Shielding Speaker Cables - ** HOW **

[TrevC]

thaks foir the feedback

i've lived in the house for 10 years. about 2 years ago the wiring circuits were routinely inspected and i have a safety certificate.

The question is

CAN I SHIELD SPEAKER CABLES FROM ELECTRICAL INTERFERENCE and

WOULD THAT SHIELDING ACTUALLY DO ANYTHING BENEFICIAL.

You can do it, but there isn't any benefit.

 

[smarkgee]

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thanks guys - it is appreciated

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I am trying once again to power it all froma different circuit in the house.

I will get a sparky in.

follow on question

1. What is the sparky actually checking for? As I said I already have a basic certificate which shows there are no shorts and everything wired correctly on the house's various circuits.

2. The speaker cables and amp are centimetres away from the MAIN HOUSE FUSE BOX (modern) and presumably the mains power going into that - can that create any interference that may be the problem?

remember the power amp or a repalcement connected to no source with any of 2 correctly wired speaker cable sets with a set of correct resistance resistance or a nother pair of speakers can replicate the prob so it CANNOT be the equipemnt. it must either be main related or related to the proximity of the equipment to something

 

[cheeseboy]

just wait for the sparky to come round and show him what happens with the amp and let him take it from there.

 

[smarkgee]

@cheeseboy ty

another thought crossed my mind

i've run an extension cable from a different ruing main...still does it.

it only happens occasionally and is not repeatable...prob when the sparky comes (luckily i know one who lives 4 doors away!!)

one thought tho. i run a Pc and pre and power amp and dac all from the same socket on an extension lead. might that be a prob eg could it be the PC doing something that causes it to need more power that causes the amp to lose power???? i have them all on an extension lead as the extension lead has some sort of circuit breaker and filtering in it before you say i'm mad!!

i'm going to try putting the power amp into a socket of its own

 

[BigH]

Sounds like you are overloading that ext. lead. You may be better to get the sparky to put in a new socket, no switches, just for the hifi.

 

[RobinKidderminster]

Sorry if a slight highjack? Speaker and mains shouldn't run alongside but surely they usually will. Mine do! Is there any point in shielding in this circumstance?

 

[smarkgee]

well yes, i assume lots of people do but thought i'd ask!!

mine is also next to the fuse box where there are lots of circuit and the proper main cable coming in.

and also the only using one socket thing is a possible cause as well...i don't know the electrical formulae behind it all

 

[smarkgee]

well i've now had the elexctrics checked, i've HAD PUT IN a dedicated ring main. still have probs

my cheap sony amp works much better than my arcam pre and power amp but still has very bad degradation.

i can hear the degradation with headphones plugged in the amp - so i guess that takes out the speaker wires.

i wrapped the interconnect with tin foil (shielding) and that seemed to help (from the DAC to the amp - i have 2x DACS neither eliminates the prob). Then i bought some proper shileded interconnects and they seem worse than the tin foil if anything.

eesh...the years pass.

 

[Vladimir]

Have you tried pluging your gear through an AVR (Automatic Voltage Regulator with DC filter) instead of pluging it straight in the mains?

 

[Tannoyed]

Hello

When you say the amp 'trips' what exactly do you mean? Does it revert to standby? Does it trip an MCB circuit breaker on the distribution board or does it trip the Earth Leakage Circuit Breaker (ELCB or RCD)? on the same board.

The first option often happens when compact fluorescent lamps interfere with the remote control receiver in the amp (if that is, it has one). Cover the sensor and see what happens.

To trip an MCB would require a substantial overload. These devices sense excessive current demand and trip out when the rating is exceeded. The MCB may be faulty, especially if the amp is otherwise working normally.

ELCB's can nuisance trip. An ELCB detects an imbalance between the line and neutral currents, in this case feeding the mains transformer in the unit. Any current imbalance above a certain threshold (usually 30mA) will cause the ELCB to trip. The stray current is leaking to earth so if it is this, it seems likely that there is an earth leakage fault within the unit, probably in the mains transformer.

Screening speaker wires is futile unless of course the common mode rejection ratio of the amplifier circuits is hopeless and/or you live next to a 10kW ERP transmitter!

Filters in equipment and particularly in extension leads designed to protect computers against supply spikes, can cause tripping of ELCB's because the means of filtration is of necessity, a leakage path in itself.

 

[smarkgee]

@tannoyed ty 4 your input

when the power amp trips the on light goes from green to amber. the master circuitry on the fuse box does not trip

remote control: there is none on the cheap sony amp

ELCB - i have a new dedicated ring main. housed in a different (newer) fuse box

there is sound degradation and / or channel loss with the cheap amp. samp with the arcam but it trips more readily (presumably better internal protection)

extension lead filter. hmm. i could try that. i could put the amp back onto the old mains circuitry

 

[smarkgee]

Have you tried pluging your gear through an AVR (Automatic Voltage Regulator with DC filter) instead of pluging it straight in the mains?

hi Vlad, thank you for your input.

no i have not tried that (I think). what exactly are they ? (I've googled it and a lot comes up)

I do use an extension lead with surge protection and filtration in it.

 

[smarkgee]

Maybe you need to get a sparky around to check out the house electrics.

As I said before you need to get a sparky in, your wiring does not sound safe and could cause a fire.

+1

It sounds dodgy to me. You should get it checked out by a professional to be on the safe side.

+2.

It really sounds that the house wiring is at fault and, like others said, get a professional to have the entire house wiring route check up before it is too late to regret.

thank y ou guys i ahev had a new dedicated ring main circuit installed with docs - so it can't be that

 

[Vladimir]

Have you tried pluging your gear through an AVR (Automatic Voltage Regulator with DC filter) instead of pluging it straight in the mains?

hi Vlad, thank you for your input.

no i have not tried that (I think). what exactly are they ? (I've googled it and a lot comes up)

I do use an extension lead with surge protection and filtration in it.

Ah nevermind then. You already filter the DC from the mains with your extension lead filter. That can't be the issue.