If the earth part of the mains cable is a route by which the signal can travel (less resistance than the interconnect) then the cable becomes a part of the sound circuit. However if there is "ground lift" then the cable becomes unimportant. But ground lift is seldom implemented since parts cost money. I always implement ground lift.
I'm fairly certain that Kimber do not sell mains power cables because of concerns regarding UL certification. Like all certifications (internationally) what is certified has to come with a build file, and hence the certification is for that product and that alone. And you have to do that with each product. So if you say manufacture 10 different mains cables, that is ten certifications and ten times the cost. So a total of $50 - $100k. And then if one or more fail, you do corrective actions and resubmit. It is a money pit. If later you want to upgrade the product (wire and/or connectors) you need to recertify. If you are real lucky, the certification body will accept that the change to the product does not compromise the approval and will simply change the build file. And send you a bill of course. Been precisely there with European CE approval of a pollution sensing product. I almost had to put a variation of that through ATEX approval for installation in an oil refinery, but managed to dodge that particular bullet! ATEX makes UL/CE look trivial by comparison.
I really hope that you mean lifting the signal ground from the chassis, not lifting the safety ground?
Signal ground, cannot add a document here. But basically a 10 Ohm, 5 Watt resistor parallel to a 100nF capacitor and parallel with a heavy duty bridge rectifier. More than 1.5 Volts and everything goes through the rectifier. Need to cater for some mains short being addressed. (chassis is still directly to safety ground, the circuit is through the ground lift) edit: http://www.valvewizard.co.uk/Grounding.pdf (page 276)
Russ Andrews in the UK has been selling Kimber cable based power chords for years (as well as cable for power circuits). I'm not convinced to this day that any of them comply strictly with UK electrical standards.
Yikes, I retract my "not insanely priced" comment. I was looking at the MusicCord model which seems reasonable enough for the product described. If they enhance your musical enjoyment, that's what matters most.
OK - I see what you're doing. Good that the safety ground is not compromised. Krelll power amps used a chunky 10 ohm wirewound resistor - no capacitors or diodes. I like the diodes in particular to pop a fuse if there is a large current tries to flow. I get around the whole hum and buzz problem by using balanced connections throughout. Plug and play, imperceptible hum and buzz with an ear pressed to the speaker even with moving coil cartridge selected at a volume setting which is challengingly loud with music at the listening position. That is why recording studios and live music use balanced I/O - they can't afford the time to frig around chasing buzzes.
I'm fairly certain that all RA's mains cables are PAT tested and stickered to that effect before shipment. To date they seem to have shipped 65,000 (from their site) of them over the decades without problems.
Balanced connections are in a different category than consumer electronics - hard to do when using an iPod or computer as source. There are also in-line insulators but I am not convinced it is a sound solution as I've found that not all consumer electronics is earthed properly (e.g. CD players with a 2 core mains cord).
I agree entirely that most consumer electronics is single ended, and there is clearly a problem with iPods etc as music sources. I have the benefit of designing or modifying my own gear, including a balanced phono stage (that is the thing that is entirely hum and buzz free). The main reason that consumer gear is single ended is clearly because of cost. And that is a pity, because getting an acceptable result (when hum and buzz is less than the hiss level) is a bit of a lottery, or downright impossible, with single ended. Whereas with balanced you just plug everything together and job done. Like most things you have to do it *right* of course! The main steps in getting an acceptable result with single ended is (a) keep leads short (b) use a lead with as low a resistance screen as possible. As an example Belden 8241F has a 95% coverage screen with a resistance of 2.6 ohms per 1000 feet. So if you have a 3 foot cord the screen resistance is 7.8 milliohms. You have to add to that the contact resistance of a phono connector at each end (typically 3 milliohms times two) to give 13.8 milliohms, ignoring internal wiring in the amps. Typical ground loop currents might be around 300uA rms, giving a hum and buzz voltage of ~4uV rms. So if the nominal signal level is 1V rms that give a signal to buzz ratio of -108dB - which is perfectly acceptable and you won't notice at listening distance. Keeping phono contacts clean and low resistance is a given. But if you take a signal level of 300uV from a MC cartridge you get a S/buzz ratio of -37dB - which is far from acceptable and will drive you nuts to eradicate. By the way, things with a 2 core mains lead are double insulated and have no earth connection. If everything in an audio chain is double insulated (which alas is rarely the case) it is much easier to defeat hum loops.
I find it amusing that 40 years ago most people were making the same arguments about speaker cables - that there’s no difference and that some cheap strip cord is enough. There are still skeptics but so much fewer than back in those early days. Most people now realize that there a huge difference in speaker wires. Now we start this all over again with power cables. That means it will likely take another 20 - 30 years before the mainstream figures it out one way or another. I haven’t experienced it myself yet but at least I have an open mind for the possibilities of it sounding better. I will go buy one and see for myself. The skeptics out there should do the same...
Not skeptics, just people who haven't bought into 40 years of continuous marketing of companies trying to sell overpriced cables. And not so much fewer, just the majority who carry on using what works for them without getting dragged into Internet forum arguments.
that is kind of the thought, a buy it and try it mentality to see if it sticks. i recently did this and the sound quality was worse, so i believe they can alter the sound. the experience also convinced me that my amplifier sounds spectacular with the stock power cable. just one user's experience and point of reference.
Similar experience here too. Not that it sounded worse, but I don't discern a difference, good or bad. But I feel similar about speaker cables too, my BJC are fine, well made, no issues that I can tell. But i don't have a big buck system either, so maybe the subtle differences from cables are just irrelevant for my situation. Eventually as I upgrade components, I might try other wires to see - open mind, that sort of thing. You never know.
For what it’s worth, whilst I remain sceptical about the difference expensive power leads can make to audio quality or detail, I am dipping my toes into the water with a couple of used but perfect Audioquest NRG-X2 leads. Mainly, I have to say, as a way of making sure that the leads that came with my audio equipment are of decent build quality, rather than for an “improvement”. However, I’m hoping to be proven wrong and hoping to see a discernible difference. I’ll update with my findings...
I tried Russ Andrews Yello mains cable. I failed to hear any difference. 2 colleagues also failed. According to Russ, I have to change mains Extension, use purifiers and interconnects to hear a difference. Meanwhile he gets richer and richer. £30 for a " superfuse". Its obvious to me.
Just a historical perspective, which, I'm sure, has been pointed out many times in this 3 year old thread: this "hubbub" began around 1998. It'd been happening for over 20 years by the time it reached certain levels of people learning that "accessories" actually can - and do - improve a system. I bought my first power cord, an MIT power cord, around 1999...
The fact that this has been talked about for 2 decades yet there is no empirical evidence to point towards the utility of power cords to improve sound is tell us that there's nothing here of consistent significance. Of course, like with anything, a number of folks would disagree and have idiosyncratic opinions. I think that's a minority... Otherwise every DAC manufacturer and amplifier manufacturer would be weighing on the best power cable recommended for their gear; if not just ship the product with the "best" cable to optimize the device.
Everything makes a difference. It's up to you to decide if the difference is better and worth the cost.
There is a ton of empirical evidence showing the improvement that AC cables make. Look at the Shunyata Research technical pages and their videos.
Of course the manufacturer of the power cord is going to come up with their own "research" indicating that their product is the best. In this case, Shunyata created their own proprietary analysis system ("Dynamic Transient Current Delivery") to provide the desired results. The best that a journalist who was invited to witness it could say is "Even if I didn't believe in the sonic efficacy of power cords like those Shunyata Research makes, the DTCD Analyzer is certainly measuring something that varies from cord to cord". This was back in 2010, and in the 11+ years since then, no one has been able to independently verify DTCD and whether or not it has any correlation to audio performance. The Audio Beat -A Witness to DTCD ; Shunyata Research DTCD Analyzer
