe the pads on the drivers. when looking at the back of the driver, with the solderpads at 3 oclock, one is top, and one is bottom. be sure to get relative phase corect. this is VERY important.
after this, it is a simple matter to reterminate in a 4-pin.
btw, my hp2's also have a 4-pin. mikhail was impressed and commented on how much money he would save if EVERYTHING had a 4-pin. he could have saved 2 jacks on his balanced ppx3 (which was why i put that conector on.)
i am not "absolute phase" sensative, and when i got my hp2's they were reterminated with a WORTHLESS radioshack 1/8" plug so im not really sure which pad is + or -. they are relative phase correct, and sound very good from the ppx3 balanced.
after i wrote ALL of that, i went back to quote grandenigma, and realised that the quoted passage was written 6 months ago. poo. maybe it will help someone else.
