@MikeML

Please wake up

I guess I can expect that out of a Dalek

 

- it will make no difference, other than maybe replacing a safe cable with a dangerous one.

Now I´m worried. Why the cable is dangerous?Please explain, I don´t want to damage my amplifier!

 

You will not damage your amplifier - you may damage people.

Only a qualified electrician should work with mains cabling.

I am tired of this thread - I think I may stop posting on it

I enjoy the "exterminating" so much more

 

Only a qualified electrician should work with mains cabling.

You are right!Thank you for your advice!

 

I guess I can expect that out of a Dalek

Yes, sorry. I seem to be an especially grumpy Dalek today.

Our plans to conquer the universe still seem to be going nowhere and our leader has become Buddhist; and says we are to quit with the obsessive killing.

And the government have slapped a safety warning on my dome stating that "Daleks can damage your health"

... and somebody has wired up my mains lead wrong - my whole chassis is live and it doesn't-half itch this way.

 

You can exterminate people by having them touch you and another piece of audio equipment, then!

 

Shielded power cords are mandatory for most of the projects we do at work for two reasons, emissions and susceptibility. Emissions usually don't apply in consumer audio gear because they don't create much electrical noise. Susceptibility is real. High frequency noise from a failing flourexcent lamp ballast can get into the amp through the line cord acting as an antenna, squirt through a poorly decoupled power supply, and show up at the speaker terminals.

ak

 

Thank you all for your comments. Now I know what I have to do!

 

But not connecting the shield to the earth ground lowers the capacitance,no?

Yes it reduces the capacitance to ground but, as noted by others, that's of no consequence in a power cable. Two-wire zip cord will work just as well as any fancy, low-oxygen copper, shielded cable to carry AC power to your amp (in spite of all the gobbledygook the audio fanatics will try to snow you with).

 

Shielded power cords are mandatory for most of the projects we do at work for two reasons, emissions and susceptibility. Emissions usually don't apply in consumer audio gear because they don't create much electrical noise. Susceptibility is real. High frequency noise from a failing flourexcent lamp ballast can get into the amp through the line cord acting as an antenna, squirt through a poorly decoupled power supply, and show up at the speaker terminals.

And what about all the unshielded power cable in the wall? Shielding a few feet of wire from the wall to the amp will have little effect on the total amount of radiation picked up on the power line to the amp.

 

They got power conditioners for that. Last time I saw a glorified 500W class AB power amp that should be used to generate a pristine 230Vac power for your equipment. It was sold for about $25,000. I cant imagine the dumbness of people who actually buy such a thing.

 

Two-wire zip cord will work just as well as any fancy, low-oxygen copper, shielded cable to carry AC power to your amp (in spite of all the gobbledygook the audio fanatics will try to snow you with).

I have heard diferences between power cords. I allways prefered the standard power cord to other fancy cables, but this Lapp Kabel is very good too. And is a cheap cable!

 

I just put a, "Thanks" on AK and crutschow because motor whine and ballast noise can get into the power entry of the amplifier, but you can't do anything about shielding the wires in the wall, and they are a lot longer than the power cord. As AK pointed out, it takes two failures...build the power supply correctly and it will quench the nasty noise that can appear nearly anywhere in the power grid.

 

#12 is right...it's what's in the box that's going to make the difference. A good LC network and properly regulated/filtered rails will stop even some pretty grievous hash from showing up in your signal.

I don't like to get confrontational with audiophiles, but most beliefs that people can hear difference between different power cords, speaker wires &c. over short runs don't bear out in double-blind tests...at all! My earlier comment about a bent coathanger was only partially in jest...at least one double-blind test suggests experts in stereo equipment couldn't tell whether expensive cables or coat hangers were being used to connect to the speakers...!

http://www.engadget.com/2008/03/03/audiophiles-cant-tell-the-difference-between-monster-cable-and/

 

I've designed stuff for an "audiophool" that believes all guitar amps can only contain tubes. My favorite trick is to include transistors and op-amps. He hasn't figured this out in over 20 years!

Seriously, this guy thinks that if a fly lands on an aircraft carrier, you will be able to hear a difference in the sound of the ships engines. One argument we almost had was about cathode bypass capacitors I had to remove because they caused too much gain. I left them in the amp with the ground end still soldered and he worried that they were causing a difference.

 

Whew, I've done some work for folks like that. One guy was worried because my resistors were a different color than the ones in his hifi head. Mind you, he couldn't read the actual color codes at all.

Another guy had a guitar pedal with a weird op amp in it that had blown and he was bothering me so much I finally put an LM358 in it. What do you know? It worked, he was satisfied, and I never heard from him again...

 

My mains lead(or power cord) is 3*1,5 mm2 conductors for a 60 Watts amplifier!Do I have any benefits trading for a 3*2,5 mm2 conductors?Many of my friends believe is better, but I have my doubts!

 

A quick search tells me that it should be good for at least 10A, that is 2300W in a 230V system or 1200W in a 120V system. No need to go any higher for a 60W amplifier. Even a 0.75mm2 would do without any problems.

It seems that your friends belive that thicker is allways better. This is true with speaker wire up to some point, but having more copper on a mains lead for something that draws next to nothing will give you no benefits, and add pointlessly to the cost.

If you plan to use this later for some higher power amps in the 1kW+ range then I´d go for the thicker option, otherwise I dont see any reason to do so.

 

It seems that your friends belive that thicker is allways better.

Yes, indeed . Thank you for your answer, I will keep the 3*1,5 mm2