Power Cords

[Guest Bret]

Somebody call the men in the white coats who fit the jackets you wear backwards. I need a rock and roll doctor.

I have spent most of my "audio life" making fun of audiophiles. I love the sound of a half-speed mastered or Japanese pressing of a record as much as anybody, and sure, you really can hear the difference in 12 gauge wire and 18 gauge on a "big" amplifier playing big-bass recordings, but when I see ads for $250 amplifier power cords I just sorta smile quietly to myself and marvel at how right PT Barnum was. . . "This way to the Egress."

So this friend of mine who often remarks, "The experiment continues," just for funsies picked-up one of these high-performance power cords. He got it used and cheap figuring he could always resell it for at least its purchase price. The "equal-fool" theory.

I "defied" anyone to be able to hear the difference in a 1 meter power cord connecting an amplifier to the wall socket at the end of a 100' run of Romex from a cheap circuit breaker being fed by a supply that browns-out every time the neighbor's A/C cycles on. I laughed. I grinned a lot. I issued great proclamations and expressed opinions, and gave sound reasons why this pursuit of a better power cable was foolish; after all, by the time the AC gets trough the transformer, the caps, the amp circuits, the final outputs, and down the speaker wire it can't possibly resemble the AC out of the wall. That's what all that stuff in the amp is for!

Thinking that it even might be possible to hear a POWER cord is just lunacy; pure and simple lunacy. "Morons! Maniacs! Brain-baked acid heads having flashbacks hear this stuff. Naive and gullible innocents might "buy it," but then they sit in pumpkin patches waiting for "The Great Pumpkin," too," I suggested to myself.

In a blind test, where I had been "set-up" and predisposed to hearing no difference by a multi-layered lie, in which I did not know which power cord was which ->

On "hearing" the expensive power cord for the first time (not knowing which cord was which, remember), without anything BUT the power amp's on/off switch and the power cord being touched, within three piano notes my first impression and the first words out of my mouth were, "I'll be damned. . ."

Now, my friend says he can hear a difference in the dynamics of a single note. I cannot. I'm sure he can hear it, or believes he can, but I cannot. What I could hear, very clearly, was a blackness before and after notes. The note just appears out of nowhere and decays into nothingness. It’s a palpable nothingness. There’s so much nothing that the nothing was really something.

If I were to try this test listening only to a forte passage of Berlioz's Requiem I'd just about bet I could not tell any difference. Listening to "Cat Scrath Fever" would likely be another fruitless test, but listening to this solo piano was fruitful. Definition. Amazing.

So there must be *something* going-on with these cables. It's going to take a surgeon to remove my foot from my mouth.

Go ahead, tell me I've lost my mind because I'm already pretty receptive to the idea.

Bret

[soundminded]

Short of an independently verified Double Blind Test, I wouldn't believe my own mother when it comes to claims made for audio cables, especially power cords. Sometimes the mere act of removing an oxidized cable or one with a slight oil film on it and replacing it with ANY other cable will make an improvement. Many tests in audio are fatally flawed for one reason or another. And as for testimonials, I have never seen an audio product which did not have the most glowing endorsements possible from someone including at times famous celeberties. Most preposterous of all are the claims which have one cable "blowing another one away." Among the handful of people who argue this seriously, they admit that at most, the differences are subtle and can only be heard by some people with some music on some equipment. Nothing personal but I'm just not buying it.

[Guest rickcee]

OK i'm gonna bring this up -

mid '80's Stereo Review ran an article - blind test of several very different amplifiers ( 50 w mass prod. Pioneer reciever to thousand dollar tube types) and . . . drum roll ( or firing squad)

given modest volume levels as as not overload sharply -- statistical result - no one could reliably tell difference.

[Guest rickcee]

I looked up article, too late to edit --

Stereo Review Jan. '87

total result - 772 trials, 388 correct choices.

2 samples : Pioneeer reciever ($220.) v. Levinson amp ( $2000.) - 4 correct of 16 choices.

Futterman mono tube amp (2 @ 6000.) v. Hafler solid st. amp ( $320.) 28 correct , total of 48

Myself , I admit my ears are blown ( maybe front row at Dead had somethin to do with that ?) can't hear over 12,000 hz on test CD with headphones. Yes I can hear differences in my spks - the Dyna 25s sometimes seem to have a midrange 'problem' maybe age, need new caps ? The Koss are 'livlier' than AR. maybe the AR 302 just needs an amp with 4 times the power of my NAD 80 w / ch reciever . . . but I don't listen loud often, probably never over 95 - 100 db. ? ?

sortof interesting argument, anyway. Oh, I like the visual style of my KLH 17 best, that's why I bought them. sometimes think of getting good used 'small Advent' and putting them in the KLH cab., virtually identaical cabinet volume. Rick

[soundminded]

My experience is that there ARE audible differences in audio amplifiers although they are usually far more subtle than the differences in loudspeakers. I attribute most of the differences to frequency response differences. The test method invariably uses a connected 8 ohm resistor to the output. Real loads presented by loudspeakers are a different world. Not only are they usually highy reactive with widely varying phase angles at different frequencies, they are not even passive. The most massive poorly damped woofers with large magnets will have the highest back emf. Besides the differences in signal circuit topology, there is the power supply. I have always said that you cannot build a first rate amplfier with a second rate power supply. If you want to get an idea of how good the power supply is, just lift the amplifier up. The power transformer is the single heaviest and most expensive component in most amplifiers especially solid state amplifiers. Also the most critical.

There is no doubt in my mind that most vacuum tube amplifiers have a distinct sound of their own attributable to the distortion introduced by the output transformer. This is the source of much of the frequency response and non linear distortion rolling off at both low and high frequencies and tempering to some degree the shrill sound of so called audiophile loudspeakers. This distortion is orders of magnitude greater than on most solid state amplifiers. I don't believe that the vacuum tubes themselves have any particular audible characteristic based on listening to the NY Adio Labs/ Futterman output transformerless design. However, designers of early solid state amplifiers had a great deal of trouble correctly biasing class AB amplifiers to eliminate crossover notch distortion absent in well designed properly adjusted tube amplifiers. There were exceptions but when power MOSFETs largely replaced bipolar output transistors, the issue became moot. I personally have replaced my bipolar Dynaco Stereo 120 which blew up after more than 20 years of reliable service with the Klaus/Peterson Mosfet120 (60 wpc bridgable to 250 mono) which sadly is no longer available. At $200 for a box of parts and 7 hours work ($300 assembled) it holds its own with the best of them and can drive my AR9s to enormously loud distortionless outut in my 4000 cubic foot room. (It was available from Sound Values also known as SoundValves which bought out all of the old Dyanco spare parts stock.)

One of the worst ideas to come along in recent years IMO is the trend towards not using negative feedback. When improperly used, negative feedback can be a disaster resulting in instability or even spontaneous oscillation. But when used properly by designers who know what they are doing, not just tinkerers, this not only flattens and extends frequency response but substantially reduces non linear distortion. It also stabalizes performance. Amplifiers which do not use negative feedback can have their performance drift all over the place. Peformance can be affected even by temperature, especially for vacuum tubes. And as the tubes age, the changes in their thermionic characteristics are not compensated for. Unregulated power supplies also add to the instability of amplifier performance. Where the rubber really meets the road is when you hook up a difficult load like an AR3. Very low impedence, low efficiency, and requiring power bandwidth extended to the low end of the audible spectrum to perform their best, they can make lesser amplifiers event today, wilt and die. Likewise electrostatic speakers. Considering the configuration of an AR1W and a Janzen electrostatic tweeter and there is one tough load to handle.

It seems to me that in most home installations, a 100 wpc amplifier is adequate assuming that you are talking about an honest 100 watts of distortionless power over the entire audio bandwidth. Under those circumstances, most listeners in most situations would be hard pressed to tell the difference between one fine amplifier and another.

[Guest Bret]

>Many tests in audio are fatally flawed for one reason or another.<

I agree.

Okay, let's take a good amplifier "x" and a preamp "y" worth $$$$$ and a mass-produced Pioneer receiver. Now let's share a source, say a Grado green with a preferred input impedance of 10k and use shoddy interconnects between the bad switcher and the gear; let's take these two setups and run them through lamp cord to a pair of . . . oh, 3a's. Now let's play a particularly squeezed '74 Crosby, Stills, and Nash recording of piano and voice and let's play it at 93db.

Voila! Nobody can hear any difference! Wow. Now we've proven what? I think what we've proven is that in a test where you've squeezed-out the differences, no differences can be heard.

I've got a Sony DVD/CD/MP3/SACD, etc, changer. It has multiple outputs. I have a Sunfire Symphonic Reference preamplifier with two "Aux" inputs and a remote control. I took the friend's MIT super-duper cords and a pair of Radio Shack gold ended cords and connected both to the preamp.

We A/Bed going from one input to the other on the preamp.

Guess what? There was almost no difference at all, and it was a real struggle to hear what differences there were. In fact, I asked him to pick out the expensive cords. We listened to Supertramp, Yes, ZZTop, and I think it was CS&N, ah, and Michael Hedges playing his "harp guitar." In every single case of fuzz guitar or loud busy stuff he chose the "cheap" cords as being "better." And in each case where we had a solo instrument he chose the expensive cords. Every single time.

So we came to the conclusion that spending $300 on an interconnect was folly.

But I wasn't finished. I went and bought "Y" adapters and we did the same thing using his Rega Planet as the source rather than my changer. There was a huge difference in the interconnects this time. Huge. And the more expensive ones were better, no question. Was it the introduction of a "Y?" Was it the output impedance of the Rega? Was it something else? We don't know.

So what conclusion could we draw from that? That the Sony's output was so bad that the differences weren't in evidence? Well, maybe.

The conclusion, in absolute terms, is that under the right circumstances where the differences aren't there to be heard, you really can't hear any difference. Change those circumstances and you really can.

To further muddy the waters - some things don't make any sense. The power-cord issue; On the amplifier it makes a universal improvement. A second cord connected to the CD player makes an unpleasant difference.

So let's go back to my original post for a minute and your original response. I agree you probably shouldn't trust me as much as Mom and you say you wouldn't trust her in this case. (Now how can I compete with that?!) But really, truthfully, anyone can hear the difference. . .well, unless their hearing is particularly bad.

But here's where you have an absolute point: Take me from the room, subject me to murmuring for thirty minutes, bring me back into the room, play something, and ask me to tell you which cord I'm listening to. I'm very unlikely to be able to do it consistently. That doesn't mean the difference isn't there, it just means we've designed a test to defeat my ability to tell.

I don't believe that means anything meaningful, either. A pair of Bose Acoustimass cubes and sub-honker sound pretty good if you have nothing to compare them to. Does that mean that after a month of hearing murmurs I couldn't tell if I were listening to a Bose setup or a pair of AR-9s? Of course not, but how close does it have to be? Maybe AR-17s and AR-14s?

If those tests have real merit, wouldn't that mean that any incremental improvement in sound should be ignored because we can't remember the difference we heard after a few minutes and so "good enough" is good enough?

Bret

[Guest lmrosenthal]

Hiya Bret!

What an interesting post.....

You made several comments:

"...Now we've proven what? I think what we've proven is that in a test where you've squeezed-out the differences, no differences can be

heard."

and when discussing the test w/the Rega:

..."So what conclusion could we draw from that? That the Sony's

output was so bad that the differences weren't in evidence?

Well, maybe.

The conclusion, in absolute terms, is that under the right

circumstances where the differences aren't there to be heard,

you really can't hear any difference. Change those

circumstances and you really can."

Here's my thinking on this. It comes down to how clearly you system resolves the details of the music - resolution some people call it.

In my system, it's not very resolving of tremendous inner detail. I've got a NAD C541i CD player, a Marantz DV6200 DVD player, a Dual CS622 turntable w/Grado Green cartride, a NAD C350 integrated amp and a pair of AR3a speakers. Up until a couple of weeks ago, I was using an inexpensive solid state phono pre-amp (Btech, built similar to a NAD PH1) into the NAD C350. It sounded fine to me. Last year, I made the decision to gradually transistion to all tube gear. I figure it would take me 3-4 years to do this. First off, I purchased a Bottlhead Seduction phono preamp. It uses 2 6DJ8 tubes. I built it from a kit (a great experience, by the way), tested the resistances and voltages, and then fired it up. With no break-in, the difference in sound quality was enormous. I really couldn't believe what I was hearing. Great detail, beautiful music, great dynamics, bass, mids and treble to die for! All this for a $225 kit. To me an amazing value. But here's the thing. I could clearly HEAR the difference it made in my system. Whereas before, I couldn't tell the difference between interconnects and speaker cable, or between my relatively inexpensive CD player and a friend's $$$$ Wadia CD player, changing the phono preamp made a huge difference. I don't know why either.

Here's another interesting thing to me: The kit came with Sylvania 6DJ8 tubes. I called Upscale Audio for a couple of extras. In talking with Kevin Deal, he recommended some Electro-Harmonics 6922's (a drop-in replacement for the 6DJ8's). Ok, yesterday I decided to switch from the Sylvania's to the Electro-Harmonics. There was a distinct difference between the two. The Sylvanias had a better mid-range, but the EH's had better bass and treble. The point is, with my decidedly mid-fi system, I was able to hear the differences bewtween the two different tubes. Again, I don't know why, but I'm very excited that I can.

Note: Power cords? Never tried different ones. Interconnects? Cheap Kimber cables. Speaker wires? Homebrew, and very cheap. I always felt that my system (and my 54 year old ears) wouldn't be able to hear differences between the $ and $$$$ varieties of cords, interconnects and cables.

regards

Larry

[soundminded]

There are many things in audio that are difficult to measure and even more difficult to interpret. The power draw of an amplifier or any other component isn't one of them. In fact it is one of the easiest to characterize and understand. The applied voltage is measurable to great precision and accuracy. So is the current draw, the frequency, and the harmonic distortion. Any deviations from a pure 60 hz sine wave such as noise, parasitic rf or any other anomoly can be completely characterized and quantified. It's effect on the dc bias voltages and filament heater voltage can also be precisely measured. On another board, I presented the calculations for two 6 foot power cords one made out of #14 wire and one made from #8. With a 10 amp draw, the smaller wire suffers less than a quarter of one volt drop. Any amplifier whose sound would change with that kind of voltage change wouldn't be a very good amplifier. The things that might make amplifiers change performance with slight changes in applied voltage and current draw are the same things that make them awful designs in the first place. No negative feedback in the gain stage circuits is top on the list. Lack of a regulated power supply is another. This is especially true for vacuum tube amplifiers where voltage change not only affects the bias voltages but the temperature of the tubes making dependence on voltage even greater. One obvious measurement flaw that is easy to make is that if you measure an amplifier comparing different power cords, you should measure the temperature of the tubes or even transistors as well. Amplifiers lacking negative feedback are not stable and many factors including tube aging will drastically change their performance over time. Even from minute to minute as they warm up or cool down. There are a lot of people building terrible "high end' audio amplifiers out there who shouldn't be allowed near a soldering iron.

[Guest Bret]

> The power draw of an amplifier or any other component isn't one of them.<

I just got lost. Never in my wildest imagination did I suppose that what I was hearing was due to a choked current availability. In fact, it was my guess that we were experiencing problems caused by RF or other noise in the line, but I have no way of testing that.

Something that you said is very, very interesting. You said that RF and other parasitic noise would effect the way the amplifier works (talking about bias). So, in theory a power cord that filtered-out RF and a power conditioner to give you a good 60Hz sine wave would be really good things?

Bret

[soundminded]

I expect the power supply to do a far better job of filtering out rf than any power cord ever could. I'm amazed at the little ferrite rings some people are using. IMO, it is dangrous and illegal to put them on the ground conductor because it creates a high impedence ground effectively ungrounding the appliance at high frequencies. One manufacturer even offers a cord with a ground pin that can be unscrewed to prevent gound loops. Nowhere does he claim UL listing and I don't think such a device would get one. Frankly, a small capacitor across the line used to surpress start up thumps on many amplifiers should shunt out rf just fine.

[Guest Sean]

I can tell from your posts that you've never really listened to or compared "low feedback" designs and / or "fancy cabling" to any great extent. While you can tell me that you have, nobody that i know of that has actually done so with an open mind would make the type of statements that you did.

As someone that designs / repairs / modifies electronics for a living, i can tell you that spec's do mean quite a bit, but you should work towards educating your ears and improving your listening skills. When you get good at listening, you'll find that your ears verify the specs, not contradict them. It is at this point that you'll realize that low feedback sounds far more linear due to the lack of "counter-productive" correction circuitry employed. After all, you can't fix a problem once it has already happened, all you can do is minimize the chances of it ever happening to begin with. Build the circuit to perform the best possible and then employ minimal amounts of correction to maintain linearity and increase stability.

As far as cabling goes, most all of it trades one disadvantage for another. Very few cables are scientifically designed and / or take all of the various factors into account. Some will concentrate on reducing series resistance but forget about nominal impedance. Others will make use of fancy geometries to increase bandwidth but forget about skin effect, etc... Given the fact that most electronics are under-designed to begin with and most people lack proper listening skills, it is no wonder that the "myths" of "everything sounds similar that measures similar" has been able to carry on for so long.

As far as Brett's original comments go, the more difference that a power cord makes, the more under-designed the component is. Having said that, YES, power cords can and do make an audible difference with most components. Sean

>

[Guest Sean]

You bring up some valid points but impliment them poorly, possibly due to a lack of understanding or on purpose to try and prove your point to those that don't know better.

Here's a case in point. A ferrite bead on the ground conductor does not make the path to ground "high impedance". What it does do is cause an impedance bump in that specific area that could make it more difficult for specific frequencies to be passed to ground. Given that the AC grounding system is implimented as a "safety catch" for 60 Hz ( and the harmonics generated ) AC and / or a lightning strike, the application of an "RF suppression choke" to a large gauge ground wire is of little consequence in the grander scheme of things.

Having said that, i agree that placing an RF choke on the ground is not a good idea. The best thing that one can do is to make sure that the path to ground is as clean, short and low resistance as is humanly possible. The main reason why people run into problems with their AC and noise is due to poorly designed gear, inadequate AC filtration and a poor, high resistance path to ground. While there are MANY ways to deal with any of those given situations, the easiest and least costly is to maintain the ground system. Sean

>

[Guest Bret]

>As far as Brett's original comments go, the more difference that a power cord makes, the more under-designed the component is.<

That's an interesting statement. The amplifier in question was a Threshold 400A from about 1976, all stock, all original (in fact, this is the nicest example of one of these I've seen). This thing's a museum-piece.

And because of that we have questions about the caps, transformer, outputs, etc. Being a "Class A" amplifier, this puppy runs hot all the time.

We've noticed that it's a little muddy and maybe even shy in the bass regions. I think I'm missing the top of the top when listening to it, but he doesn't seem to agree with me.

There's a guy who will replace all the outputs and the ps caps and. . . something else, for around $350.

BTW - just in case you haven't run into one of the Sunfire amplifiers yet, I got mine, took it to Don's, we hooked it up and listened, then I left it with him. Another time I went back and he had changed speakers.

The first night we were listening to his 10pi's. The Sunfire was much, much more "detailed" than the Threshold but it completely lacks "warmth" (as you can imagine the old Threshold sounds like a piece of mellow tube gear - maybe to an unpleasant extreme at this point in its life).

In recent times I have told Don, repeatedly, that there was something very badly wrong with his AR90s. In fact, it got to the point that I just about didn't want to "go listening" if it meant we were going to be listening to the 90s. With the Sunfire on the 90s they behaved rather better - almost as though they were different speakers.

So since you seem to know a little about things ;-), let me ask: Don dearly loves the warmth and soundstage coming from the Threshold, even in its old age. Do you have a theory about what has aged badly in this amplifier? Should it keep its "warm signature" with new outputs and capacitors on the basis that it is the design, not the components, that make it sound like all warm and lush?

Oh, my final thought on the Sunfire. I wanted to listen to it before I opened it. I'm glad I did. That is one funny-looking amplifier design. If I'd seen the guts first, I would have been so prejudiced against it that I might not like it (which I do).

BTW - I thought it was interesting that Don said, "The Sunfire plays the note, the Threshold performs the note."

Bret

[soundminded]

" A ferrite bead on the ground conductor does not make the path to ground "high impedance". What it does do is cause an impedance bump in that specific area that could make it more difficult for specific frequencies to be passed to ground."

The impedence (2pi*f*L) is dependant on the inductance L which is increased by ferrite beads. The Voltage across the wire is L di/dt + iR. When L is increases, the high frequency components of voltage in an upset condition cause much of the voltage drop to be across the wire, exactly what you don't want. This leaves the live part that has shorted out effectively ungrounded at those voltages.

Power distribution transformers are always grounded, usually to building steel if they are in a steel frame building right at the neutral. We used to run insulated wire for this pupose through metal conduit like EMT to protect it from physical damage. We no longer do that specifically because of the ferrous content of the alloy used. In cases where this situation is discovered in older installations, often some of the insulation is removed at both ends and a bonding jumpers are installed right from the wire to the conduit effectively reducing the effect by using the conduit as the conductor shunting the higer impedence wire inside it out of the circuit.

[Guest Sean]

You basically confirmed what i stated. That is, a ferrite on the ground leg makes the ground frequency selective. At 60 Hz AC, which the mains operate at, the loss of high frequency capacity resultant from the impedance altering inductance isn't a big deal. Proper grounding for safety purposes is still achieved. At frequencies above this, especially RF signals that may be shunted to ground via a power line conditioner ( PLC ), the path becomes resistive and less effective. Sean

>

[Guest Sean]

Here are some general comments pertaining to high bias amps.

1) For optimum sonics, they should be powered up 24/7 i.e. "always on". This increases thermal stability, resulting in more consistent sonics. For best results, the amp should be on for at least 72 hours consecutively to hear what it really sounds like.

2) Many amplifiers are not load stable. This means that they change both tonal and transient characteristics as impedance is varied. Given that most speakers change impedance with frequency, it is possible for an amp to produce specific sonic characteristics with one load ( speaker & speaker cabling ) than what it does with a different load.

As to specific comments, the Threshold 400A is relatively flat in response up to about 2 KHz with most loads. From 2 KHz up to about 12 KHz, the output is elevated. This can result in someone mistaking it as sounding "clearer" or "more detailed" as compared to an amp that is more linear in response. If combined with bright speakers and / or electronics, it can sound quite "bright", "forward" and / or "sibilant".

Above 12 KHz, this amp takes a nose dive in output. Upper harmonics of notes are trunctuated and you loose "airiness". The initial attack of cymbals are quite present ( actually somewhat accentuated ) but the "shimmer" that takes place during decay is shortened / lost. The same thing takes place with such instruments as triangles, etc...

As far as load stability goes, this amp is somewhere in the middle. It does change with loads, but isn't as severe as some other designs. My guess is that changing speaker cables with opposing electrical characteristics with this amp could result in a noticeably different sonic presentation. Since there is no mention of the speakers or cabling being used, i can't comment on what to look for.

As far as the Sunfire amp goes, are you using the voltage or current outputs? Due to the power supply and output stage design, it takes a good 1/2 hour of heavy operation to start doing its' thing. It is VERY sensitive to power line fluctuations and requires a heavy duty circuit with minimal voltage sag. It will not have the resolving power of the Threshold, especially if the Threshold is modified, but it is capable of providing gobs of power without ever getting "nasty" sounding. That is, so long as you can provide the Sunfire with enough AC to do what it wants to do. Even though it is a highly efficient design ( that's why it doesn't run hot ), it can draw GOBS of current on momentary peaks. If you starve it on those peaks, the result is increased smearing and trunctuated dynamics. Sean

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[Guest Bret]

>Since there is no mention of the speakers or cabling being used, i can't comment on what to look for.<

Sure there was. . . you were just in a hurry. We listen with both his AR 10pi's and AR90's.

The cable is a 7.5' run of 12 gauge twisted copper "speaker wire" from Radio Shack and nothing esoteric, but not hardware store lamp cord, either.

Just curious, how did you arrive at the 12k roll-off point? Have you actually tested one of these or are you reading/recalling a test done by someone somewhere?

Bret

[Guest Bret]

>As far as the Sunfire amp goes, are you using the voltage or current outputs?<

Forgot to tell you about the Sunfire. This is a cheap Sunfire, the "Symphonic Reference" and it doesn't have two sets of outputs. I assume, therefore, that the ones it does have are voltage outputs. But since Bob did put "Symphonic" in the name I suppose I shouldn't assume that. "Symphonic" sounds tubish to me. ;-) Anyway, I'm lead to believe that this is a quickly knocked-out design based on making a cheap version of Sunfire's bigger amps. Many expenses seem to have been spared, but it does have balanced inputs, which is odd because the matching preamp has no balanced outputs.

Too bad, because I might have preferred the current outputs on the amp, too.

As far as resolution goes on the Sunfire, it does some things very well. Very well. I'm hearing things in recordings I have never heard before. But by the same token, some things I'm accustomed to hearing very well are strange sounding, almost not there, or almost as though they have been raised an octave.

And even that observation can't be applied evenly. Take the percussion instrument "monkey skulls." I can definitely identify them as monkey skulls (wooden, of course, but skulls as opposed to tuned wood-blocks) more easily with the Sunfire than any other amplifier I've tried. Yet, a triangle in a different recording reaches my ears as a "iiiiing" with very little "ti" (as in "tiiiiiiing") and worse, it sounds very, very "iiiiiiingy" without the accompanying "chaaang" and change in pitch that happens with a real triangle (or on this recording through another setup).

I suspect a different set of harmonics is being accentuated, or maybe attenuated.

The soundstage is very wide and deep with the Sunfire (beginning at the speaker grill and moving back into the wall), but it will not send the image out into the room to greet you (past the grills) like the Threshold will. Nor is it as "tall" as with an SAE MOSFET design.

The bass in the Sunfire is very articulate; so much so that the friend with the Threshold is now having trouble listening to bass with his amplifier after listening to mine.

What we'd both like is a happy medium between the smoothness and middle detail of the Threshold and the control and articulation of the Sunfire. We're relatively sure it exists and that neither of us wants to afford it.

Bret

[soundminded]

Under an upset condition like a short circuit, forget about 60 hz. There can be a lot of energy stored and much of the waveform will analyze as much higher frequencies. This is especially true of any circuit having a SMPS (switching mode power supply) like a computer, printer, even a flourescent lamp with an electronic ballast. Normally zero current flows in the ground circuit. I have no idea what could be achieved by limiting rf noise in a ground circuit. Even with the gain of a radio tuner, it would make a poor antenna.

[Guest Tyreman]

It is doubtful if using brand name equipment that one can here any difference in the use of an esoteric power cord over that of the factory supplied one.

If the home theatre system or stereo sound system is on its own independant breaker within the electrical panel(no fridges,household appliances shutting on and off/sharing its circuit etc.)that is probably a desirable way to go.I have computers as well on separate circuit to.

As we know for home theatre equipment,stereo equipment the speakers are usually the most variable sounding component in the audio chain.

Naturally the rooms basic construction,design,furnishings,flooring,etc./ and the like have a perhaps major or minor influence in the differences along with the differing speaker anomolities of each brand which may or may not be "hearable" dependant on the interaction with the room.

Yes that Stereo Review test was interesting.

We only have several seconds of recall to assess mentally if you will differing equipment soundings.