Upgraded wall sockets

[DSJR]

Just getting a qualified electrician to check the tightness of all the wire fixings from meter to plugs (ring mains especially) would probably make as much difference as fancy sockets and of course, not all good gear is sensitive to mains issues anyway.

[Marco]

Hi Alan,

Pitty we cannot do a before and after with mains changes. Here's the new and revert back to before to compare.

As I outlined earlier, if you're keen enough and have an understanding electrician, it's quite easy to demonstrate improvements in "mains changes", as one goes along implementing them!

Also, a very quick and easy A/B comparison I can carry out at home, is connecting and disconnecting the dedicated earth for my system (fed from a serious of earth rods in my garden), as music is playing, and noting the easily discernible degradation in sound quality, whenever the dedicated earth is disconnected (with the system temporarily reduced to using the standard house earth), and the subsequent similarly easily discernible improvement, when the dedicated earth is put back in...

It's always reassuring when you can actually prove that you're not imagining things!

Marco.

[Marco]

Hi Dave,

Just getting a qualified electrician to check the tightness of all the wire fixings from meter to plugs (ring mains especially) would probably make as much difference as fancy sockets...

Perhaps, however it would certainly be a nice free tweak!

...and of course, not all good gear is sensitive to mains issues anyway.

I disagree. ALL audio equipment, no matter how well it's been designed, should benefit from being fed by a mains supply, the measured resistance of which, has been genuinely lowered by a significant degree.

Some of the sonic improvements others and I have heard when tweaking equipment, in that respect, have superseded that gained sometimes by upgrading to the use of a much more expensive amplifier!

Marco.

[prestonchipfryer]

Also, a very quick and easy A/B comparison I can carry out at home is connecting and disconnecting the dedicated earth for my system (fed from a serious of earth rods in my garden), as music is playing, and noting the easily discernible degradation in sound quality, whenever the dedicated earth is disconnected, and the subsequent similarly easily discernible improvement, when said earth is put back in...

Marco.

Have to say had similar experience. Even with my modest equipment the use of a really good earth is essential. The degradation in sound quality is obvious when the connection to my earth rod is disconnected, resulting in a quite bloated bass response and increased grain.

[Marco]

The degradation in sound quality is obvious when the connection to my earth rod is disconnected, resulting in a quite bloated bass response and increased grain.

Yup, that's *exactly* the effect you get!

Marco.

[Barry]

Hi Martin,

Yes, the Furutech sockets work and provide a notable sonic improvement, but they're really just for adding the 'icing to the cake', as it were, once every other aspect of your mains set-up has been sorted, therefore to be honest, your money would be much better spent on something else, like this if it's still available for sale:

http://theartofsound.net/forum/showt...797#post341797

Later, you could then upgrade the sockets for Furutech ones, as I have on my Mark Grant mains block. Correct me if I'm wrong, but I think the sockets on your current block are fixed?

If you really want to fiddle with wall sockets, then in my experience, the best sound-per-pound option is The Missing Link EPS-100 Ultrapure Silver plated (un-switched) wall sockets, shown here:

http://www.the-missing-link.net/new_page_1.htm

If you scroll down, you'll see some measurable proof of their sockets having considerably lower resistance than bog standard generic sockets from B&Q, or whatever, and even supposedly high-quality ones from MK! On the left is the measurement from the Missing Link socket, and on the right, one from from MK:





I've carried out those sorts of measurements before, with my friendly electrician, when we were optimising my mains set-up, and trust me you can hear the sonic improvements of lowered resistance!

Right down at the bottom of the page are prices, which I consider are very reasonable (considerably less than the Furutech stuff). I would also go for the matching 13A plugs, which are likely to be a good physical fit with the partnering wall sockets.

Try that, and you'll be a happy bunny!

Marco.

Oh dear - are we being swayed by measurements? I'm afraid to say that whilst to a novice those measurements might look persuasive, they are somewhat bogus.

The manufacturer has correctly used a milli-ohmeter using a four-wire method (to remove the effect of the resistance of the measuring leads themselves), where the wires at the measurement end are fitted with Kelvin clips. Unfortunately, to measure the contact resistance, he has simply pushed one Kelvin clip into the socket for the earth pin and the second (one supposes) pushed into the screw terminal on the back of the socket. The wall socket is designed to have the mains wiring terminals screwed tightly, and the earth pin will have a larger contact surface area than the Kelvin clips.

Kelvin clips are a bit like crocodile clips, except each 'jaw' is connected separately, contact is made when the jaws grip the device whose resistance is to be measured. To do the job properly, the manufacture should have used a 13A plug plugged into the socket, connected one of the Kelvin clips to the screw fitting of the pin and the second clip to a very short piece of wire fitted to the back of wall socket.

Even then his measurements could be subject to scrutiny. A simple one-off measurement of a low resistance value is usually insufficient. It is quite possible that the measurements could have been repeated with the opposite results. One should quote the mean value and spread over a series of measurements. Given the sloppiness of his measurement technique, a difference of 4 mOhm is not statistically relevant and has little meaning.

It doesn't matter that the earth connection has been measured, my criticism would equally apply to the live and neutral connections. If anything, the earth pin has a larger contact surface area than either the L and N, so the figures could be optimistic.

However the important measurement to be made is that of the mains source impedance at the wall socket. To measure the source impedance, one needs to measure the voltage drop of the mains under (a known) load. To do this is relatively straightforward, but unless you know exactly what you are doing, there is risk of electric shock. You cannot simply push the probes of an Ohmmeter into the L and N connections of the wall socket - you will destroy the meter, possibly causing it to explode.

I have made such measurements on the wall socket suppling my system and measured a source impedance of 0.2 Ohm. The N - E loop resistance is also < 0.2 Ohm with an open circuit 'float' of 0.25V (AC), 0V (DC). The mains voltage itself is 242V -243V with a DC offset of -18mV. These are good readings, well within requirement.

Incidently the source impedance measured at one of the sockets of a Belkin PF40 mains conditioner was worse: 0.33 Ohm.

I don't believe you need to use fancy mains sockets. I will accept that removing the switch can help, but provided the screw terminals are tight and the pins of the 13A plug are not heavily tarnished, there is no need to use connectors with exotic plating.

[Marco]

Hi Barry,

Thanks for the clarification, which is noted. You should, however, read my post #16, as it better outlines the point I was making earlier

Marco.

[YNWaN]

I must say that I am deeply skeptical as to the sonic advantage of 'hi-Fi' mains sockets.

[realysm42]

I must say that I am deeply skeptical as to the sonic advantage of 'hi-Fi' mains sockets.

Have you any experience of them?

[MartinT]

Gentlemen - all your music is effectively modulated power supply, which comes from the mains. Everything to do with power is critical and the more attention you pay to it the more the rewards. People with enormous understanding of power supplies, like Paul Hynes, make a living from selling you better quality power.

The argument that 'any properly designed power supply shouldn't let anything through' is bogus. It's all about pushing the noise floor down and removing distortion elements from the power rails. One of my most sensitive components to mains quality, and the one which responds the most to my regenerator, is my Chord power amp. It has a switched-mode power supply! One which reconstitutes smoothed DC from high frequencies.

So give your mains and power arrangements some attention. You will be surprised at how much goodness comes from small tweaks. Start with a can of Deoxit and spray the pins on all your mains plugs and IEC connectors. You'll be surprised.