Ground loops

[Petrushka]

NO,.. Why??
The OP, has yet to even 'Run' his System up,..
There is so far NO problem of Any kind whatsoever,.. this is all theoretical disasters,.. LOL

On a different forum, someone complained about hum, then said it went away when using a different outlet.

 

[stoo23]

Yes but so far everything here is dealing with an issue the OP has yet to even have or experience,.. interesting really

 

[Sokel]

On a different forum, someone complained about hum, then said it went away when using a different outlet.

If we want to max this up and the country allows it,same outlet - different plug orientation too.

(the fun part is that OP probably will need nothing of the above)

 

[antcollinet]

Sorry, you are completely Wrong my friend,.. or you have never been drawing serious current through any 240v cables !!
I have seen a fire start because of this and once managed to disconnect a very lengthy mains cable that had been coiled behind and under the Stage curtain, where the insulation had become So soft, it was starting to melt together,.. a few more minutes and trouble would have ensued !!!

Seriously I speak of what I know !!!
MANY years in the Live music arena,..
BTW, If as you suggest the 2 x conductors cancel each other's field, what are you actually suggesting ?? What 'field' and how does that field have anything to do with heat generated by current flow ?? ... Answer

I did say btw: "One should never Flat Coil Power cables, especially if drawing decent current, as heat can build up and cause problems !!" it was simply a precautionary warning regarding High current draw and Heat. ... Simple really.

Try it with 3-Phase lighting cables and see how long it takes to get dangerously HOT

I think you need to read @Speedskater s post again - he wasn't saying you can't get heat - he was saying you don't need figure 8 to avoid magnetic fields.

 

[stoo23]

No, I don't, .... as I never mentioned Magnetic fields,in the first instance.
As I pointed out again, in a following post, I was simply suggesting the danger of coiled Mains cables generating enough heat to be a problem.

Plus, there are two schools of thought on the theoretical cancellation of magnetic fields in coiled cables !!
Perhaps if coiled in the 'Over-Under' method it's possible, otherwise not.

Try googling it

 

[Holmz]

No, I don't, .... as I never mentioned Magnetic fields,in the first instance.
…

Try googling it

No thanks.

It started out with “Ground Loops” as the topic title.
We have gone full circle (d3/dt3) on fires and heat, but lost the thread on the hum.

 

[antcollinet]

No, I don't, .... as I never mentioned Magnetic fields,in the first instance.

Your statement was "no you are completely wrong"

There was nothing wrong in the post you were replying to.

 

[AnalogSteph]

I think I know what to do. I won't have the DAC for a while since I'm waiting for it to go on sale. But, I can get the amp, and get a cheap RCA to 3.5mm splitter since I want to experiment with preamp out to my mini soundbar anyways, and use it to connect the amp to the headphone jack of my current USB dongle. Then see if I get noise. Unless I'm missing something, I think that should be a good simulation. Then I'll know ahead of time whether I need a ground loop isolator, or can just use regular interconnects, so I won't have to double-dip, and won't have any money in that I wouldn't otherwise. That setup will be a Topping D10S into a Schiit Magni Heretic if you're curious btw (though you might already know that from my other thread, Doug).

None of the equipment mentioned should give you any substantial trouble with ground loops, it should all be equipped with floating power supplies.

If you were to try to use typical home studio monitors instead, it would be quite a different story.

 

[stoo23]

Look, let's just give up on this eh ??
You guys are literally 'fixated' on this Hum issue,.. my original post, simply included some advice regarding NOT coiling Mains cables, so as to avoid dangerous Heat build up,.. if you read it again, I did NOT mention ANY kind of Field in relation to that. That said, there is (as suggested) two schools of thought on whether or not the 'Fields' are cancelled, as there does seem to be evidence that perhaps they aren't 'Nulled' and can actually contribute to the heat issue. I have no specific refential evidence of this myself.

I accept that suggesting the person was wrong by quoting the whole statement was poor editing on my behalf,... what I was specifically intending to refer (once again to the concept of reducing heat) with reference:

There is no need for a 'Figure-8' pattern

You ALL may not think so but in high current situations, it is a great way to allow plenty of air around the cables to avoid heat build up.
I'm 67, have worked and toured extensively, for nearly 40 years with many local and international artists, so I'm not simply shooting my mouth off, I was merely suggesting what is arguably best practice in the Professional Concert touring industry, ... but go right ahead, do what you like, I don't care,... perhaps ask an electrician.

Also, if you coil mains cables you can reduce their current carrying capacity severely !!
One of those typical Camping style units can only carry about 3 to 5 amps when coiled, yet 8 to 10 when fully laid out.

I'll leave you once again, with the hum that as yet, doesn't exist,.. .... interesting that I have been clobbered for trying to offer some Safety information ,... a very popular and famous Talking Heads song seems to come to mind,...all of a sudden,.. LOL

 

[antcollinet]

interesting that I have been clobbered for trying to offer some Safety information being rude.

fixed that for you

 

[stoo23]

Wow,.. you have obviously decided you Don't like me !!
I respectfully suggest my posts and replies have been both metered and civil and I have neither intended to be or wanted to be Rude.
I have 'no beef' with anyone here, especially not yourself and am seriously having difficulty understanding why you are (in effect), 'On my case' here but no matter.

I'll do my best to avoid further interaction with yourself.

 

[Doodski]

Wow,.. you have obviously decided you Don't like me !!
I respectfully suggest my posts and replies have been both metered and civil and I have neither intended to be or wanted to be Rude.
I have 'no beef' with anyone here, especially not yourself and am seriously having difficulty understanding why you are (in effect), 'On my case' here but no matter.

I'll do my best to avoid further interaction with yourself.

Hi @stoo23. I have experienced issue with coiled power cords combined with satellite TV dish cable and speaker wire. The issue was that a tiny tiny signal from the 12 foot mesh satellite dish LNB amp was distorted and the picture went sparkly and distorted. It was a sizeable coil about 18" in diameter and about 3" thick. I went to the customers house and uncoiled his very neatly done tight coil and all was well after.

I have seen a degausing coil for old CRT television get hot. That is a coil about 1 to 2 feet in diameter and tightly coiled small gauge copper conductor.

Otherwise I have not seen any serious issue with home audio gear.

 

[stoo23]

Otherwise I have not seen any serious issue with home audio gear.

No,.. Probably not ...
It all depends on the Cross sectional area of the cable in question and the current being drawn

 

[Doodski]

No,.. Probably not ...
It all depends on the Cross sectional area of the cable in question and the current being drawn

Yes, I agree as well as the density of the windings and on and on it goes.

 

[GreeneDeux]

Got everything hooked up for a quick test, no hum as far as I can tell... there is a moderate hiss on medium-gain and a loud hiss on high-gain, but the StarTech dongle has a slight hiss anyways so I figure that's just being amplified. Actually, the wall wart doesn't have a ground pin at all, so is a ground loop even possible?

It's too bad Schiit doesn't also sell through Amazon or something, the shipping costs buying from them are so prohibitive that this is probably the only thing I'll ever get from them - my all-in total was $159 CAD, so between taxes and shipping it was $77 just to get it from there to here. Would absolutely not have made sense to buy if it wasn't on such a massive discount.

One other thing I don't hear is an improvement in sound quality, but since I've got it hooked up to the StarTech headphone-out I suppose it can't make it sound any better than the weakest link... hopefully that's correct or else this may have been a waste.

 

[Doodski]

Got everything hooked up for a quick test, no hum as far as I can tell... there is a moderate hiss on medium-gain and a loud hiss on high-gain, but the StarTech has a slight hiss anyways so I figure that's just being amplified. So, now I just need a DAC.

It's too bad Schiit doesn't also sell through Amazon or something, the shipping costs buying from them are so prohibitive that this is probably the only thing I'll ever get from them - my all-in total was $159 CAD, so between taxes and shipping it was $77 just to get it from there to here. Would absolutely not have made sense to buy if it wasn't on such a massive discount.

One other thing I don't hear is an improvement in sound quality, but since I've got it hooked up to the StarTech headphone-out I suppose it can't make it sound any better than the weakest link... hopefully that's correct or else this may have been a waste.

I got dinged heavy on the duty and extra charges too for shipping to Canada. But I paid up and am enjoying my Schiit headphone amp. Gobs of power and sounds good loud. I would appreciate a new set of Sennheiser 600 or 700 series phones. The DACs will not sound that much different from each other...

 

[GreeneDeux]

The DACs will not sound that much different from each other...

The StarTech dongle I use has no DAC-out so it's going through two amps in my test configuration.

PC -> USB StarTech dongle -> 3.5mm headphone jack -> 3.5mm-to-RCA combiner -> Schiit RCA-in

 

[Holmz]

Got everything hooked up for a quick test, no hum as far as I can tell... there is a moderate hiss on medium-gain and a loud hiss on high-gain, but the StarTech dongle has a slight hiss anyways so I figure that's just being amplified. Actually, the wall wart doesn't have a ground pin at all, so is a ground loop even possible?

It's too bad Schiit doesn't also sell through Amazon or something, the shipping costs buying from them are so prohibitive that this is probably the only thing I'll ever get from them - my all-in total was $159 CAD, so between taxes and shipping it was $77 just to get it from there to here. Would absolutely not have made sense to buy if it wasn't on such a massive discount.

One other thing I don't hear is an improvement in sound quality, but since I've got it hooked up to the StarTech headphone-out I suppose it can't make it sound any better than the weakest link... hopefully that's correct or else this may have been a waste.

Hiss is not a ground loop.

 

[antcollinet]

Hiss is not a ground loop.

It technically could be if the ground noise source were wide band.

But I've only ever heard it as either mains frequency hum, or "pc noise"

 

[Doodski]

It technically could be if the ground noise source were wide band.

But I've only ever heard it as either mains frequency hum, or "pc noise"

Same here. I've heard crackling and hissy stuff from overheated BJTs but not from any ground issue.