The biggest PITA I had with CAT is the attached umbillical from the PS to the unit. I know other manufacturers use detachable cables for this, which is great. Just think what attached PC's would do.
The biggest PITA I had with CAT is the attached umbillical from the PS to the unit. I know other manufacturers use detachable cables for this, which is great. Just think what attached PC's would do.
Supposing you have all solid core copper 6awg into a 3 phase transformer right outside your home with less than 100 ft to your panels?
How is Mary Ann Mark? My regards to my compatriot.
Man oh man, how high is that??
High powered power amps when running at high power can create harmonics on the incoming power feed, and these harmonics can radiate to nearby power cords and interconnects and tubes and wood chassis etc that are not shielded (a lot of high end crap is like that believe it or not) and this then gets amplified and some folks claim to hear it. Also, some high end transformers in the power supply apparently are quite capacitive or other coupling effects due to huge diode surges and pass noise etc through to the power resovoir caps which can be quite large in value and series impedance at audio frequencies can be enough to modulate the active components...it really mostly comes down to urine poor design (and there is a lot of that in hi end audio too). You would, as Tim says, not expect to find poor design in hi end ultra high priced audio stuff but you do, and you find plenty here, that believe that price makes right. ha
I agree that a power transformer should not pass this stuff back to the line but apparently there is some real junk out there.
Above you wrote: "mostly comes down to urine poor design" !!!
Are you checking up on us to make sure we are reading closely ???
zz.
I have to assume that Ethan has never done any measurements whatsoever and is talking entirely off the top of his head
I am going to leave switching supplies out of the discussion; they add mucho' complexity but generally have many of the same issues. Unless that is the topic? In that case I would go a different direction than what follows, although ultimately have the same conclusion.
The line frequency is 50 or 60 Hz. Of course diodes, FETs, or whatever used in the power supply can switch much faster than that, but they are usually on the other side of a transformer (with relative low bandwidth). The amp gets its instantaneous current from the power supply capacitors; if the supply frequency is not high enough or capacitor bank not large enough to supply the demand then the rails will sag even if you have a superconducting cable. (Aside: I have played with superconducting microwave filters and they are pretty cool, pun intended!) Wideband current delivery and thus voltage spikes are related to inductance. Voltage spikes on the line are usually filtered as noise so you don't get EMI. And I still struggle with how 3' (1 m) of power cable can provide greater instantaneous bandwidth (voltage or current) when the other end is plugged into many feet of standard house wiring to your service box. That is not an ideal voltage source.
Diodes and power devices do not switch instantly and have their own intrinsic resistance and parasitic capacitance (charge storage). They can switch much faster than audio circuits, but a standard full-wave rectifier (or half-wave) conducts for a significant fraction of the power cycle. Not sure this is the place to get into device physics.
An under-sized power cord can certainly cause problems that anyone can measure, but I am struggling to see how an esoteric power cord can increase the bandwidth supplied at the wall outlet. It seems to me that will ultimately limit power delivery.
I am obviously missing what Atmasphere and others are seeing and hearing so will bow out of this. Should have stayed away longer...
I don't feel like listing credentials or the test equipment I have access to. I shall shut up.
Good day - Don
I guess you don't know much about me.I've been designing and measuring audio devices for more than 40 years. I've seen it all and done it all. Don explained it well: The reserves come from the power supply capacitors. Large electrolytic caps do the heavy lifting, and smaller bypass caps for the HF transients. I agree with Tom as well, but paying $1,000 for a power cord isn't going to solve that when what's more useful is a $30 Corcom RFI filter.
--Ethan
I guess you don't know much about me.I've been designing and measuring audio devices for more than 40 years. I've seen it all and done it all. Don explained it well: The reserves come from the power supply capacitors. Large electrolytic caps do the heavy lifting, and smaller bypass caps for the HF transients. I agree with Tom as well, but paying $1,000 for a power cord isn't going to solve that when what's more useful is a $30 Corcom RFI filter.
--Ethan
Wow! I guess that puts an end to questioning your credentials. Where was it that you had your electronics training?
Do you know of any tube amps with switching supplies? They might be more germane to the conversation. FWIW Don, I had really old wiring that desperately needed replacement in a house I lived in. Try as I might I could not hear any improvement with power cords in that house. But if I took some of the power cords over to my dealer a mile away, or to a friend's house across town the effects were easy to hear. As I pointed out earlier (twice or three times now...) ROMEX has very good properties but is not legal as a power cord. Most power cords don't perform nearly as well as ROMEX. I do recommend reading the link posted earlier (here is is again: http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm). There is plenty of technical information in this link that shows what is up.
Do you know of any tube amps with switching supplies?
The debate on credentials is ridiculous. People can have a fantastic knowledge on electronics and very challenging electronics instrumentation, but unless they fully know how to correlate the electrical performance of their amplifiers with its sound quality they will be of no help in this debate.
IMHO if someone considers from start that all decently measuring competent amplifiers sound the same and minimizes the role of the amplifier in the chain he will not be able to contribute in a positive way to these debates about the origins of the often called "small differences".
Quite right, that is why I have found that engineers in general (there are always exceptions) are unaware that there is not a good correlation. It requires a scientifically inquisitive mind to start trying to put the two together.
This is why when I hear people from the engineering side of the equation making statements like Ethan's I just shake my head because it tells me that they have very underdeveloped observational skills. Of course human's can be fooled but that is also bi-directional and I would posit that people like Ethan and the great Randi are exploiting the other side of the coin to develop reputations as "Myth Busters". You put people under stress to make a definitive choice and their discriminative ability often shrinks or disappears. Not a big surprise because most people don't do so well under stress. Ethan, IMO you exploit this also well known "characteristics" of human psychology claiming that there aren't differences but perhaps you even (deep down) hear them yourself.
Comparing double blind tests in audio is not the same as with pharmaceuticals.
What I **do** maintain, because I have measured it, is that power cords do indeed make a difference, one that is audible and measurable and by measurable we are talking easy measurements ... put up or shut up.
I've said this literally dozens of times: The only measurement that matters is at the output of the connected equipment. Measuring only the output of the AC wire is irrelevant. Since changes at the output of the audio devices are never shown, the burden of proof to "put up or shut up" is clearly on anyone making the claim. What do you have?
--Ethan
I've said this literally dozens of times: The only measurement that matters is at the output of the connected equipment. Measuring only the output of the AC wire is irrelevant. Since changes at the output of the audio devices are never shown, the burden of proof to "put up or shut up" is clearly on anyone making the claim. What do you have?
--Ethan
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