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help with to wire headphones with speaker wire

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So, I have some hifiman he4xx headphones that utilize a 2.5mm jack per driver side. I want to power them with a low wattage speaker amp that uses tubes. I have not heard these be driven by a tube amp of any kind, so I am curious. The amp is a ZOTL 10 and sounds great on my Sierra 2EX speakers though a little more head room would be nice. SWo I found a TRS 2.5mm to bare wire adapter 4 pack on amazon, but thing is, the sleeve is packing 3 wires, which makes me wonder why the 2.5mm jack is TRS anyway.. wouldnt it only need to be a tip and a sleeve or is there a third wire for some odd reason? This makes little sense to me because the original cable terminates on the other end with a 3.5mm TRS jack.. which I have always know to be common ground (sleeve) and then the tip and the ring are the left and right positives. Could I just wire the jacks up pos and negative and forget about the third wire? If I can do this right this will sound pretty awesome considering I am running balanced line in XLR. Might be over kill for this pair of cans as they could be a bottle neck for such a nice amp. Any help would be appreciated.
 

Holmz

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Assume a wire for L+ and for R+, one would need a return wire… so the sums to 3 wires.
If the R- and L- were attached to a common ground at the amp, then 3 would be the number to use.
Like a TRS.

However if R- and L- are also pushing/pulling then you would need 4 wires and TRRS.

Since the headphone have one cable per side, then the shield of the cable could be tied to ground, and the +/- would go to the headphones.

I do not know if it is ring or sleeve that would carry the grounded shield.
Or maybe I do…: https://pinoutguide.com/Audio-Video-Hardware/Tele35s_pinout.shtml
 

solderdude

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which makes me wonder why the 2.5mm jack is TRS anyway.. wouldnt it only need to be a tip and a sleeve or is there a third wire for some odd reason?

Only tip and sleeve is used (on both sides) in the HE400.
In theory one could use 2.5 TS but in practice this can cause issues when plugging and unplugging the cups with an amp active.
The ring is not connected to ensure that when pulling the plug from the headphone the connected amp is not accidentally shorted.
So when using prefab TRS simply do not connect the wire going to the ring.
 

restorer-john

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From the brief look at online pics, that amp appear to have direct connected tubes (no transformers). I don't know, but I'd be very careful with any common ground (TRS) connecting. One pair of wires to each cup direct.

Voltages on tubes can be pretty high- be careful if the amp is indeed unusual.
 
OP
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Only tip and sleeve is used (on both sides) in the HE400.
In theory one could use 2.5 TS but in practice this can cause issues when plugging and unplugging the cups with an amp active.
The ring is not connected to ensure that when pulling the plug from the headphone the connected amp is not accidentally shorted.
So when using prefab TRS simply do not connect the wire going to the ring.
This explains a lot. Thanks for the info. when I make the wires I will put a lil dab of hot glue on wire not used and apply heat shrink tube to both wires with a larger one over all three and apply banana plugs to the bare end that connects into the terminals on the amp. I will treat it like any tube amp and always have everything connected and ready to go with turning the power on as the final step before listening. I guess I really need to figure out if the volume control is Logarithmic in nature, as a final consideration for this. One last thing, in terms of protecting the amp as you mentioned, if a headphone driver is unplugged do you think the extra caution of powering down the amp would be advised?

Edit, I wrote about using the tone control delete input but figured out after looking in the back its only an option for RCA inputs, so I will be going with RCA to 2.5mm TRRS at the Fiio end. Wasnt sure how fast you would see the response so I removed it and added edit.
 
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solderdude

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if a headphone driver is unplugged do you think the extra caution of powering down the amp would be advised?

No need for that. Some tube amps, however, don't like to see no load. Most tube amps have no issues with that though.
Turning down the volume or switching off the amp won't hurt.

When the RCA on the amp are internally connected you cannot connect a 2.5mm TRRS balanced output to it.
 
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