Is it necessary to use the same brand and model of power cables for the amp and pre-amp? Any thoughts about mixing and matching? I know it all comes down to how they sound, but would love to hear your inputs or tips to guide me in the selection.
williewonka My example of 5.51 amps for a 100 watt amplifier refers to full power operation. If you are operating with the volume control high enough that the amp is being driven into clipping on transient peaks you need a more powerful amplifier, and not a thicker power cord because you are asking the amplifier to whack that drum harder than it is able ;-)
geoffkait Re. Pop Quiz "
How come HDMI cables are directional?" They are not unless they have active circuitry built in to compensate for unusually long runs. ;-)
ron1319 Power cords are directional because one end is terminated to plug into the wall or power conditioner and the other end plugs into the audio equipment. I can’t remember ever seeing one that wasn’t.
I just measured the drop across the 5.5 foot original power cord on my 1964 Scott 222D Integrated Amp. and found it to be 0.2Volts [120.8VAC at the outlet and 120.6VAC at the circuit side of the power fuse. This is with 18guage lamp cord!
Why do folks insist that "Power Cables" need to have a bandwidth equal to that of a very high-spec amplifier’s audio bandwidth? Are you people INSANE? We are talking about 60Hz AC here! If your power cords are carrying Khz range signals or noise there is something horribly wrong with your amplifier that needs to be corrected immediately, if not sooner because you are essentially operating a Radio Transmitter in violation of Federal Law! ;-)
Power cords are directional because one end is terminated to plug into the wall or power conditioner and the other end plugs into the audio equipment. I can’t remember ever seeing one that wasn’t.
Really interesting that the article above says the wiring in the walls is usually pretty good.
My Levinson 333 has no option to change the power cord. I have wondered about running 30 amp service to it and swapping out the plug as specified in the manual. I wonder if the difference would be audible for high-transient situations.
I have a couple of different power cords and look forward to trying them once my Stellar GCD arrives next week.
Power cords: a 2V drop across a power cord can rob a tube amplifier of as much as 40% of its output power!
Ralph, could you provide a technical explanation of why that would be so? I don’t doubt your statement, but I’m interested in understanding why that would occur.
Re your other points, all of which strike me as excellent, I think that it should be stated that none of those points NECESSARILY mean, to cite an example, that a $2,000 power cord will outperform a $200 power cord in any given system.
Atmasphere 9-15-2010
Al, the reason a power cord can have this effect is simple. If there is a 2 volt drop in a power cord, the filaments of the tubes will run cooler and the B+ will be reduced. Since this is a voltage, the result is we get less voltage output out of the amp. Less voltage=less power. Depending on the amp this can be pretty profound. and I have seen it with my own eyes. I do agree though that that does not justify a $2000 power cord, but it **does** justify one that has decent connectors and conductors that will not heat up at all. That has to cost something, probably not $2000 though. One thing about audio is that if there is a phenomena, there is also snake oil for it.
Almarg 9-15-2010
Thanks, Ralph.
That would also seem to say that the value of the ac line voltage at each listener’s location can be a very significant variable in the performance of a tube amp (assuming it does not have regulated filament and B+ supplies).
Which in turn emphasizes how easy it can sometimes be for extraneous variables to lead to incorrect sonic assessments.
I think that the following lengthy post that was provided by Atmasphere a few years ago, in a post dated 6-3-2014 in this thread, is worth quoting here in its entirety. It reinforces some of the things that were said above by Steve (Williewonka), and by me earlier in this thread.
For those who may not know, Atmasphere (Ralph Karsten) is the owner and designer of Atma-Sphere Music Systems, which manufactures unique and very highly regarded audio amplifiers and preamplifiers. He is also, IMO, one of this forum's most knowledgeable, experienced, helpful, sincere, and level-headed members.
With power cords its all about voltage drop across the cord. Some of
that is at 60Hz, and some of that is much much higher- well above
30KHz-100KHz depending on the power supply in the unit with which it is
being used.
I've seen a 2 1/2 volt drop rob an amplifier of about
30% of its output power. The cord was rated for 10 amps, and the draw
was about 6 amps. This measurement was done with a simple 3 1/2 digit
Digital Voltmeter.
The more insidious problem is high frequency
bandwidth. The power supplies of most amplifiers have a power
transformer, a set of rectifiers, and a set of filter capacitors. The
rectifiers only conduct when the power transformer output is higher than
that of the filter caps. So:
When the caps are fully charged the
amp is able to play. As it does so, the caps are discharged until the
AC line voltage waveform gets high enough again that the rectifiers in
the power supply are able to conduct. Depending on the state of charge
of the filter capacitors, this might only be for a few microseconds or
it might be a few milliseconds. Either way, the charge is a spike which
has very steep sides- and requires some bandwidth to make it happen.
If
the power cord has poor high frequency response, it will current limit
on these spikes. This can result is subtle modulations in the power
supply or even a sagging power supply voltage.
Romex wiring found
in many buildings actually works quite well. So it really becomes all
about that last few feet and also how well the power cord is terminated-
molded cords generally are not terminated very well. If the ends of
your power cord get warm after a while, you know you have a problem!
This
can be measured, its quantifiable and also audible as many audiophiles
know. Anyone who tells you differently probably has not bothered to do
any measurements- please refer them to this post.
I can go into
more depth but this is it in a nutshell. Incidentally, Shunyata Research
is refining an instrument that does a more in-depth analysis of what
this is all about. At the link you will see that their tests essentially
confirm what I have said here.
Here’s the thing - Powerful transient signal demands - such as the crack of a side drum or the slam of a bass can draw significantly more power than the 5.21 amps sisyphus51 calculated BUT only for very brief moments in time. However, they do contribute to the reproduction of the realism of the music.
The standard power cable provided by the maunfacturer is not capable of responding to the immense demands of tranient signals. More advanced designs allow the conveyance of enough power in a timely manner such that an amp can perform up to its full potential and reproduce those transients more faithfully.
Monoblocks do assist in the dynamic reproduction of music because of their large transformers /power supplies, but it really depends on the amount of current actually drawn by the amp as to how effective a third party power cable might be.
Smaller components that have a smaller power supply will "generally" show more of an improvement in sound quality when a better quality power cord is employed
Components that employ Wal-wart power supplies will excell when their power supply is switched to something more substantial including a better power cord.
Also - the quality of the actual conductors used in a powercord will improve the speed of the reproduction of those transients - e.g. that drum will actually sound much crisper (faster) and the bass will have more texture and slam.
I prefer silver plated conductors because they are affordable and offer almost the same perofrmance as solid silver.
Then there is the geometry of the cable itself - this contributes to the overall clarity and imaging... - The standard geometry of three wires side-by-side - perhaps with a slight twist - i.e. "The Norm" - is the worst possible geometry to use - it’s worst attribute is - it s noisy. To improve performance companies simply rely on conductor quality to achieve improvements in sound.
- Braided cables are less noisy and offer significantly better dynamic performance than the standard geometry and will show discernable improvements on components with smaller power suplies
- the best I have tried to date is a helix geometry - where the neutral and ground conductors are wound around the live condcutor - they have an extremely fast dynamic response with very low noise characteristics that results in the most realistic repeoduction of music.
So to sum up - that cable that comes in the box will do the job - but very poorly in comparison to other cables and especially a helix cable.
Many others besides myself have tried the helix design on a variety of systems (i.e. solid state and tube) and all agree they provide a significant improvement.
If you really want your system to soar to new heights - also employ IC’s and speaker cables that also use a helix geometry.
Unfortunately - the Helix Geometry is not available in power cables from third parties - it is currently only available to those that do not mind a DIY project. But if you can use a screwdriver and a variable speed electric drill take a look at...
In answer to the question asked by the O.P. - the brand is imaterial - the geometry and other attributes of the cable is what makes for the best results
I was using a metaphor. According to Wikipedia: "A metaphor is a figure of speech that directly refers to one thing by mentioning another for rhetorical effect. It may provide clarity or identify hidden similarities between two ideas."
What are you trying to say, dlcockrum? I thought we were discussing the electrical requirements of Home Audio Gear? And do you actually believe that manufacturers of high-end audio gear are fitting substandard wiring to their products?
“Good Grief! Just use the power cords supplied by the manufacturer of your audio gear. That is all you need!”
Yes and always repurchase the crap OEM tires that your car’s manufacturer put on it at the factory. After all, they meet minimum DOT requirements. Economics played no part in the manufacturer’s selection. It is only coincidence that they are the cheapest possible option. So what if they significantly compromise the potential performance of your car.
Good Grief! Just use the power cords supplied by the manufacturer of your audio gear. That is all you need! --- Imagine you have a pair of 100 Watt Class A Monoblocs. Thats 200W. Now, at 30% efficiency for Class A that would come to 600W (a little more including input stage, etc). At 115 volts that comes to 5.21Amps! It would take 2300Watts of total power to exceed the capacity of a 20Amp AC outlet :-)
Power amps and preamps are of course very different in their internal designs, regardless of whether they are from the same manufacturer or from different manufacturers.
They also draw very different amounts of current through their power cords, of course.
And in most cases they draw currents which fluctuate very differently as a function of the dynamics of the music, fluctuating essentially not at all in the case of preamps, while fluctuating widely in the case of power amps operating in class AB or class D. Consequently they may have very different sensitivity to the bandwidth of the power cord.
They have very different internal voltage regulation, none at all in the output stages of most power amps; very tight voltage regulation in the case of most preamps. Consequently they have very different sensitivity to voltage drops that may occur in the power cord.
Power amps can generate significant amounts of high frequency noise that can be fed back into the power cord and affect other parts of the system, to a greater or lesser degree depending on the shielding, bandwidth, capacitance and other characteristics of the power cord. Preamps generally do not do that, and even if they do (perhaps due to digital circuitry they may contain) the noise would have very different technical characteristics than the noise generated by a power amp.
Given all of those differences, from a technical standpoint it can be expected that preamps and power amps will react very differently to power cord characteristics. And therefore cords from the same manufacturer would seem to be no more likely to be an optimal combination than cords from different manufacturers.
roberjerman"The capacity of humans for self-delusion is unlimited. Mr. Spock"
Mr. Spock is not a real person he's purely fictional but that you keep posting this "non-quote" here again and again as though it carries some truth, authority or validity shows that this fantasy person was right about delusion because you seem to be consumed by it!
If you are using a high power amp you should use a PC rated for use with high current components. Preamps and DAC's draw very low current and can use a 14 gauge (thin) cable.
Not necessarily. I’ve has great results with mixing Wywires w/Kimbers and use a Nordost on my CDP. I have moved my Kimbers out, not because they don’t sound wonderful but because I felt my system was getting too laid back and the Wywires brought back the PRAT but still keeping the openness of the Kimber PC’s.
If you are using two separate brands on your pre and amp switch them back and forth. My experience the better cable goes on the preamp, then source and lastly the amp.
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