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How does an RCA input improve anything over a balanced input fed from an RCA output with adapter cable?
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XLR - RCA maximum length?
- Thread starter _Bass
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Keeping single end like RCA is alway safe from his current system even he want run to 9 meter long. Using adaptor(no balance in electrical signal even it is RCA-XLR), your chance of getting hum, hiss, noise along the way as there are threads about it already. My suggestion is to save problem.
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But it does nothing of the sort. RCA to RCA is as likely to get a hum problem from ground loops as RCA to XLR. You have saved nothing.
Threads here about RCA-XLR problem are more. Plus there is no noise rejecting using RCA to XLR at all. You still have hum and ground loops.
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Makes no difference. Balanced to Balanced is to have differential signals that won't hum. If you go single ended, ground loops are more likely. When going RCA to RCA same problem as going XLR-RCA. You are only using half the XLR and that makes it single ended with the ground connected devices often having different safety ground. You hear more complaints about it because most active speakers have balanced input and are more likely to be placed at a distance to AV receivers having only RCA outputs. Having RCA at both ends does nothing to alter the problem. With either version of single ended you aren't floating the signal, but using ground for one of the connections of the signal being transferred.
One option would be to use long extension power cords from the surround speakers going into a multi electrical outlet back at the receiver end. That way the devices share the same ground and hum is unlikely.
Ground one pin of XLR, you are creating another loop problem. One signal, two grounds. You have voltage potential difference since one is cable core, one is shielding reference to a ground. Compare to RCA, one signal, one ground. If there is no grounding issue, you created anther one with RCA-XLR adaptor because of shorted pin and shielding.
Waxx
Major Contributor
12m is on it's own not an issue, but hum and ground loops could happen. If you want to use balanced, you will need balanced out also. There are devices like the Radial JPC that do that conversion for you and do work right. I used this a lot when i was doing engineering for high power dj setups. You connect the device of the dj (often a own dj mixer, laptop or a sampler) to that device with short rca cables, and from that device to the (pa) mixer with xlr balanced, and so you avoid hum and ground loops.
But try first with rca cables (and a conversion part if needed), the chance is very big that there are no issues that way in a home setup. I did it for years over 20m without issues.
But try first with rca cables (and a conversion part if needed), the chance is very big that there are no issues that way in a home setup. I did it for years over 20m without issues.
Yes, because ground lift only lifts the audio ground, safety ground.stays connected always.
- Thread Starter
- #29
Let me clarify a couple of things. I already purchased Genelec 8030s and they are on their way. The only input they have is XLR and I will be hooking them up to my AVR as surrounds (mains are the same and work fantastic). As per the Genelec manual, the RCA signal should be wired to pin 2 of the XLR which is what I see in Monoprice's cables.
I will have my 2nd subwooder close to one of the surrounds (and for that I also am considering a 12 meter RCA-RCA cable), and since the surrounds and sub are active, naturally, they will be close to outlets. Voltage is standard 220V for Europe.
I will have my 2nd subwooder close to one of the surrounds (and for that I also am considering a 12 meter RCA-RCA cable), and since the surrounds and sub are active, naturally, they will be close to outlets. Voltage is standard 220V for Europe.
You can try as suggestion for XLR-RCA and make sure it is wired in that way. If any noise induced, you may end up buy active RCA-XLR preamp or DI boxes. Make sure it is opsamp type not transformer type. For subwoofer RCA, you can consider using RG59 type coaxial cable.
Speedskater
Major Contributor
a Ground Fault Circuit Interrupter does NOT perform the primary function of the Safety Ground system.
the Safety Ground system's primary function is to trip the circuit breaker if there is a 'ground fault' (short circuit).
Speedskater
Major Contributor
Just what are you writing about?
1] an AC power Safety Ground lift?
2] a XLR balanced interconnect shield lift? (XLR does not have a ground)
2] something else?
1) Absolutely NOT!!! The mains safety earth stays connected always.
2) The connection between chassis (i.e. safety earth) and audio earth can either be joined or separated with a resistor (or resistor capacitor pair) under control of a switch.
XLR Pin1 should go directly to chassis and nowhere else, but very rarely does as a lot of equipment wrongly takes Pin 1 to audio earth. The well known Pin 1 problem.
S.
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If the chassis ends up somehow at 120 volts, and you touch it you could be electrocuted. If the chassis is connected to 3rd pin or Safety ground it would ground the chassis and blow the breaker protecting you.
If there is no Safety ground and the chassis reaches 120 volts, and you have a GFCI outlet? When you touch the chassis the GFCI outlet will disconnect power when the difference in current going into the outlet is different from current going out by 4-6 milliamps (something like 50 mA or higher could be fatal). In a matter of microseconds it would act. So if you touched the electrified chassis, and current was starting to flow thru you, it would fire and protect you. Same protection via a different means.
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Some gear allows you to disconnect pin 1. This way the chassis ground in one piece of gear is not connected to the other and ground currents cannot flow. Which prevents ground loops. Both pieces of gear would still have Safety ground on both ends. Perfectly safe.
You cannot do that if you are going to connect RCA and XLR because pin 1 is going to be connected to one of the other pins (usually pin 3 I think). For balanced connections it is fine.
Speedskater
Major Contributor
Yep, the GFCI will protect human life if there is a 'ground fault' (short circuit).
But if there is a 'ground fault' and your system stops working and then you remove the RCA at the wrong end and then plug it into another unit, the hot RCA connector will blow the other unit long before the GFCI trips.
Speedskater
Major Contributor
The infamous XLR "Pin 1 problem' doesn't just apply to XLR interconnects. It applies to all cable shields. Any and all cable shields should be attached to the chassis at their connector.
Some XLR cables may have their shield attached only at the send end. But they should add a hybrid capacitor at the receive end. Or high frequency interference rejection will suffer.
Some XLR cables may have their shield attached only at the send end. But they should add a hybrid capacitor at the receive end. Or high frequency interference rejection will suffer.
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Still no harm to the person, and whether it blows the other unit is a maybe. It might just flow to ground over the other chassis. If we are down to the plug protecting all attached gear from all other faults we have a ways to go.
sam_adams
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Some examples of 'ground lift' switches in balanced audio situations (Bill Whitlock - Audio Transformers - Jensen AN-008 and Handbook for Sound Engineers, Third Edition, Glen Ballou, Chapter 11, Audio Transformers):
GFCI outlets can be wired without a ground as long as the outlet indicates that there is no safety ground connected to the outlet as per NEC code in US. The GFCI circuitry senses the difference between the line and neutral current flow and will trip the circuit open when there is a 5 mA difference between them.
Using a 'cheater' plug to lift the safety ground specifically to reduce noise is a violation of NEC code.
Also, it's just as bad to use one of Paul's special AC power cords with the removable ground pin:
The situation below is still better than a simple unbalanced cable (from Bill Whitlock - Interconnection of Balanced and Unbalanced Equipment - Jensen AN-003):
GFCI outlets can be wired without a ground as long as the outlet indicates that there is no safety ground connected to the outlet as per NEC code in US. The GFCI circuitry senses the difference between the line and neutral current flow and will trip the circuit open when there is a 5 mA difference between them.
Using a 'cheater' plug to lift the safety ground specifically to reduce noise is a violation of NEC code.
Also, it's just as bad to use one of Paul's special AC power cords with the removable ground pin:
The situation below is still better than a simple unbalanced cable (from Bill Whitlock - Interconnection of Balanced and Unbalanced Equipment - Jensen AN-003):
