Again Pete you come from the 'solid professional engineering' background, like myself, you look at a problem, research possible solutions, find the best, then apply it, end of problem.

However Frank, you appear to skirt around these issues, not understanding the problems then go off on 'half baked' solutions.

To even suggest that a silver mains cable could reduce any background hiss on a line level amplifier is in itself complete nonsense. But to go on to suggest the Tripath amplifiers 'benefit more than most' is utterly absurd.

Now at normal listening levels, volume control at mid way, I can hear no background, no hiss, no plops no cracks and have never done so, but after reading your piece, I wound the control to full, that represents 10X voltage gain, and that represents 100X power gain, but again ear hard pressed to tweeter or mid unit I heard nothing, no hiss, nothing.

So prey tell me what improvements can I make to a system that has no 'background noise' at all.

Maybe I did design the power supply correctly in the first place, such that it eliminates any 'mains interference', any 'RFI', any 'EMC', to the point that on 'switch on' there is no hint of a click or pop, but that is what good design is all about.

I do listen to music on this system confident of the complete silence between tracks, the inky blackness between passages, I have NEVER heard any background sound that was mains born ever, no the only background I ever hear is the upstairs neighbours clomping around, and that is above my 85dB listening level, and they complain to me!!! 

If the equipment you use is so badly designed that every cable connected to it affects it's performance, then look for decent equipment, instead of trying to prop up it's lack of performance with overpriced and silly cables.

John...

PS What exactly is your equipment line up? 

Pete,

The problem with UPS is if you don't have the power available, you can squash dynamics. That having been said, I think battery is probably going to be one of the routes forward in conjunction with today's high efficiency amps. The Living Voice setup that they've been taking to shows is really just an expensive enhancement of that. Red Wine Audio is doing some really interesting work with battery powered amps.

High end OFC? There's actually not much of that that justifies it's name or is a good deal more effective than a number of varieties of bulk cable or particularly network cable. Possibly some of the Kimber stuff, the DNM cable and maybe and the odd other example. Pure copper tends to be a bit low end except in a very few cases (Audionote JP, Acoustic Zen, Kimber select etc.). If you were looking for something to make a difference, I'd probably start with an interconnect in the £80 -ish kind of area and upwards from someone like VDH or one of Frank's solid silver mains cables (which are actually the ones that I personally use pretty much throughout my system). Usually with high end, you're looking at silver plated copper or pure silver.

Shotgun style, QED79 type OFC cable is really outdated and only made a bit of difference anyway. A lot of the fuss surrounding it came about because in the 70's people were surprised that they could hear any difference at all. Articles decrying cables tend to concentrate on Monster cable which I personally am not at all keen on (very much IMO). A £30 interconnect from a mainstream brand will indeed often make only a small difference IMO which many may not regard as significant.

Some of it works & some of it doesn't. Some amps are terrible too - it works like that in every branch of the hifi industry. Things have moved on significantly over the last few years.

With mains cables IME, at the very low end of the scale for most popular brands, don't make a lot of difference; gains are principally comparatively small ones in noise floor and bass response. That can be different for some of the smaller 'cottage industry' brands who work on smaller margins and don't advertize. As you get towards the Nordost and particularly good solid silver designs, then things tend to come on in leaps and bounds.

Frank,

Actually Tripath/Icepower/Hypex/Nuforce type digital amps do indeed respond well but it's not hum/hiss situation that really improves. You do have to be a bit careful with them because they can go bright and clinical very easily so some or a lot of copper somewhere in the loom can sometimes be the best. Where they need help compared to something like a good valve amp is most often in imaging. Unfortunately, I still haven't heard any good news about Tripath's financial situation & their website doesn't seem to have had any news posted since 06.

Chris, i hear what you're saying re losing the dynamics on an undersized UPS and i do agree that a high impedance 'mains' supply will cause the same, particularly on the bass. However, there are some VERY big UPS's out there if people were that serious about their AC supplies. 

I still disagree that a mains cable over and above whats required to carry the current will make any odds though, the voltage drop is so insignificant in comparison to the variations in the rest of the supply chain and the internal DC regulators are (or should be) well able to handle it. I think one fact that even those know of the existance of voltage regulators fail to realise is that they are also responsible for removing residual ripple which the smoothing capacitors leave. They do this 100 or 120 times a second (50 or 60Hz supply), removing far greater voltage swings than would be introduced by a mains lead and no one even gives it a second thought.

If changing a mains lead is reducing hiss, then i can only think its due to the L & C of the lead (which would be minimal) filtering out mains bourne interferance, which has to draw into question the design of the power supply and with it the rest of the amp. Presumably it doesn't hum particularly badly, in which case its already sucessfully filtering out a 50Hz signal of 230VAC RMS (the mains). Any high frequency noise should be many orders of magnitude less than this and being of a higher frequency is much easier to remove from a dc supply rail. If the lead truly is removing hiss then i would imagine the power supply (a) Has no internal mains filtering of its own and (b) has no high frequency decoupling capacitors fitted. Large electrolytic capacitors are great for smoothing mains ripple, but lousy at high frequencies. It is good design practise to fit smaller non-electrolytic capacitors across the supplies to remove any HF components. I have to say, if (b) is true i would be very suprised but it is the only way any HF noise could get from the mains into the audio chain. If this is the case, then it also affects the amplifiers ability to pull high frequency currents from the supply, which i would expect to cause a degree of HF distortion and intermod. It also draws into question the suitablity of any capactors in the audio chain.

I will post my thoughts on interconnects later after ive eaten as it may take some time!!!

This discussion is going absolutely no where, as it has nowhere to go. Anyone who can hear a difference to a mains lead will do so irrespective of any scientific theories.

In the same way anyone who believes they can tell the direction of a cable will do so, even though it is patently obvious that a cable CANNOT have directionality.

Have now after some 297 posts on this site decided to look out for a more interesting topic.

John... 

Of course it won't go anywhere because of prevailing blinkered viewpoints and flawed logic from some quarters.  There isn't even the open mindedness to go down to a local hi-fi dealer and borrow some esoteric mains cables to play with. 

I also suspect that the "I'm an engineer so I know best" trump card isn't working too well either because I too have been very well educated in electronics. One of the first valuable lessons I learned is how to work logically and systematically through a problem, investigate all the variables, gather all the relevant evidence, then come to a conclusion.

Now there too is another interesting point . . . . . . I don't know and cannot recall anyone other than a magazine reviewer or a few daft cable vendors that actually claim cable directionality exists, especially with an AC signal.  I have certainly never experienced it, nor has anyone else I come into regular contact with experienced it either. 

Frank, 

Please dont tell me what i do and dont know about RF, i have been an RF design engineer and worked with RF amongst other things for the last 25 years.

If, as you say 'a mains cable 'filters out nothing whatsoever', presumably the same applies to speaker cables and interconnects. In which case how do you explain the claimed differences between them? After all, if its changing the bass, mid range or top end specifically then it must be acting as an audio filter of some kind. The values of L & C required to alter an RF signal are very very much smaller than those needed at AF.

Another factor which can affect RF pickup is the length and positioning of the cable. For instance take a nearby wireless LAN or video sender operating on 2.4GHz. This equates to a wavelength of approx 12cm, changing the length or moving part of the cable by as little as quarter of this (3cm) can make the difference between the signal arriving at the equipment at a voltage peak or a total null. If you think audio is tricky, try RF, thats how fussy it can be.

If sufficient level of RF finds its way into an audio chain not designed to cope with these frequencies it can get rectified by any of the semiconductor (or valve) devices. This in turn can upset the bias or present itself as a not particulrly stable voltage on the audio chain, either of which will cause noise. In the case of an AM transmission the voltage would vary with the transmitted voice which we would hear. Hence hearing taxi's etc in the days before FM.  If this happens in the small signal stages of an amp, the noise will get amplified along with the program material, hence the RF doesn't have to be enough to 'heat up your tooth fillings' or anywhere near it. I have seen particularly poor amplifiers lose the plot entirely with nothing more than a radio mic transmitting 10 milliwatts several metres away.

And yes, all other factors being equal, the hiss would be the same whether the cable is copper or silver.

Frank, i have never claimed that there was anything directional about any lead, fuse or anything like it, except for a p**s take over a claim of directional fuses one night.

Well then Pete, with no disrespect whatever to your knowledge, what are the LCR parameters that you can vary within a cable's construction and what are the result of those changes at human audible frequencies?  I see any cable as being merely an electrical hindrance to transmission at any frequency and all of them are in some way flawed. 

With regard to interconnects and speaker cables in a hi-fi system context, it is a case of almost pot luck which of the audible frequency spectrum the cable is going to corrupt.  Some alter the treble frequencies, some the bass, others attenuate the treble which gives a bass emphasis, some attenuate the bass which gives a treble emphasis.  It is only a very badly constructed cable that attenuates at all audible frequencies.  There are sonic differences between them despite what you say and generally speaking it is conductor metallurgy that provides the more profound audible differences. 

When talking about the MAGNITUDES of these perceived differences that is where the real argument begins. 

Up until now it was generally held that humans can only detect differences in sound levels with a continuous tone at a fixed frequency of 1 or 2db, but recent tests by Matrix Audio in Spain have revealed that blind tested listeners can detect differences in music replay as low as 0.3db.  Some of of the population nave a hearing acuity at that level but the majority of the population struggle to hear differences of 3db and more.  Go figure the rest.

Ok,

We are all entitled to our own beliefs and opinions as i have said before.

Chris, you suggested i trial some cables, I myself believe that decent cables are worthwhile but without going mad.

One of the things which has put me off high end interconnects is the obvious flaws in some designs, which in my opinion, make them worse than a standard one. For that reason i prefer to make my own.

For example Russ Andrews KCAG retails at £315 for half a metre. It appears to have three wires platted together and not even screened for starters. I could well imagine a screened mains lead would help to reduce hum in this case. It claims to 'Cancel RFI with this all-silver interconnect' Its an unbalanced cable, one side is grounded, it isn't even going to cancel mains hum! Its also got 3 wires connecting two phonos, so either one wire is spare or it has two wires in parallel which isn't good practise as circulating currents could be induced by RF or magnetic fields. The platted cable is liable to make it suseptable to handling noise and microphony if used with small signals. There is also the option for built in attenuation but no-where does it state what source and load impedances its designed to work with so how on earth can they give an attenuation figure. It also uses silver wire and teflon insulation, not theres anything wrong with either but in my opinion they are unneccassary. You already know my thoughts on silver conductors and teflon falls into the same category. We are not dealing with high voltages, hi frequencies or high temperatures so the only possible advantage it that whoever has the job of soldering the leads can be as cack-handed as they like without melting anything. IMO Russ Abbott could do a better job!!

This is but one example of some of the things i see, £315 for something that has so many glaring faults. It throws the credibility of the whole interconnect industry into doubt and frankly drives me away from anything to do with them.

Ok Frank,

Reference LCR etc. At the start you are asking what LCR parameters can be changed within the construction of a cable and state that 'I see any cable as being merely an electrical hindrance to transmission at any frequency'

Yes any cable is a hinderance at any frequency, a thin cable will exhibit a higher resistance and hinder all frequencies, its L will also be slightly higher. A decrease in volume will be noticeable if we are talking speaker cables here and possibly a very small amount of HF roll off due to the L. C is a function of the plate area and the spacing (assuming no change in dielectric), so in the case of a cable its basically the spacing (assuming round conductors). I'm not saying that a length of bell wire wont sound crap, but the frequency response differences in any heavy gauge cable due to L & C, whether it be silver or copper, would be minimal if any. 

Later on you say ' it is a case of almost pot luck which of the audible frequency spectrum the cable is going to corrupt.  Some alter the treble frequencies, some the bass, others attenuate the treble which gives a bass emphasis, some attenuate the bass which gives a treble emphasis.  It is only a very badly constructed cable that attenuates at all audible frequencies.'

I had to read this several times as you use the words 'alter' and 'attenuate' separately, each time in respect to bass and treble. You yourself agree that a cable doesn't introduce a significant frequency response in the audio range due to L and/or C so it only leaves R.

I'll deal with the attenuation first. You say that some attenuate the treble and some the bass. Where are you setting your datum here? Could it not be that the treble is more or less constant and it is just the bass that is dropping by differing amounts or vice versa?? This i could relate to cable resistance (assuming passive crossovers). The impedance of a speaker is not by any means fixed, it varies with frequency. If a passive crossover is used, the problem becomes even worse. If the speaker (crossover) is tied tightly to a decent amp then the low output impedance should be able drag the input of the crossover to whatever voltage is required at that particular time. In addition, assuming the amp has a decent damping factor, it will shunt any back emf, preventing the drivers from interacting. If, on the other hand, there is significant resistance between the two, the voltage drop across the cable will vary depending upon the impedance of the speaker/crossover at the frequency in question. The impedance of a speaker, especially one with a passive crossover varies wildly. This would account for your 'pot luck' factor.

Next the 'altering'. A cable cannot alter the frequency. A poor cable with high resistance would lower the damping factor and could cause interaction of the drivers (assuming we are talking about passive crossovers here). This could possibly produce intermodulation products at high volumes, causing extra frequencies to be present.

This is my logical explanation for what you're finding. It can all be explained purely by resistance values. Low resistance can be achived perfectly well with with decent copper cables.

Pete,

I understand that you mean well, and you do your very best to enlighten and educate people on this forum, but having now placed more than 300 postings I realize that such ideas are a 'non starter'. I have battered my head against a brick wall trying to explain the science as has Pluto and others, and all to no avail.

It is similar to trying to convince a Roman Catholic to become a Christian, it has nothing to do with reality, science or fact or truth.

No all are deep rooted convictions that are, what they believe is right, and no amount of 'evidence', 'scientific' or 'rational input' will change their minds.

However I do think the 'sound enhancing' placebo drug could change all that, and prove a few points, but anyway at worst it would be 'a good little earner'.

There are very many out there who would not dream to research a fact, in their cosy world, much easier to just ask a friend and completely believe the answer, after all I trust the friend, so I trust the answer.

If you want to find reasons and answers in life, you only have to look at history, and there are countless examples of this blinkered thinking, in science and in war, and particularly in religion.

However if you want to find 'popular opinion' then read the mags, watch the telly etc. and sink back in your cosy world of complete ignorant bliss.

No but if you want the truth, difficult as it is, you have to find it for yourself, not easy, often not what you expect, often deeply disturbing, but nevertheless the truth.

John...

you only have to look at history, and there are countless examples of this blinkered thinking, in science and in war, and particularly in religion. 

Well at least you acknowledge that you are blinkered John.  It doesn't bother me one bit to be honest and it's a waste of my effort scoring points in a silly debate with someone who is so entrenched in dogma.  You carry on thinking the way you do but please don't fall into the trap of believing that you are RIGHT. You have had 3 clear opportunities now to be open minded but you have rejected all three so I'm not prepared to offer any more of my valuable time when your best effort to reciprocate is to snipe and sneer.  The fact that you are not even prepared to make a small effort to be open minded tells me it is you that is terrified of having your beliefs shaken.

I watched a TV programme a couple of months ago where a woman cartographer during the war noticed that during the mapping of sea beds for submarine navigation charts there were clear signs of deep mid-ocean trenches.  She made the findings known and all the sceptics derided her endlessly saying they were sporadic readings, hallucinations, delusions, equipment malfunctions and saying it just wasn't possible.  The poor woman was almost destroyed by this huge onslaught of outright negativity from so-called "intelligent" men and attempted to take her life several times out of sheer despair and frustration.  It was some time later that someone else updating the sea bed mapping with improved sonar gave a clearer more unequivocal image and finally the sceptics had to grudgingly concede that the woman cartographer had been right all along.  From that obsservation we now know about continental drift, we now know that volcanoes are not sited where they are by accident and a whole host of other important scientific discoveries and if you look back across history you could find endless carbon copies just like that.  The facts remain the same, but it's the appalling BAD ATTITUDES that are the significant factor in the story and like I said I had a thousands years worth of lucrative earnings to be had from that mindset.

Pete, you say that "a decent cable" suffices for you then great.  The core of the argument has always been should hi-fi enthusiasts not use the 'freebie' cables given away with components at purchase and invest in a "better" aftermarket cable and your answer covers that subject well.  The debate then moves on to how much should anyone spend on an aftermarket cable and the magnitude of improvement in sound gained relative to the amount of money being spent. Yes?

I wholly agree that a certain cable vendor asking £315.00 for a half metre of plaited wire with a couple of RCA connectors isn't good value for a start and the actual perceived sound enhancement in situ isn't all that great either which matches exactly your technical appraisal of it's capabilities.  I wouldn't hold up this cable vendor and it's products though as a shining example of aftermarket cable manufacturing at it's best. 

Price is no indicator to the level of performance increase you anticipate in achieving - fact.  Cables with similar cable geometries and identical conductor metallurgy don't have vastly different sonic characterics.  Change the conductor metallurgy and the sound does change, so you can either agree or disagree as much as you like.  No matter how esoteric the metal cocktail is within that conductor, you will never achieve a "night and day" level of sonic difference - fact. 

Put into context, a cable is just another component in a hi-fi system chain.  I have heard differences in cables that equal a CD player or amplifier upgrade.  I have heard cables that sound dire, robbing detail and dynamics.  I have heard cables that act as low pass or high pass filters.  Once in a while though a cable comes along that does stand head and shoulders above the others.  None of them though have a "sound" in isolation, but how they interact with the system they are installed in and the listener that perceives it.  Put a £2,000 cable into a £100 system and you are going to be mighty disappointed.  Put a £2,000 cable into a £10,000 system and if the listener cannot hear that difference then a £10 cable will do just fine.

Regardless of any argument, from the point of view of those of us who have actually heard (often significant) differences as part of our living experiences, do you honestly think that we could be convinced otherwise? It's like telling someone that black is white and that their perception is wrong.

Presumably, we can leave it to you guys to tell us what we should be listening to?

Re; KCAG. I actually think it's not a bad design. It is however, more appropriate at £60 as <a href='http://www.homegrownaudio.com/hga/super_silver.htm' target='_blank'>this example</a> shows.

Quite right, well said.

 John...