Making custom cables 1/4" TRS and RCA ( combos )

[DANGERDAN]

Im wanting to create some custom cables for my stereo system as i believe it will save money and get possibly higher quality connection in the long run, i have a few questions about this sort of set up and hope someone can help.

With TRS i understand there are three connectors left right and common ground, i want to know what the purpose is of the common ground its job and is it needed.

Second is about the shielding and if it is recommended to have with jumpers and or power cable, also i was told that you do not have to ground shielding but from what i know you must as it insures a much better connection and reduces interfierence dramatically.

Much help would be gratefull.

[cbope]

The common ground of a TRS plug/socket is needed as the return path for both the L and R signals, the cable won't work without it. However, if you are making a cable with TRS on one end and RCA on the other, there is no point to use TRS on one end because an RCA on the other has only 2 conductors, the ring or outer part and the pin in the center while TRS is 3. You probably want to use TS, which has 2 conductors. But, I am making an assumption here because you did not mention the use of these cables.

Regarding shield grounding, the best method I am aware of is to ground only one end and leave the other end unconnected. This is to prevent creating a ground loop between the 2 components which can introduce noise and/or hum. The shield will still do its job even with only one end connected, which is to shunt external noise to ground.

[DANGERDAN]

Ah yea that makes sense, when you say the ground is for the return im confused how both left and right channel use the same return and not interfeir with each other ?. wouldnt each channel need its only return for the AC to match correctly to the polarity of the signal ??.

If i was wanting to make RCA for both left and right channel i would need to use TRS wouldnt i to make use of stereo as a TS would only be mono.

Ok so for shielding if it was not grounded would it be rendered useless compared to it having no shield as the noise would not be redirecting the noise to the ground, if anything it would be worse ??? as noise would be introduced into the cable ??.

[cbope]

The shielding may still work somewhat if it's not connected at either end, but it won't work that well. It really depends on the amount of noise preset.

If you want to run stereo signals you would need TRS and either TRS or 2x RCA's at the other end. If mono, then TS and RCA at the other end.

Don't worry about the common return. Take a look at your headphone plug, it's either TRS or mini-TRS (3.5mm or 1/8") and it has a common return for both drivers.

[DANGERDAN]

Thanks for your help it does make sense i just would like to understand the return, as with all things i take interest in i like to fully understand everything to better understand the technology and improve my knowledge of it all..

So you say both drivers (channels/speakers) have a return path (common ground) but hows that possible when its using the sleeve connection ??, if im not mistaken tip/ring for left and right or vice versa and sleeve for common ground.

If its not too much trouble i would much appreciate .

[Marvel]

So you say both drivers (channels/speakers) have a return path (common ground) but hows that possible when its using the sleeve connection ??, if im not mistaken tip/ring for left and right or vice versa and sleeve for common ground.

Most equipment uses a common ground, hence the sleeve/shield works just fine. You can verify/confirm this with a multimeter by setting to ohms or continuity and the rca shield on a right/left pair.

Bruce

[cbope]

The sleeve is the ground or return. You can learn more than you ever wanted to know here: http://en.wikipedia.org/wiki/TRS_connector

Note, the type of TRS we are referring to here is the unbalanced stereo type. Scroll down to the section titled "tip/ring/sleeve terminology" for the meat.

[DANGERDAN]

Ok so in order to run stereo audio with 1/4" plugs i have to connect the
left and right channel to each other and the ground in a ground-loop
connection in order for it to work no ?, after some research on this
matter and also looking into unbalanced vs balanced theory i have come
to some ideas about the technology.

Because TRS uses the same ground connection for the return path could
this not pose problems with crosstalk and also decrease quality of sound
compared to a fully unbalanced connection or a balanced connection as
they would have their own return path ??.



Also as for grounding i would have to say its vital to ground a sheild
to ensure maximum potential of the rf shielding otherwise it will not
work to its full extent.

also TRS are considered unbalanced when they are run in stereo and when in mono they are balanced ??

[cbope]

(edit: formatting fixed)

I can't realy comment if the common return will cause problems or not, as I have never tried this kind of connection with audio components. Hopefully someone else can help.

Regarding balanced vs. unbalanced, practically all consumer level audio uses unbalanced signals. A balanced signal requires 3 wires, a ground or return, the signal and an inverted signal that is exactly opposite of the signal. In a balanced configuration the inverted signal is used to cancel out any noise picked up in the cable over longer runs. The equipment must be able to generate this inverted signal on the out jack and of course it has to subtract it at the in jack at the other end. Balanced connections are mainly used in professional music gear, where long cable runs can be used. If the equipment does not have balanced ins and outs, you will not get any benefit using an balanced cable because there will be no inverted signal. Common consumer audio is always unbalanced although there are some exceptions.

While balanced connections can be made using TRS connectors, it is less than ideal because the signal is momentarily shorted when the plug is inserted and this typically causes pops in the audio which can damage speakers. Professional-level balanced connections use a different kind of connector called XLR, which always connects ground first and does not short the signal pins when connected. The XLR connector has 3 pins.

In short, it's the components used that determine balanced or unbalanced, not the cable itself. You can use an unbalanced cable between two balanced components, but the inverted connections will be grounded at each end and you will lose the benefit of a balanced connection. Using a balanced cable between two unbalanced components will not magically give you a balanced connection, it will still be unbalanced although it will work fine.

[DANGERDAN]

Yea after a little more research i think the audible quality between the two are the same, the difference between them is just with noise control over distance. I think also that balanced cables can handle more power and control and that unbalanced is more for headphone or line level audio transfer.

Why i ask all this is because the current cables im using to connect my
headphones to the amp are less in sound quality than it is when
connected directly without extension cable, the cable is about 4m long
and not of high quality. Would this drop in quality be attenuation and
lack of quality cable material causing a significant drop in clarity in
the highs and lows ??.

[cbope]

Yes, it's very likely that a low-quality extension cable is causing some degradation. I never use extensions on headphones, the plug always goes straight to the headphone jack on the amp. A 4m cable extension in addition to the built-in cable (usually 2-3m) is quite long if you want to preserve full quality. A headphone amp plus a good quality cable may help. I would start wih a better quality extension cable, since it is the least expensive option and see if the improvement is enough. If not, a good quality headphone amp may improve it, but that is not an inexpensive option. A good headphone amp runs a couple hundred dollars for an entry-level unit and prices can easily exceed $1000.

[DANGERDAN]

Im already using a high quality headphone amp so i will work on making some custom extension cables i think, 14 gauge would do i think just a tight fit haha xD.

[MikeFord]

Yea after a little more research i think the audible quality between the two are the same, the difference between them is just with noise control over distance. I think also that balanced cables can handle more power and control and that unbalanced is more for headphone or line level audio transfer.

Why i ask all this is because the current cables im using to connect my
headphones to the amp are less in sound quality than it is when
connected directly without extension cable, the cable is about 4m long
and not of high quality. Would this drop in quality be attenuation and
lack of quality cable material causing a significant drop in clarity in
the highs and lows ??.

Wire or even connectors I doubt are your problem, your hooking headphones up to circuits that are not made to drive headphones.

RCA connections are not designed to drive headphones. RCA connections are typically low level signals, and expect a high impedance load (10k ohms), which headphones are not. The resulting sound will vary depending details of the circuit, what sort of protection it uses for low impedance loads, but less than ideal is very likely.

Using a headphone amp with RCA inputs and TRS headphone outputs should solve your problem. Other solutions are possible, but might not be so simple, and could depend on the specific devices, headphones etc. that you are using.

[MikeFord]

What sort of headphone amp would have RCA outputs?

Headphones use tiny gauge wires internally an in there cables as they require almost no power to operate, use of 14 gauge would work, but 28 gauge or even 32 might work equally well, and none should alter the sound materially in quality, just some power loss.

Please explain, just list out your whole signal chain with specific devices and connections.

[DANGERDAN]

Computer sound card as pre amp (asus xonar d2x), connected with extension cable about 4 meteres long to another cable (3.5mm to L/R RCA) which connects to the main power amplifier (main in). Then a extension cable hooks up to the HP output of the amplifier (4m again) back to my headphones.

These cables are run along side multiple different cables but i do not detect any noticeable noise on the line, im certain that noise cannot affect quality of sound but only add disruptive background noise that may hinder the sound as a anoyance.

Headphones are about 100ohms i am probably looking into using 12 guage cable if i can as i have a tuck load to use if not will look into something smaller 15-20 maybe.

[MikeFord]

Computer sound card as pre amp (asus xonar d2x), connected with extension cable about 4 meteres long to another cable (3.5mm to L/R RCA) which connects to the main power amplifier (main in). Then a extension cable hooks up to the HP output of the amplifier (4m again) back to my headphones.

Should work fine with any normal inexpensive cables. How do the headphones sound plugged directly into the HP output of the amp?

The amplifier is a headphone amp? Which one?

[DANGERDAN]

Its the marantz amp in my profile list, not made for Headphones but it does give a better current than the sound card does and is a noticeable improvement in sound quality, when the headphones are connected directly into the HP jack of the amplifier it sounds a lot cleaner. The quality difference is distinct separation in music instruments, tighter bass and clearer highs.

Edit: I dont think the average person would be able to notice this however, i seem to have some sort of understanding on telling the difference between quality of sounds.

[MikeFord]

Its the marantz amp in my profile list, not made for Headphones but it does give a better current than the sound card does and is a noticeable improvement in sound quality, when the headphones are connected directly into the HP jack of the amplifier it sounds a lot cleaner. The quality difference is distinct separation in music instruments, tighter bass and clearer highs.

Edit: I dont think the average person would be able to notice this however, i seem to have some sort of understanding on telling the difference between quality of sounds.

Wow, maybe you are an audiophile. I have heard of them, many have golden ears with ability to hear things beyond the kin of the average bloke. Something about extra placebo in their blood or could be lack of vitamin ABX, which often clears up the condition.

I think I understand your system, and this is what I would suggest.

Use the supplied TRS to RCA cables for now.

Make sure the sound card has the latest drivers, and is setup properly for how you have it connected. It supports many modes that will alter the sound, and some of them may be defaults that must be manually deselected. It may also automatically change modes depending on what it thinks is connected to it.

Buy a good quality headphone extension cable.

Consider going to a dedicated headphone amp.

Good luck.

[DANGERDAN]

Wow, maybe you are an audiophile. I have heard of them, many have golden ears with ability to hear things beyond the kin of the average bloke. Something about extra placebo in their blood or could be lack of vitamin ABX, which often clears up the condition.

I think I understand your system, and this is what I would suggest.

Use the supplied TRS to RCA cables for now.

Make sure the sound card has the latest drivers, and is setup properly for how you have it connected. It supports many modes that will alter the sound, and some of them may be defaults that must be manually deselected. It may also automatically change modes depending on what it thinks is connected to it.

Buy a good quality headphone extension cable.

Consider going to a dedicated headphone amp.

Good luck.

Haha i laughed a bit at the sarcasm, what i ment was a lot of people cant tell the difference between things like mp3 bitrate low/high where as i can tell drastically and cant stand anything but 320 and even then i still prefer cd quality when you have the right equipment paired with the material.

Anyway i have some extended knowledge about audio and know everything there is about the sound card, if anything i would be looking into a dedicated external DAC as a pc soundcard cannot quite cut it in regards to pre amp technology. Iv been looking into DAC magic (cambridge) but probably will leave that last after a new proper amp and probably some better cabling as i do believe the cables are dropping performance as they can do with attenuation.

[RRFL]

Wow, maybe you are an audiophile. I have heard of them, many have golden ears with ability to hear things beyond the kin of the average bloke. Something about extra placebo in their blood or could be lack of vitamin ABX, which often clears up the condition.

I think I understand your system, and this is what I would suggest.

Use the supplied TRS to RCA cables for now.

Make sure the sound card has the latest drivers, and is setup properly for how you have it connected. It supports many modes that will alter the sound, and some of them may be defaults that must be manually deselected. It may also automatically change modes depending on what it thinks is connected to it.

Buy a good quality headphone extension cable.

Consider going to a dedicated headphone amp.

Good luck.

Haha i laughed a bit at the sarcasm, what i ment was a lot of people cant tell the difference between things like mp3 bitrate low/high where as i can tell drastically and cant stand anything but 320 and even then i still prefer cd quality when you have the right equipment paired with the material.

Anyway i have some extended knowledge about audio and know everything there is about the sound card, if anything i would be looking into a dedicated external DAC as a pc soundcard cannot quite cut it in regards to pre amp technology. Iv been looking into DAC magic (cambridge) but probably will leave that last after a new proper amp and probably some better cabling as i do believe the cables are dropping performance as they can do with attenuation.

Have a look at the ARCAM rDAC it is particularly good for USB connection from a Computer. With the rDAC you can use any old computer to access your NAS and connect via RCA to your pre-amp/receiver.