Hello All,
I have not ever held in my hand a set of balanced headphone cables. I have seen and read that they can cost a lot. I do not want to pay more for the cable than the Eletra-Print Audio balanced output transformers. My goal is the most fidelity for the buck, euro whatever. The tubes were $ 0.35 each.
Is there an industry standard plug? Separate plug for left and right? Or a single plug for both? Locking din, XLR or TRS? Metal or plastic? The amplifier output will be built to match.
At the headphone end of the cable are those plugs proprietary or can they be purchased from Digikey or where ever? Or clipped off a factory replacement cable?
The cable itself is it a separate shielded cable for each ear or what? If both ears are inside a single shielded cable will there be cross talk? Silver plated is in the budget. Solid silver is too rich.
Thanks
DT
I have not ever held in my hand a set of balanced headphone cables. I have seen and read that they can cost a lot. I do not want to pay more for the cable than the Eletra-Print Audio balanced output transformers. My goal is the most fidelity for the buck, euro whatever. The tubes were $ 0.35 each.
Is there an industry standard plug? Separate plug for left and right? Or a single plug for both? Locking din, XLR or TRS? Metal or plastic? The amplifier output will be built to match.
At the headphone end of the cable are those plugs proprietary or can they be purchased from Digikey or where ever? Or clipped off a factory replacement cable?
The cable itself is it a separate shielded cable for each ear or what? If both ears are inside a single shielded cable will there be cross talk? Silver plated is in the budget. Solid silver is too rich.
Thanks
DT
Nope.
I think dual three pin XLRs is the most retarded thing ever cooked up. It's popular, no thanks to Headroom, but no one actually likes it. A single XLR is bad enough. But really, who wants two big goat testicles dangling from their headphone cable?
That's what I would recommend.
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Mini XLR is a good choice unless you're using 18 gauge wire for your headphone cable.
Flip a coin.
Which headphones?
Most headphones have the cable wired directly into them. Sennheiser uses two different types of connector, one on their HD-580's, 600's and the like, and a new one on their HD-800's. Cardas makes aftermarket connectors for the former, and I can't recall off the top of my head who's selling the latter. Just Google "hd-800 connector."
Can be depending on who makes it. Personally I don't see any need for shielding.
Some. Whether it's meaningful is arguable.
se
Double 3 pole XLRs are an unfortunate hangover from HeadRoom promoting it for their own benefit.
A miniature 4-pole connector would be neat at the amp end of the cable, but would restrict you to your own amp because other amps are unlikely to ever have a matching connector. A single 'normal size' 4 pole XLR would be very sensible as this is likely to become some form of unofficial standard in the market methinks.
Personally, I would go for metal shell. (Objectively more sturdy to cope with insertion / extraction. Subjectively feels more positive to the hand and looks more professional to the eye).
Shielding works as sheilding (yes, really). It's also a real-world advantage when smaller gauge conductor wires are used, as it helps add strength to flimsy cables.
A miniature 4-pole connector would be neat at the amp end of the cable, but would restrict you to your own amp because other amps are unlikely to ever have a matching connector. A single 'normal size' 4 pole XLR would be very sensible as this is likely to become some form of unofficial standard in the market methinks.
Personally, I would go for metal shell. (Objectively more sturdy to cope with insertion / extraction. Subjectively feels more positive to the hand and looks more professional to the eye).
Shielding works as sheilding (yes, really). It's also a real-world advantage when smaller gauge conductor wires are used, as it helps add strength to flimsy cables.
Yes.
From what I understand, when they first started messing around with "balanced" headphone amps ("bridged" is a more meaningful term to describe what Headroom promotes as "balanced") they used two separate stereo amplifiers with their channels bridged. So with two physically separate amps, you needed to physically separate connectors.
The problem is that when they started making "balanced" amps in a single chassis, instead of switching to a single connector, they kept the dual three pin XLR's.
Stupid.
Yes. I think a four pin XLR is an ok compromise.
I think it's overrated. Especially for headphones (the voice coil makes a nice antenna). About all it really does is add more capacitance.
Then don't use flimsy cables.
se
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Ray Samuels is pushing a Kobiconn micro 4-pin camera iris control connector for IEMs:
The RSA Protector balanced portable: Images and impressions 1st page, Please post your impressions . . - Page 4 - Head-Fi: Covering Headphones, Earphones and Portable Audio
Lemos look nice too
the totally insane could use 8 pin connectors - Kelvin force/sense for each wire of the headphone cable - no contact resistance worries
extend to the drivers? - I've closed >100KHz gain intercept frequency feedback loops over 100' of twisted pair in strain gage transducer amps
wonder what the cable fetishists would have to say about that
The RSA Protector balanced portable: Images and impressions 1st page, Please post your impressions . . - Page 4 - Head-Fi: Covering Headphones, Earphones and Portable Audio
Lemos look nice too
the totally insane could use 8 pin connectors - Kelvin force/sense for each wire of the headphone cable - no contact resistance worries
extend to the drivers? - I've closed >100KHz gain intercept frequency feedback loops over 100' of twisted pair in strain gage transducer amps
wonder what the cable fetishists would have to say about that
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Hello All,
Thanks for the output guys and se it looks like you are a neighbor.
Sounds like nothing is cast in concrete. The first effort will be the parts that I can find in the old library card index where I store things. I have some milspec silver plated wire I will braid up, ooh pretty colors.
Thinking of cables, the TRS output at the typical amplifier has a common ground. The ground is common to both output transformers. A replacement set of headphone cables need not share a single return path, each ear can have a separate ground all the way back to the output jack that by its self may be a good start towards determining if HeadRoom really made all this stuff up.
DT
All just for fun!
Thanks for the output guys and se it looks like you are a neighbor.
Sounds like nothing is cast in concrete. The first effort will be the parts that I can find in the old library card index where I store things. I have some milspec silver plated wire I will braid up, ooh pretty colors.
Thinking of cables, the TRS output at the typical amplifier has a common ground. The ground is common to both output transformers. A replacement set of headphone cables need not share a single return path, each ear can have a separate ground all the way back to the output jack that by its self may be a good start towards determining if HeadRoom really made all this stuff up.
DT
All just for fun!
How would you know? *closes all his drapes*
Cool! You have one of those too? I have a nice one in maple made by Remmington Rand back in the 50s. Hiram Johnson high school was getting rid of theirs because their indexing on computer and my mother was a custodian there so I was able to get one.
As a side note, I think it's a bad idea to eliminate the card catalogs. Some years back I went over to the library and all the terminals were down. Apparently a work crew had dug up some phone lines in the area.
So I asked the librarian where the card catalog was.
"Oh, we got rid of those."
*sigh*
Just as there's still something to be said for dual triodes, there's still something to be said for good ol' ink on paper.
Far out, man! Hmmm. No "trippin" smiley. Just use your imagination.
Yeah, but that's not going to address the biggest "problem" which is the common contact resistance of the TRS.
That's the spirit!
se
If you are DIY'ing your amps, then I'd also agree that the 4-pin XLR is a great jack and plug combo to use. The mini-XLR version is becoming very popular on single entry headphones like AKG and the new Audeze LCD-2 uses them on each ear cup. The 4-pin mini-XLR would be a good candidate for a balanced portable amp, especially if you designed it with THAT ICs to split the SE input into balanced. Adapters aren't hard to make either.
The other issue with TRS is that they short when inserting and disconnecting, so you have to account and protect for that with you builds. Many a Beta22 amp has been sent up in smoke because somebody forgot to turn it off before removing the headphones... My F5 will have resistors on the TRS jack to keep the short from blowing the outputs, if I even bother putting a TRS jack on it.
I love the MIL-SPEC Alpha brand stranded SPC. Eight 28awg wires per cable, 4 per channel, is a really nice, durable cable.
All of my cables are being reterminated to 4-pin XLRs. I'm making an adapter box to allow my cables and headphones to run off any amp though, whether it's a SE 1/4" TRS or dual 3-pin XLRs. Flip side is also being addressed, any other cable termination can be adapted to my amps. Actually considering using my balanced TPA Darwin for this role.
The other issue with TRS is that they short when inserting and disconnecting, so you have to account and protect for that with you builds. Many a Beta22 amp has been sent up in smoke because somebody forgot to turn it off before removing the headphones... My F5 will have resistors on the TRS jack to keep the short from blowing the outputs, if I even bother putting a TRS jack on it.
I love the MIL-SPEC Alpha brand stranded SPC. Eight 28awg wires per cable, 4 per channel, is a really nice, durable cable.
All of my cables are being reterminated to 4-pin XLRs. I'm making an adapter box to allow my cables and headphones to run off any amp though, whether it's a SE 1/4" TRS or dual 3-pin XLRs. Flip side is also being addressed, any other cable termination can be adapted to my amps. Actually considering using my balanced TPA Darwin for this role.
Hello BoilermakerFan,
Do you build them or drink them, or both?
Everyone,
I am sitting here with both he and she parts of TRS’s in my hand. The she part has a plastic body. I do not see where a short will happen. Perhaps a metal body grounded to the chassis could cause a short. I prefer the plastic body that does not ground to the chassis. How / where does the short happen?
The current application is a Single End Triode. The output transformer is balanced (Thank You Jack at Electra-Print). The secondary winding is center taped and grounded making the output balanced. Do not pull the plug on this one when it is operating either.
DT
All just for fun!
Do you build them or drink them, or both?
Everyone,
I am sitting here with both he and she parts of TRS’s in my hand. The she part has a plastic body. I do not see where a short will happen. Perhaps a metal body grounded to the chassis could cause a short. I prefer the plastic body that does not ground to the chassis. How / where does the short happen?
The current application is a Single End Triode. The output transformer is balanced (Thank You Jack at Electra-Print). The secondary winding is center taped and grounded making the output balanced. Do not pull the plug on this one when it is operating either.
DT
All just for fun!
I think what can happen is, while removing the plug, the ring contact on the jack can contact the tip contact of the plug while the tip contact on the jack is still contacting the tip contact of the plug. The result being that the two channels' outputs get shorted to each other.
se
That is correct SE. The short only occurs when unplugging the headphones when the amp is powered up. There is a small short when plugging in too, but unplugging is worse and that is usually when the problems occur. Amps like the Beta22 and a modded F5 would be prone to damage during this unplugging without resistors on the jack, IIRC over 100R too, but with a powerful amp like the B22 and F5, the loss at the jack is really minimal, but the amp stays protected.
I'm building in Caddock or Rikens on my TRS jacks for my adapter box, to protect my amp, but also to knock down the power a bit to protect the cans since it will be putting out about 7W at 60R or over 15W at 6R.
Mmm. Don't see why plugging or unplugging would make any difference. A short's a short.
Don't see why they'd need to be any higher than the nominal impedance of the lowest impedance headphones the amp can handle without going up in smoke.
If the amp can drive say, 32 ohm 'phones, then it shouldn't require any more than 32 ohm resistors.
If you're also wanting to attenuate the output instead of just protecting it, then what you might want to consider is a voltage divider instead of a single resistor. That'd let you to keep the output impedance lower than it would be with a single series resistor.
Use something along the lines of 30 ohms for the series resistor, then select the shunt resistor to give you the highest listening level you'll need plus a little extra. It will be only a fraction of the 30 ohm resistor.
Good luck!
se
Yes, I should have edited my first post SE. The short occurs both ways, but it seems to always blow the B22 when the cans are unplugged. But if the amp was off when they were plugged in, then that would always be true. Most owners of the B22s know they have to shut down to change headphones. The damage tends to occur at meets or when alcohol is involved.
I think the higher values were recommended to protect the amps on the small surge with the short. There is certainly enough power there to drive right through a 100-200R network. My 35W/ch vintage Yamaha CR-620 has a 121R resistor network for each headphone jack.
Thanks for the value suggestions on the resistor network. There is a web page that has the formula for calculating the values based on the wattage output of the amp and the impedance of the headphones, but I don't have it handy.
Just stumbled across this thread. (oops!)
I've run balanced for years with a single connector. 4 pin DIN! The locking, screw type with metal body. Works great for me. And I have a short DIN to 1/4" cable that I use when I need to go back to unbalanced. Not tiny, but smaller and lighter than XLR, for sure.
Got the metal DIN at Mouser or Digikey, I think.
I've run balanced for years with a single connector. 4 pin DIN! The locking, screw type with metal body. Works great for me. And I have a short DIN to 1/4" cable that I use when I need to go back to unbalanced. Not tiny, but smaller and lighter than XLR, for sure.
Got the metal DIN at Mouser or Digikey, I think.
Has anyone attempted using 3-wire shielded microphone cable? My ratoinale is that cross talk from the twisted pair to the third wire should be minimal because the equal and opposite currents should create canceling fields. Any 'crosstalk' from currents in the single wire would cancel in the can connected to the twisted pair.
There are 3 wire microphone cables, for example from Gotham, that are ultra flexible though not necessarily small diameter.
There are 3 wire microphone cables, for example from Gotham, that are ultra flexible though not necessarily small diameter.
As the following thread shows, I am not the first to consider this.
Tying in shield for headphone cables (esp. balanced situations)?
The history of bal<->unbal is littered with hums, screeches, and worse between components, but allow me to point out that cans are not a component in the traditional sense. They are more like an MC cartridge, i.e. inherently balanced, while being capable of rejecting common noise.
Please help me discard this idea before I go off and build one if I am "thinking inside the cable" and missing something important.
Tying in shield for headphone cables (esp. balanced situations)?
The history of bal<->unbal is littered with hums, screeches, and worse between components, but allow me to point out that cans are not a component in the traditional sense. They are more like an MC cartridge, i.e. inherently balanced, while being capable of rejecting common noise.
Please help me discard this idea before I go off and build one if I am "thinking inside the cable" and missing something important.
Any kind of zobel network would be for ensuring amplifier stability, as it keeps load impedance low up to the MHz range. This should only be of concern to amplifier designers (in an ideal world where they can be relied on to know what they're doing).
Indeed, headphones are much like a phono cartridge, inherently balanced and floating.
One of the more important points in wiring them up unbalanced is keeping the returns separate for as long as possible, as return resistance common to both channels degrades channel separation. Stock cables for the usual suspects (HD5x8, HD6x0, various AKGs etc.) implement that already.
Even a common ground connector does not necessarily spell disaster though, as long as its resistance is less than about 1% of minimum driver impedance. (Example: HD590, ~1 ohms vs. 100 ohms.) 40 dB of channel separation should be plenty on cans if even 12 dB of imbalance already is painful and vinyl gets along fine with <30 dB.
Ideally, the cable for a balanced headphone connection should have either 2 conductors and a shield per channel, or 4 conductors plus shield for both. Shield would be connected at the amp only.
Anyway, people tend to put a lot of emphasis on electrical characteristics. IMO, they're not even all that important (assuming capacitance doesn't skyrocket or resistance exceeds ~10% of minimum impedance). You do want the cable to be light and mostly devoid of microphonics though, and it would be nice if it didn't break after a week of use. Sennheiser had massive cable reliability problems with the thin copper cables they originally supplied with HD414s way back when, so they eventually switched to somewhat microphonic but tough steel-conductor cables (still to be had with HD25-1s these days). It would take them about 15 years to come up with the kevlar fiber reinforced copper cables they usually supply nowadays (low microphonics and decent durability).
Indeed, headphones are much like a phono cartridge, inherently balanced and floating.
One of the more important points in wiring them up unbalanced is keeping the returns separate for as long as possible, as return resistance common to both channels degrades channel separation. Stock cables for the usual suspects (HD5x8, HD6x0, various AKGs etc.) implement that already.
Even a common ground connector does not necessarily spell disaster though, as long as its resistance is less than about 1% of minimum driver impedance. (Example: HD590, ~1 ohms vs. 100 ohms.) 40 dB of channel separation should be plenty on cans if even 12 dB of imbalance already is painful and vinyl gets along fine with <30 dB.
Ideally, the cable for a balanced headphone connection should have either 2 conductors and a shield per channel, or 4 conductors plus shield for both. Shield would be connected at the amp only.
Anyway, people tend to put a lot of emphasis on electrical characteristics. IMO, they're not even all that important (assuming capacitance doesn't skyrocket or resistance exceeds ~10% of minimum impedance). You do want the cable to be light and mostly devoid of microphonics though, and it would be nice if it didn't break after a week of use. Sennheiser had massive cable reliability problems with the thin copper cables they originally supplied with HD414s way back when, so they eventually switched to somewhat microphonic but tough steel-conductor cables (still to be had with HD25-1s these days). It would take them about 15 years to come up with the kevlar fiber reinforced copper cables they usually supply nowadays (low microphonics and decent durability).
Thanks for the rules of thumb for cable resistance. My first attempt was with Mogami 3106 stereo microphone cable. Twin pairs of twisted conductors, separately shielded so it fully meets your ideal. It leaves something to be desired in terms of useability. I recently held a length of Gotham GAC-3 and thought how wonderful it would be to have that flex in a headphone cable. That started my 'inside the cable' thoughts.
Now I am questioning what parts of the ideal might be relaxed at little (or better, no) loss in quality. Is shielding really needed? Might it instead be used as the fourth conductor? It was at that point that I posted my thoughts above and then found RaneNotes on shielding, grounding, and audio interconnect. My thoughts fall under "Floating, Pseudo, and Quasi-Balancing" but I am undeterred :-(
Gotham has graciously provided three and four conductor cabling at what seem to me quite low prices. Surprisingly they sell cut lengths to one and all. I will add connectors and test for crosstalk differences between GAC-3 and GAC-4 (four conductors in a single shield). I will also test against Mogami dual, separately shielded, twisted pair.
Now I am questioning what parts of the ideal might be relaxed at little (or better, no) loss in quality. Is shielding really needed? Might it instead be used as the fourth conductor? It was at that point that I posted my thoughts above and then found RaneNotes on shielding, grounding, and audio interconnect. My thoughts fall under "Floating, Pseudo, and Quasi-Balancing" but I am undeterred :-(
Gotham has graciously provided three and four conductor cabling at what seem to me quite low prices. Surprisingly they sell cut lengths to one and all. I will add connectors and test for crosstalk differences between GAC-3 and GAC-4 (four conductors in a single shield). I will also test against Mogami dual, separately shielded, twisted pair.
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