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davedotco's picture
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RE: Mike, you are a brave fellow.

BenLaw wrote:

davedotco wrote:

TrevC wrote:

davedotco wrote:

TrevC wrote:

andyjm wrote:

mikefarrow wrote:

thanks for your input trevc !

when i swapped the free "kettle lead" cable on my intergrated amp for a much thicker russ andrews signature cable the sound improved in all areas but mainly in the bass output of my system which became louder/fuller (?)

this is apparently due to the lower resistance that this thicker cable has hence it supplies the amp with power more easily.

wether this is true/the actual reason, i wouldnt know - i just know that this mains cable performs better than the free one !

Mike,

You are of course free to believe what you like, but that mains cable isn't impacting the bass response of your amp in any way. 

At a stretch, under very contrived circumstances, changing a mains cable MAY make a difference to the the pickup of stray RF (it can act as an aeriel), and if the amp has been designed very badly, this may eventually find its way to the output and possibly increase background noise. Nothing you are going to do to your mains cable (apart from disconnect it) will impact the bass response of your amp.

The technical explanation:

Mains is AC, your amp runs on DC.  The mains waveform is a sine wave, 50 complete waves per second. This is useless to power an amp, it is the wrong voltage, and needs to be rectified and smoothed.

The power supply in your amp first reduces the AC voltage through a transformer. This is then rectified through a bridge rectifier.  Instead of an AC waveform going positive and negative, the rectified signal now only has positive going pulses, 100 per second. This is still useless to power an amp, and has to be smoothed by a storage capacitor to fill in the gaps between the pulses.  The following link has a good explanation of this and diagrams of the waveforms.  Scroll down to "Full Wave Rectifier Waveforms":

  http://www.electronics-tutorials.ws/blog/unregulated-power-supply.html

So, lets imagine that a bass drum kick comes along to be amplified, and it just happens to coincide with the point that the mains AC waveform is zero.  What happens?  The amp can't draw power from the AC supply, at this instant, there isn't any to be had. It draws power from the storage capacitor. The best analogy is to think of the storage capacitor as a bucket, the amp is fed from a hole in the bottom of the bucket by a steady stream, the AC waveform comes along from time to time to slosh some more water in the top of the bucket.

The point is that instantaneous power demands are met by the storage capacitiors in the power supply, not the mains AC waveform (how could it if it is zero?). The AC waveform supplies the AVERAGE power used by the amp, not the instantaneous peaks. The average power demand from an amp is very low, just a few 100's of watts at the most - even with very inefficent designs (most of the supply gets given off as heat, and doesn't find its way to the speakers) - your wife's hairdryer will draw many, many times the power of your amp.

So, how can changing the mains cable make any difference to the instantaneous power available in the amp to improve bass response?

It can't. 

 

 

Bravo. Now let's have no more of this nonsense.

Andyjm's explanation would be rather more convincing if he did not gloss over the one aspect of this debate that is known to make an audible difference, ie Radio Frequency Interference.

I have owned, in recent years, a Plasma TV and two dacs that have an effect on the sound of my system when plugged in and switched on, they do not even have to be connected to the system for this to occur. 

Whilst not formally qualified in this area I have hunted down RF problems in many studios, theaters and homes and radiated RF around a sysyem can be considerable, dropping off with distance. My plasma for example, in it's normal position on top of the equipment cabinet, was quite clearly audible as an increase in the noise floor on my system, quite obvious.

This is an area that has had very little attention, Paul Miller, did some work on this in the 90's, showing how equipment reacted in different ways to the presence of RFI, it was not at all complimentary to some products but has been somewhat swept under the carpet since.

If the RFI is airborn rather than being transmitted through the mains then it is possible that, in the critical area around the equipment, different mains cables could react differently in their susceptibility to RFI and this could be audible.

 

Erm, he was talking about bass response. Red herring.

 

The bass response was an example chosen to explain why the mains cable should have no effect an the sound of an amplifier.

The RFI issue is another example, in this case chosen to illustrate how, by rejecting high levels of RFI in the environment close to the equipment, a different mains lead might have an effect on the sound of an amplifier.

 

Which if it is a problem can be dealt with with a cheap ferrite core:  http://en.wikipedia.org/wiki/Ferrite_bead

Which does not alter the conclusion, that a different, shielded perhaps, mains cable might have an effect on the SQ. That the same effect may be obtained by other means is not the point.

I never suggested that after market mains leads were cost effective.

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RE: Mike, you are a brave fellow.

Fair enough, I'm pretty sure we're not disagreeing, just adding to what you'd said.

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RE: Mike, you are a brave fellow.

benlaw thanks for your input.

does this mean that a cable with a ferrite bead will sound different to a cable without ?

can the people who believe cables all sound the same reply to this ?

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RE: Mike, you are a brave fellow.

BenLaw wrote:

Fair enough, I'm pretty sure we're not disagreeing, just adding to what you'd said.

OK.

For what it is worth I have used Ferrite rings and find that sometimes they are quite effective, othertimes not....... :?

RFI can be a real pain in the rss, I have found the only reliable way to get rid of it is to locate either the source or the piece of equipment that is being unduly affected and get rid of them from your setup.

I had to take quite a financial hit on an otherwise fine Plasma TV for exactly that reason. One of it's particular 'tricks' was to knock my BT Homehub completely off line, I swapped to a Virgin system that despite a pretty generic modem/router was fine in that respect.

Couldn't get rid of the noise on the stereo though, so the TV was replaced.

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I own a number of Premium

I own a number of Premium cables and here is my 2 cents.

This is the experience I have had on the impact various upgrades have had. Note - for the speaker, Analogue and digital i went from entry level ones to fairly premium ones.

Speaker - Huge Improvement
Analogue Interconnect - Huge Improvement
Digital interconnect - Some Improvement
HDMI - Some Improvement
Mains Cables - Little to no improvement, However the Amps already have the Cyrus PXS-r power supply's which might impact on this.

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RE: I own a number of Premium

kmlav thanks for your reply - glad you read and understood my opening question !

 

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RE: cable sceptics give us your experiences !

Any good advice where to fit/not fit ferrite cores and how do we know if they are needed and do they always ned to be wound?

Yamaha V2065. MS Mezzo 5.1 Panasonic 42. Sony BD. Garrard 86SB. WD Live TV. SkyHD.

http://www.whathifi.com/forum/home-cinema/lounge-hc-signature-update-bass-traps

 

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Lets try to look at this

Lets try to look at this pragmatically:

1) Mains supply - it is self-evidently worthwhile trying to make this as clean as possible to avoid any mains noise getting into your system. If you have a particularly bad mains supply, maybe a house with very old wiring or you live in a block with a shared supply, then it might be worth spending some considerable amount cleaning it up. A mains conditioner, which is basically a low pass filter, close to your equipment should work for most people.
2) Source to amplifier cables - this should be an area to concentrate on because anything spurious that gets in here, or anything that distorts the signal, is going to be amplified. A good shielded cable with good connections is required. However for analogue signals we are talking about very low frequencies, <20KHz, so capacitive/inductive effects will be very small unless the cables are faulty. For digital cables it is hard to see how anything will make much difference because it's just a stream of "1s" and "0"s and as long as they stay distinguishable you can distort them as much as you like and it doesn't change the signal. (This is why digital media is so noise resistant.)
3) Speaker cables - the requirement here is for low resistance and good connections so that the signal gets to the speakers. As with source cables the frequencies are low so capacitive/inductive effects will be marginal unless the cables are faulty. If you live somewhere with very high levels of RF signals, maybe close to a transmitter, or you have high levels of mains radiation, maybe you are near to power lines, then potentially speakers cables could pick these up and feed them back into the amplifier. In that case you might need to take special measures.

Chris

Marantz PM8005 / SA8005 / KEF R700s / AKG K702

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RE: Mike, you are a brave fellow.

Broner wrote:

ask yourself again what the value is your personal experience.

 

Wow, you're right, personal experiences mean ABSOLUTELY NOTHING. Thanks.

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RE: Mike, you are a brave fellow.

davedotco wrote:

BenLaw wrote:

davedotco wrote:

TrevC wrote:

davedotco wrote:

TrevC wrote:

andyjm wrote:

mikefarrow wrote:

thanks for your input trevc !

when i swapped the free "kettle lead" cable on my intergrated amp for a much thicker russ andrews signature cable the sound improved in all areas but mainly in the bass output of my system which became louder/fuller (?)

this is apparently due to the lower resistance that this thicker cable has hence it supplies the amp with power more easily.

wether this is true/the actual reason, i wouldnt know - i just know that this mains cable performs better than the free one !

Mike,

You are of course free to believe what you like, but that mains cable isn't impacting the bass response of your amp in any way. 

At a stretch, under very contrived circumstances, changing a mains cable MAY make a difference to the the pickup of stray RF (it can act as an aeriel), and if the amp has been designed very badly, this may eventually find its way to the output and possibly increase background noise. Nothing you are going to do to your mains cable (apart from disconnect it) will impact the bass response of your amp.

The technical explanation:

Mains is AC, your amp runs on DC.  The mains waveform is a sine wave, 50 complete waves per second. This is useless to power an amp, it is the wrong voltage, and needs to be rectified and smoothed.

The power supply in your amp first reduces the AC voltage through a transformer. This is then rectified through a bridge rectifier.  Instead of an AC waveform going positive and negative, the rectified signal now only has positive going pulses, 100 per second. This is still useless to power an amp, and has to be smoothed by a storage capacitor to fill in the gaps between the pulses.  The following link has a good explanation of this and diagrams of the waveforms.  Scroll down to "Full Wave Rectifier Waveforms":

  http://www.electronics-tutorials.ws/blog/unregulated-power-supply.html

So, lets imagine that a bass drum kick comes along to be amplified, and it just happens to coincide with the point that the mains AC waveform is zero.  What happens?  The amp can't draw power from the AC supply, at this instant, there isn't any to be had. It draws power from the storage capacitor. The best analogy is to think of the storage capacitor as a bucket, the amp is fed from a hole in the bottom of the bucket by a steady stream, the AC waveform comes along from time to time to slosh some more water in the top of the bucket.

The point is that instantaneous power demands are met by the storage capacitiors in the power supply, not the mains AC waveform (how could it if it is zero?). The AC waveform supplies the AVERAGE power used by the amp, not the instantaneous peaks. The average power demand from an amp is very low, just a few 100's of watts at the most - even with very inefficent designs (most of the supply gets given off as heat, and doesn't find its way to the speakers) - your wife's hairdryer will draw many, many times the power of your amp.

So, how can changing the mains cable make any difference to the instantaneous power available in the amp to improve bass response?

It can't. 

 

 

Bravo. Now let's have no more of this nonsense.

Andyjm's explanation would be rather more convincing if he did not gloss over the one aspect of this debate that is known to make an audible difference, ie Radio Frequency Interference.

I have owned, in recent years, a Plasma TV and two dacs that have an effect on the sound of my system when plugged in and switched on, they do not even have to be connected to the system for this to occur. 

Whilst not formally qualified in this area I have hunted down RF problems in many studios, theaters and homes and radiated RF around a sysyem can be considerable, dropping off with distance. My plasma for example, in it's normal position on top of the equipment cabinet, was quite clearly audible as an increase in the noise floor on my system, quite obvious.

This is an area that has had very little attention, Paul Miller, did some work on this in the 90's, showing how equipment reacted in different ways to the presence of RFI, it was not at all complimentary to some products but has been somewhat swept under the carpet since.

If the RFI is airborn rather than being transmitted through the mains then it is possible that, in the critical area around the equipment, different mains cables could react differently in their susceptibility to RFI and this could be audible.

 

Erm, he was talking about bass response. Red herring.

 

The bass response was an example chosen to explain why the mains cable should have no effect an the sound of an amplifier.

The RFI issue is another example, in this case chosen to illustrate how, by rejecting high levels of RFI in the environment close to the equipment, a different mains lead might have an effect on the sound of an amplifier.

 

Which if it is a problem can be dealt with with a cheap ferrite core:  http://en.wikipedia.org/wiki/Ferrite_bead

Which does not alter the conclusion, that a different, shielded perhaps, mains cable might have an effect on the SQ. That the same effect may be obtained by other means is not the point.

I never suggested that after market mains leads were cost effective.

 

No mention was made by the OP of any sound interference  getting into the amplifier, so it's still a red herring. 

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RE: Mike, you are a brave fellow.

tear drop thanks for your input - glad you see the point i made in my reply to broner !

i'm also a venetian snares fan !

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RE: Mike, you are a brave fellow.

mikefarrow wrote:

and the thicker cable i currently use is stated to have a lower resistance which is claimed to help the amp draw the power it needs to create, as i have found, deeper bass etc

First to say I would not be as rude to tell you can not hear a differance, however i thought i world draw your attention to the above claim.

Kettle 3000 Watts around 12.5 Amps continious current for around 2 minutes.

Amp 500 Watts? 2 Amps at full pelt.

The standard cable is more that enough to supply the power for the kettle?

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RE: Mike, you are a brave fellow.

boggit wrote:

mikefarrow wrote:

and the thicker cable i currently use is stated to have a lower resistance which is claimed to help the amp draw the power it needs to create, as i have found, deeper bass etc

First to say I would not be as rude to tell you can not hear a differance, however i thought i world draw your attention to the above claim.

Kettle 3000 Watts around 12.5 Amps continious current for around 2 minutes.

Amp 500 Watts? 2 Amps at full pelt.

The standard cable is more that enough to supply the power for the kettle?

Yeah but if you use a better cable for the kettle your tea will taste much better, almost as if a veil had been pulled away from it.

Chris

Marantz PM8005 / SA8005 / KEF R700s / AKG K702

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RE: cable sceptics give us your experiences !

There are five transmitters all within 1/2 a mile (or less) radius where I live...I kid you not!  A few years back I noticed that our kitchen weighing scales went mad for no apparrent reason and started weighing imaginary stuff...shooting up and down on the display. I thought they were just faulty so replaced two sets and then got a different make the third time round before working out something else was going on. What was even more worrying was the microwave oven also caused the same effect when it was on. So I've been walking around indoors with my tinfoil hat on since then (no, noooo, I haven't...) thinking it was only my brain that need shielding, but it looks like I'll have to wrap my hi-fi cables in extra thick tinfoil as well now. :grin:

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RE: cable sceptics give us your experiences !

professorhat wrote:

andyjm wrote:

What else would we post about? The weather?

Not great at the moment is it? Mind you, just came back from honeymoon in Europe and in Rome and it tipped it down on Monday. So.

 

Hi Prof  :wave:

A little ray of light in a sea of frustration........Congratulations.  :cheer:

"We should no more let numbers define audio quality than we should let chemical analysis be the arbiter of fine wines."  Nelson Pass

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