Why Tube Amps Sound Different (and better) Than SS Amps

[Phelonious Ponk]

You're a patient man, Ralph, thank you.

FWIW, 'voicing an amplifier' seems like a very bad move and I don't know any designers that engage in that practice.

Yes, it seems like a very bad idea. But if not this, what is it that Mr. Lamm is doing?

But to give you some idea of how *we* do it: our amps are fully differential and balanced from input to output. In this way there is an even ordered harmonic cancellation that occurs with every stage, not just the output as in a lot of tube designs. In this way we avoid the most 'euphonic' of tube colorations, the 2nd harmonic. By using linear techniques (triodes, Class A operation, no transformers, single stage of gain) we eliminate the sources of distortion that many amps have to contend with; the result is we don't need negative feedback to obtain low distortion. Odd ordered harmonics do not cancel in push-pull circuits so the best thing is not to generate them in the first place. Because the amplifier has no distinct phase-splitter circuit, we don't have its attendant distortion, meaning that as we decrease the power output, distortion decreases linearly to unmeasurable. In this regard our amps, while push-pull, share the low power/low distortion aspect with SETs. There is no voice or frequency compensation of any kind, yet we get full power bandwidth from 2Hz to 200KHz (-3db at 300KHz).

I will not pretend to fully understand all of this, but what I get makes good sense. It seems to me, however, that the results should be fully measureable and demonstrable. You should be able to show, in terms than any scope-head can understand, that without feedback your amplifiers have distortion that is, if not lower than amps designed with feedback, more than low enough to defy audibility.

The result is that the primary harmonic generation is the 3rd, but at lower levels than seen in an SET. IM distortion is kept very low due to the linearity of the circuit and the independent power supplies (including separate power transformers) for the driver and output sections. IM is also controlled by making sure that the timing constants of the amplifier do not go lower than the timing constants in the power supplies- this prevents modulation of the supplies by the amplifier, which contributes to IMD.

So IM distortion is lower than quality SS amps utilizing feedback? Or as low without negative feedback?

The result is that the amplifier is low in higher ordered harmonic generation, which means that it sounds smooth and its hard to tell how loud its really playing as artificial loudness cues to the human ear/brain system are minimized. So this imparts a relaxed presentation but with obvious speed and detail at the same time.

Exactly how I would characterize the sound of a very well-executed SS active system. Mine should come with a warning lablel: Caution: Music in your ears may be much louder than it appears. Smooth. Effortless. Detailed. Phantom center (and images across the horizontal field) so real I still find myself looking for the speaker.

The weakness of course it that we can't play the amp on just any loudspeaker, but what we found out decades ago is that if the speaker demands that the amp use feedback to sound right on that speaker, the chances are remote that the speaker will sound like real music with any amplifier. IOW we limited our marketplace to only those speakers that have a chance of sounding like real music. Fortunately there are a lot of them out there to choose from.

I can't play my amps on just any loudspeaker either; they're built in. . Thanks again, Ralph. I'm trying to wrap my head around this, but I'm still searching for the differentiator in there. It sounds like you've just taken a very elegant path to low distortion, not lower distortion. And again, if I've misunderstood, if this methodology produces lower distortion, that should be clearly demonstrable to the measurement freaks. Shouldn't it?

Oh, and regarding the use of the rules of human perception, etc, I don't really see that here at all, except for the idea that we find some distortions more aggregious than others. But your methodology seems to focus on all distortions, so I am at a bit of a loss to find the connection.


Tim

 

[Ethan Winer]

papers by CHeever (master's thesis) and Geddes (AES conference papers) have demonstrated again that you can have very low THD and IMD and still get far inferior sound to an amp with 10x or more measured distortion.

I think you're missing something very important here, which is at what level distortion artifacts can't be heard at all. First, the notion that one amplifier having high distortion can "sound better" than another with 1/10th as much measured distortion is extremely unlikely. The three main factors that affect the audibility of distortion are:

1) Due to the masking effect, artifacts at distant frequencies are more audible than artifacts at frequencies near the original. So yeah, a strong 7th harmonic is more audible than a 2nd harmonic at the same level. But normal audio circuits don't work that way! Generally, harmonics fall off in level at higher frequencies, so higher order harmonics farther from the fundamental are almost always much softer than lower order harmonics. A Total THD spec lumps all harmonic artifacts together, and that number is very relevant. Every time I've seen "proof" that THD specs don't matter, the test signals were contrived to favor artifacts at frequencies that don't normally occur in audio gear at those levels.

2) The absolute frequency of artifacts matters at least as much as their overtone number. So content at 2-3 KHz is more audible than content at 200 Hz regardless of the harmonic number.

3) Whenever you have THD you also have IMD. And IMD is always more damaging because the added artifacts are not necessarily related to the source frequencies. Further, IM sum and difference frequencies can be literally anywhere, depending on what frequencies are present at that moment in the music.

So the notion that distortion measurements are irrelevant, and is sometimes claimed, is easy to prove false with a few simple listening tests. All you have to do is add various frequencies to music at various levels, and see at what level you can hear them. The problem is almost nobody does this! So I did it for you. Skip ahead in this video to the Artifact Audibility section that starts around 24:07 (or better, watch the entire video):

AES Audio Myths

Now, you might say "Hey, I know that Halcro has 0.000001% THD so they got rid of nearly all the distortion" but what they have really done is reduced the part that isn't particularly audible and left behind the stuff that is very audible and the ear/brain looks at patterns and if those patterns are not correct it perceives the sound as unnatural.

After you've watched that part of the video, and optionally downloaded the original source Wave files from my web site, you'll understand that 0.000001% THD is never audible by any human under any situation.

--Ethan

 

[Atmasphere]

Yes, it seems like a very bad idea. But if not this, what is it that Mr. Lamm is doing?

You'll have to ask him. He's not been keeping me up to speed

It seems to me, however, that the results should be fully measureable and demonstrable. You should be able to show, in terms than any scope-head can understand, that without feedback your amplifiers have distortion that is, if not lower than amps designed with feedback, more than low enough to defy audibility.

We do pay quite a lot of heed to what our sine wave performance is. The problem here is that you have to do some sophisticated measurements to really get to the bottom of it. As we all know, its not about sine waves in the end. What is important is how the amplifier performs with a waveform that is in constant change and never repeats. That is what real music does.

To solve this we have to look at something called Chaos Theory. It really has a bit more of the tools needed to do the analysis required, IOW what is the distortion with a waveform that is in constant change? FWIW, Chaos Theory predicts that an amplifier with loop negative feedback will be a Chaotic system; interestingly the formula for a classic Chaotic system and that of negative feedback are the same. Prior to the development of the field of Chaos Theory, Norman Crowhurst published the Strange Attractor for an amplifier with feedback. Anyway, Chaos theory suggests that an amplifier with feedback will have a property of bifurcation, which we call 'distortion'. The point here is that with a constantly changing waveform, the distortion will not be completely consistent with regards to how the amp behaves with a sine wave. Right now we don't have that kind of test equipment, although I do think we have the hardware now to make it happen.

So IM distortion is lower than quality SS amps utilizing feedback? Or as low without negative feedback?

Interesting question, huh? Intermodulation is a sign of non-linearity, FWIW. We're getting numbers in the 0.005% range, depending on tube conditions. Without feedback.

Exactly how I would characterize the sound of a very well-executed SS active system. Mine should come with a warning lablel: Caution: Music in your ears may be much louder than it appears. Smooth. Effortless. Detailed. Phantom center (and images across the horizontal field) so real I still find myself looking for the speaker.

I can't play my amps on just any loudspeaker either; they're built in. . Thanks again, Ralph. I'm trying to wrap my head around this, but I'm still searching for the differentiator in there. It sounds like you've just taken a very elegant path to low distortion, not lower distortion. And again, if I've misunderstood, if this methodology produces lower distortion, that should be clearly demonstrable to the measurement freaks. Shouldn't it?

Oh, and regarding the use of the rules of human perception, etc, I don't really see that here at all, except for the idea that we find some distortions more aggregious than others. But your methodology seems to focus on all distortions, so I am at a bit of a loss to find the connection.


Tim

Actually I pointed out several things that relate entirely to human perceptual issues. For example, keeping the odd ordered harmonics down, as they are loudness cues to the ear. To your former comment, the ear translates distortion into tonality. IM, higher ordered harmonics and IM's poorer cousin inharmonic distortion all come off as brightness to the ear. As such they tend to be unpleasant and its why two amps can have the same apparent bandwidth on the bench but one can sound bright and the other does not. IOW, its better if the amp is low distortion and it makes a difference how we make it be low distortion. If we add feedback to do it, we are introducing IM, HD and inharmonic distortions that are audible as brightness. Or we can avoid feedback and use other techniques which is the path I took. And you are right- if you spend the time with the test equipment, you can ferret this stuff out, but it won't tell the whole story because of limitations in our methodology and misconceptions about how an amplifier should drive a speaker (see http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php for more about that). It is the latter that makes the amp look bad on paper, while not seeming to do such a bad job in the real world.

What I am referring to is output impedance, in case I was a little too obtuse. This whole thing about feedback and output impedance I find really humorous. You see, a lot of people will tell you that without feedback, the output impedance of the amp will be higher, but I can easily show that the output impedance of the amp is not affected by feedback. I think I will wait until someone challenges me on that one though. This post is long enough...

 

[Phelonious Ponk]

Thanks again, Ralph. A good read.

Tim

 

[LL21]

Thanks again, Ralph. A good read.

Tim

+1...in fact for me, it's "a good RE-read...and read again...and again."

 

[morricab]

I think you're missing something very important here, which is at what level distortion artifacts can't be heard at all. First, the notion that one amplifier having high distortion can "sound better" than another with 1/10th as much measured distortion is extremely unlikely. The three main factors that affect the audibility of distortion are:

1) Due to the masking effect, artifacts at distant frequencies are more audible than artifacts at frequencies near the original. So yeah, a strong 7th harmonic is more audible than a 2nd harmonic at the same level. But normal audio circuits don't work that way! Generally, harmonics fall off in level at higher frequencies, so higher order harmonics farther from the fundamental are almost always much softer than lower order harmonics. A Total THD spec lumps all harmonic artifacts together, and that number is very relevant. Every time I've seen "proof" that THD specs don't matter, the test signals were contrived to favor artifacts at frequencies that don't normally occur in audio gear at those levels.



2) The absolute frequency of artifacts matters at least as much as their overtone number. So content at 2-3 KHz is more audible than content at 200 Hz regardless of the harmonic number.


3) Whenever you have THD you also have IMD. And IMD is always more damaging because the added artifacts are not necessarily related to the source frequencies. Further, IM sum and difference frequencies can be literally anywhere, depending on what frequencies are present at that moment in the music.


So the notion that distortion measurements are irrelevant, and is sometimes claimed, is easy to prove false with a few simple listening tests. All you have to do is add various frequencies to music at various levels, and see at what level you can hear them. The problem is almost nobody does this! So I did it for you. Skip ahead in this video to the Artifact Audibility section that starts around 24:07 (or better, watch the entire video):


AES Audio Myths



After you've watched that part of the video, and optionally downloaded the original source Wave files from my web site, you'll understand that 0.000001% THD is never audible by any human under any situation.

--Ethan

Point 1
You are simply wrong here and the funny thing is it has been know for more than 50 years that THD and IMD are basically meaningless (starting at least with D.E.L Shorter from the BBC and Norman Crowhurst in the 1950s!). This was most recently discussed in detail by Cheever (2001) and Geddes (2009?), who actually found a slightly NEGATIVE correlation between subjective sound quality and THD+IMD. Human perception seems to be quite complicated and PATTERN related. D.E.L Shorter was the first to propose that the the harmonics should be weighted based on the square of the harmonic order...even this proved to be too optimistic (Cheever and Geddes have come up with much sharper non-linearity in the way we hear these things).

As for amps with falling levels of distortion with harmonics...I can show you plenty of measurement examples where this is not true (many have a picket fence up to the 20th harmonic and beyond). However, according to Cheever the level of drop off required with increasing order is severe...because that is how the ear/brain operates as well.

Point 2
I would agree that it is important but not more important. A big cause of "tubey" sound is the harmonic distortion created by output transformer saturation that "sprays" harmonic distortion right up through the midrange. Interestingly, if you look at the distortion vs. frequency of many SS amps with high feedback you will find that the distortion is INCREASING, sometimes up to factor of 10, once you get above about 1000Hz...so not only is the harmonic content wrong it is also quite a bit higher than mids.

Point 3
And you know this how exactly? According to Geddes they found that IMD was no better at predicting sound quality than THD, both which was negligible. You have been told by engineers or audio reviewers that it is important but some of the best sounding amps out there don't measure particularly well on either THD OR IMD. Again, it is far more complicated than that.

I will watch the video when I get a chance.

 

[mep]

Point 1
You are simply wrong here and the funny thing is it has been know for more than 50 years that THD and IMD are basically meaningless (starting at least with D.E.L Shorter from the BBC and Norman Crowhurst in the 1950s!). This was most recently discussed in detail by Cheever (2001) and Geddes (2009?), who actually found a slightly NEGATIVE correlation between subjective sound quality and THD+IMD. Human perception seems to be quite complicated and PATTERN related. D.E.L Shorter was the first to propose that the the harmonics should be weighted based on the square of the harmonic order...even this proved to be too optimistic (Cheever and Geddes have come up with much sharper non-linearity in the way we hear these things).

As for amps with falling levels of distortion with harmonics...I can show you plenty of measurement examples where this is not true (many have a picket fence up to the 20th harmonic and beyond). However, according to Cheever the level of drop off required with increasing order is severe...because that is how the ear/brain operates as well.

Point 2
I would agree that it is important but not more important. A big cause of "tubey" sound is the harmonic distortion created by output transformer saturation that "sprays" harmonic distortion right up through the midrange. Interestingly, if you look at the distortion vs. frequency of many SS amps with high feedback you will find that the distortion is INCREASING, sometimes up to factor of 10, once you get above about 1000Hz...so not only is the harmonic content wrong it is also quite a bit higher than mids.

Point 3
And you know this how exactly? According to Geddes they found that IMD was no better at predicting sound quality than THD, both which was negligible. You have been told by engineers or audio reviewers that it is important but some of the best sounding amps out there don't measure particularly well on either THD OR IMD. Again, it is far more complicated than that.

I will watch the video when I get a chance.

Wear some hip waders when you watch it in order to keep your shoes and pants clean because it will get deep.

 

[Ethan Winer]

I will watch the video when I get a chance.

I'm sure my video will answer all of your questions. And again, I urge (beg) you to test this for yourself using the methods I show. Then you'll understand why all three of my points above are valid. Indeed, people who haven't done tests like this have no idea what they're talking about. They're merely parroting the opinions of others who never did such tests either!

Do you have a computer and suitable audio software? If not, I'll be glad to walk you through it. There's plenty of freeware available, though the Wave files on my web site linked from the video do a good job showing at what level typical artifacts are audible.

--Ethan

 

[Atmasphere]

After viewing the video I see some problems in the first half (I don't have much argument with the second half).

Example- without understanding the science behind it, without doing any measurements, Ethan poo-pooed the idea that power cables can make a difference. Its not hard to measure what they do- I have seen a power cord rob the amp of nearly 30% of its output power- and yet power cords don't make a difference? Really??

Ethan does not seem to know what some audiophile terms relate to on his page 'Proper Terminology': 'warm', 'cold', 'forward', 'silky' all refer to forms of distortion, not frequency response errors. This seems to stem from his lack of understanding that the ear translates distortion into tonality. Its my guess that this is one reason why Ethan often gets into trouble on the high end audio forums. Now I will concede that most audiophiles don't realize that they are talking about distortion issues with these terms either; but they do seem to realize that they are not frequency response related, and given that they can't see in the specs what is causing the tonality these terms have thus arisen.

His noise demo is really about masking. Its not about whether you can hear distortion or not (see prior paragraph). So I see that particular demo as a failure since it demonstrates the wrong thing.

I found other problems but I am just giving some examples. When he gets into the digital part of the video I really don't have much argument and this thread is not about that stuff anyway.

 

[Phelonious Ponk]

After viewing the video I see some problems in the first half (I don't have much argument with the second half).

Example- without understanding the science behind it, without doing any measurements, Ethan poo-pooed the idea that power cables can make a difference. Its not hard to measure what they do- I have seen a power cord rob the amp of nearly 30% of its output power- and yet power cords don't make a difference? Really??

Ethan does not seem to know what some audiophile terms relate to on his page 'Proper Terminology': 'warm', 'cold', 'forward', 'silky' all refer to forms of distortion, not frequency response errors. This seems to stem from his lack of understanding that the ear translates distortion into tonality. Its my guess that this is one reason why Ethan often gets into trouble on the high end audio forums. Now I will concede that most audiophiles don't realize that they are talking about distortion issues with these terms either; but they do seem to realize that they are not frequency response related, and given that they can't see in the specs what is causing the tonality these terms have thus arisen.

His noise demo is really about masking. Its not about whether you can hear distortion or not (see prior paragraph). So I see that particular demo as a failure since it demonstrates the wrong thing.

I found other problems but I am just giving some examples. When he gets into the digital part of the video I really don't have much argument and this thread is not about that stuff anyway.

I'm not Ethan and I don't play him on TV, but I think most of us who don't believe in esoteric power cords are not saying they can't make a difference. Of course they can. And if they're robbing an amplifier of 30% of it's power, that's a great example. That is a power cord that is broken. One that is not performing it's core job of carrying sufficient electricity from the wall outlet to the component. What we skeptics don't believe is that you can have two power cords which are both carrying sufficient power to the component, one came with the component, the other came with a $2k price tag and the second one is not only powering the component, it is transforming the sound of the system from bland to transcendent. We cable skeptics believe that a properly-functioning power cable (carriying the electricity it should, not adding audible noise between wall and component, will sound the same as the "high end" cord. I've done a fair amount of reading on the subject and have seen nothing in the science to support anything different. Have you?

Tim

 

[JackD201]

That is a power cord that is broken.

Tim

Nope. Not necessarily.

 

[Phelonious Ponk]

Nope. Not necessarily.

We can argue over the semantics if you like, Jack, but to me, a cord that fails to deliver sufficient power to the component it is supposed to be powering is...OK, maybe it's not broken. Maybe the manufacturer just supplied a POS cable. But if they spec'd the cable properly and it is only delivering enough power to the component to run at 70%, it's broken in my book.

Tim

 

[Atmasphere]

I'm not Ethan and I don't play him on TV, but I think most of us who don't believe in esoteric power cords are not saying they can't make a difference. Of course they can. And if they're robbing an amplifier of 30% of it's power, that's a great example. That is a power cord that is broken. One that is not performing it's core job of carrying sufficient electricity from the wall outlet to the component. What we skeptics don't believe is that you can have two power cords which are both carrying sufficient power to the component, one came with the component, the other came with a $2k price tag and the second one is not only powering the component, it is transforming the sound of the system from bland to transcendent. We cable skeptics believe that a properly-functioning power cable (carriying the electricity it should, not adding audible noise between wall and component, will sound the same as the "high end" cord. I've done a fair amount of reading on the subject and have seen nothing in the science to support anything different. Have you?

Tim

Yes.

But first- the cord in question had a 2 volt drop across its length. That's enough to mess with any amplifier that has significant power draw. There was nothing at all wrong with the cord, other than it cost $12.00- lots of inexpensive power cords rated at 10amps will do the same thing.

But there is more to it than that. The other problem has to do with high frequency response of the cable, here's why: In the power supply of a typical amplifier you have a transformer, rectifier and a set of filter caps. As the amp plays it discharges the caps, which are replenished whenever the voltage from the transformer is higher than that of the caps. Most of the time the depletion from one peak of the AC power to next is not all that much, so what happens is the rectifiers turn on (commutate) only at the peak of the waveform, possibly for only a few milliseconds.

However a fair amount of current may have to flow at that time. If the cord is not up to it, current limiting can occur, even if the power cord is otherwise OK at lower frequencies, say at 60Hz. You have to understand that the brief pulse at the peak of the waveform represents a very high frequency. In a tube amplifier in particular, which has a filament draw, you have the cord having to do both high and low frequencies at the same time. Now it happens that ROMEX is pretty good at this, and if you were to build a cable out of ROMEX it would work just fine. However ROMEX is illegal as a power cable, which has to be flexible.

The difference between the best and the worst as far as HF stuff goes is not all that much, maybe about 7% (which is what I have been able to measure). That's what audiophiles argue over.

Do you have to have a really expensive cable to fix this? I don't think so, what you need is a cable that works and that has little to do with price. One caveat: the connectors play a role. If you find that after several hours of operation the connectors are getting warm, you have a problem. So they need to be good quality with good connections to the cable. Some molded cables are OK in this regard and others are not. Some people claim that shielded cables work better but I can't comment on that as I've not measured anything in that regard one way or the other- I suspect that such might be true if your gear has some sort of design flaw rendering it susceptible to interference.

So the take away- first, tube amps (the subject of this thread) are more susceptible to power cords on account of their filament circuits (its not just the B+ that goes down, if the filament aren't lit right the transconductance of the tubes goes down and you sure as heck can measure that!). But any amp that is high power will be affected as well. Funny thing, I have several customers that claim to hear the effects on the power supplies of ESLs as well. I've not been able to test anything like that yet so I can't comment, but its interesting.

2nd, you want good connectors and that act alone is going to put the cable over $100 retail. Hubble connectors aren't cheap, and you have to pay someone to put them on a bit of wire.

A DVM is all the is needed to see if a cord might make a difference. We have a DVM with 5 1/2 digits but I have been able to see the voltage drop on a regular 3 1/2 digit DVM.

 

[Phelonious Ponk]

Yes.

But first- the cord in question had a 2 volt drop across its length. That's enough to mess with any amplifier that has significant power draw. There was nothing at all wrong with the cord, other than it cost $12.00- lots of inexpensive power cords rated at 10amps will do the same thing.

But there is more to it than that. The other problem has to do with high frequency response of the cable, here's why: In the power supply of a typical amplifier you have a transformer, rectifier and a set of filter caps. As the amp plays it discharges the caps, which are replenished whenever the voltage from the transformer is higher than that of the caps. Most of the time the depletion from one peak of the AC power to next is not all that much, so what happens is the rectifiers turn on (commutate) only at the peak of the waveform, possibly for only a few milliseconds.

However a fair amount of current may have to flow at that time. If the cord is not up to it, current limiting can occur, even if the power cord is otherwise OK at lower frequencies, say at 60Hz. You have to understand that the brief pulse at the peak of the waveform represents a very high frequency. In a tube amplifier in particular, which has a filament draw, you have the cord having to do both high and low frequencies at the same time. Now it happens that ROMEX is pretty good at this, and if you were to build a cable out of ROMEX it would work just fine. However ROMEX is illegal as a power cable, which has to be flexible.

The difference between the best and the worst as far as HF stuff goes is not all that much, maybe about 7% (which is what I have been able to measure). That's what audiophiles argue over.

Do you have to have a really expensive cable to fix this? I don't think so, what you need is a cable that works and that has little to do with price. One caveat: the connectors play a role. If you find that after several hours of operation the connectors are getting warm, you have a problem. So they need to be good quality with good connections to the cable. Some molded cables are OK in this regard and others are not. Some people claim that shielded cables work better but I can't comment on that as I've not measured anything in that regard one way or the other- I suspect that such might be true if your gear has some sort of design flaw rendering it susceptible to interference.

So the take away- first, tube amps (the subject of this thread) are more susceptible to power cords on account of their filament circuits (its not just the B+ that goes down, if the filament aren't lit right the transconductance of the tubes goes down and you sure as heck can measure that!). But any amp that is high power will be affected as well. Funny thing, I have several customers that claim to hear the effects on the power supplies of ESLs as well. I've not been able to test anything like that yet so I can't comment, but its interesting.

2nd, you want good connectors and that act alone is going to put the cable over $100 retail. Hubble connectors aren't cheap, and you have to pay someone to put them on a bit of wire.

A DVM is all the is needed to see if a cord might make a difference. We have a DVM with 5 1/2 digits but I have been able to see the voltage drop on a regular 3 1/2 digit DVM.

I think we're having a semantic discussion here, Ralph. You say there is nothing whatsoever wrong with the power cord other than that it only cost $12 and is not up to the task of supplying power to the component. I say that's "something wrong." Very wrong. I'm also assuming, because this discussion was inspired by high-end replacement cords, that the one being replaced is the one that came with the component, not a $12 cord from Wal Mart. Do high-end manufacturers ship their expensive amplifiers with power cords that will not allow their products to perform properly? There's something wrong there, too. It's not just the cord that's "broken" it's the manufacturer. I assume you do not expect your customers to upgrade their power cords to get your amplifiers to perform properly. I expect that of every manufacturer of quality products. I would think that the purchase of after market power cords would be a bit of an insult to any self-respecting manufacturer.

Tim

 

[JackD201]

You know I love ya Tim hence the manner in which my reply was playfully worded. Spec'd is a tricky thing for amps. You'd think 15A or 20A would be good but in reality there are a lot of amps out there that can draw a heck of a lot more on peaks. My own amps aren't exactly considered current guzzlers being sliding A/AB but max draw is rated at 40A. Have I ever hit this? I don't know. What I do know is that I have had cords that I could attribute directly to my amps sagging.

 

[Mark (Basspig) Weiss]

If the 6 feet of power cord concerns people so much, then why aren't they concerned with the dozens of feet of wiring inside the walls and the thousands of feet of aluminum wiring that carries power from the utility?
When my sound system is turned way up (much higher than I would normally listen), the voltage at my 200 amp service panel drops to 96 volts. I've got 4awg 220 volt service going from my panel to the 50 amp dryer-type outlet that feeds my amp racks. I'm sure there's some drop there too, but most of the drop is coming from the service drop from the pole pig to the house. That's a few hundred feet run.
Spending 2 grand to fix the last 6' of an already deficient run is ludicrous--only people with more money than basic electricity skills would buy such things. That money can go toward acoustic improvements, which, in my experience, are only second to speakers, in being the most effective improvement in sound quality you can invest in.

 

[JackD201]

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.

 

[Phelonious Ponk]

You know I love ya Tim hence the manner in which my reply was playfully worded. Spec'd is a tricky thing for amps. You'd think 15A or 20A would be good but in reality there are a lot of amps out there that can draw a heck of a lot more on peaks. My own amps aren't exactly considered current guzzlers being sliding A/AB but max draw is rated at 40A. Have I ever hit this? I don't know. What I do know is that I have had cords that I could attribute directly to my amps sagging.

Sorry to hear your amps are sagging, Jack, but that doesn't change the point. If the cords that came with your amps are contributing to the sagging, shame on the manufacturer. They shouldn't get any more of your business. We're not talking about midfi, here...you know, stuff designed to a pretty limited price point and expected to perform up to spec under "normal" conditions. We're talking about the (very) high-end, the supposed pinnacle of audio engineering. At those price points, if they don't over-spec something as simple as a power cord to be absolutely sure it will perform as expected, if there is any reason whatsoever to upgrade something as fundamental as a power cord, any reason to expect that upgrade to make the component perform better, they have failed. Not the most expensive caps on the planet? Designing to a (high-end) price point. A piece of wire that will not deliver the power required to run the component properly? Unspeakably weak. Deserving of contempt. Thank God this isn't happening, with the possible exception of a few wingnut skunkworks boutique operations. Thank God most respectable manufacturers will tell you, correctly, that they sent you a perfectly good power cord with your amp.

Tim

 

[mep]

If the 6 feet of power cord concerns people so much, then why aren't they concerned with the dozens of feet of wiring inside the walls and the thousands of feet of aluminum wiring that carries power from the utility?
When my sound system is turned way up (much higher than I would normally listen), the voltage at my 200 amp service panel drops to 96 volts. I've got 4awg 220 volt service going from my panel to the 50 amp dryer-type outlet that feeds my amp racks. I'm sure there's some drop there too, but most of the drop is coming from the service drop from the pole pig to the house. That's a few hundred feet run.
Spending 2 grand to fix the last 6' of an already deficient run is ludicrous--only people with more money than basic electricity skills would buy such things. That money can go toward acoustic improvements, which, in my experience, are only second to speakers, in being the most effective improvement in sound quality you can invest in.

Man oh man, how high is that??

 

[Atmasphere]

I think we're having a semantic discussion here, Ralph. You say there is nothing whatsoever wrong with the power cord other than that it only cost $12 and is not up to the task of supplying power to the component. I say that's "something wrong." Very wrong. I'm also assuming, because this discussion was inspired by high-end replacement cords, that the one being replaced is the one that came with the component, not a $12 cord from Wal Mart. Do high-end manufacturers ship their expensive amplifiers with power cords that will not allow their products to perform properly? There's something wrong there, too. It's not just the cord that's "broken" it's the manufacturer. I assume you do not expect your customers to upgrade their power cords to get your amplifiers to perform properly. I expect that of every manufacturer of quality products. I would think that the purchase of after market power cords would be a bit of an insult to any self-respecting manufacturer.

Tim

We provide a decent cable for our amps but its a simple fact that audiophiles are going to want to try other cables, and it is routine for the stock cable to be discarded. That is why we put IEC connections on all our stuff, so that the product won't get opened up and tampered with when there is an attempt to replace the cable. Since it is so common for the cable to be discarded, the question then becomes how much do you pay for a throw-away item?? Its a bit of a self-fulfilling prophecy if you go too far down that path. We avoid the lightwieght cables and focus on the heavier ones, also keeping the length to 6 feet... and we play our amps in the shop with the very same cables so we know how they sound.

If the 6 feet of power cord concerns people so much, then why aren't they concerned with the dozens of feet of wiring inside the walls and the thousands of feet of aluminum wiring that carries power from the utility?
When my sound system is turned way up (much higher than I would normally listen), the voltage at my 200 amp service panel drops to 96 volts. I've got 4awg 220 volt service going from my panel to the 50 amp dryer-type outlet that feeds my amp racks. I'm sure there's some drop there too, but most of the drop is coming from the service drop from the pole pig to the house. That's a few hundred feet run.
Spending 2 grand to fix the last 6' of an already deficient run is ludicrous--only people with more money than basic electricity skills would buy such things. That money can go toward acoustic improvements, which, in my experience, are only second to speakers, in being the most effective improvement in sound quality you can invest in.

I addressed this in my prior post. To reiterate: ROMEX works quite well, and if you made a power cord out of it, it would work fine. But such is illegal, as ROMEX is a solid core wire. One thing worth pointing out- the less you pay for the cable, the more you have to audition them because there is a lot of variability with cheap cables. Usually an expensive cable will have good connectors and connections, will be built with heavy wire with the proper bandwidth and such, eliminating the need to audition them to make sure they work. For the most part