DIY cables and close minded views

[KeithL]

The resistance of 18 gauge copper wire is 6.51 Ohms per 1000 feet.

This means that a five foot power cord has a resistance of 0.065 Ohms (five feet in each direction = 10 feet).

So, if the amplifier is drawing 120 watts at 120 VAC, that five foot 18 gauge power cord would reduce the 120 V line voltage to 119.935 VAC.

And, if the amplifier is drawing 1200 watts at 120 VAC, that five foot 18 gauge power cord would reduce the line voltage from 120 VAC to 119.35 VAC).

And I would not expect that to have a significant impact on the amplifier (it is far less than the normal variation we see in line voltage in most areas).

(Obviously, if it was a ten foot power cord, the impact would be doubled.)

The reality is that things like how well that 18 gauge wire is crimped into the connectors at the ends will make FAR more difference than the gauge of the copper.

(The copper wire in a 14 gauge or 16 gauge cord is heavier, and so less likely to be damaged by being bent too much, or stepped on... which probably makes more difference than its slightly lower resistance.)

There are also other differences between power cables.

Some cables are shielded - which may help them avoid picking up noise from other components or radiating noise that may in turn be picked up by other gear.

And some cables are crimped to the connectors much more securely and tightly than others...

And some really poor quality cables may be subject to contact corrosion...

My guess would be that his amplifier sounds better than yours because either:

1) his room or his speakers are different

2) his amplifier really is different (perhaps it is a different design revision than yours)

3) it's expectation bias and somebody is imaging it (have you actually heard them side by side?)

There is no possible theoretical reason why a heavier gauge power cord would dull treble.

(If anything, and if it was replacing a cable that really had too much resistance, then the heavier cord would give you more solid bass.)

(Even goofy power cables with extra circuitry in them, even if it causes actual problems, would be unlikely to "dull the treble".)

I suppose I should throw in the idea that, if we're talking about a TUBE amplifier, and the power supply isn't especially stable...

The power supply could have some odd reaction to the electrical characteristics of certain really odd power cables.

(It's really unlikely - but at least possible.)

Jul 20, 2021 16:26:23 GMT -5 boomzilla said:

Since this thread is already wet and wild, allow me to toss a hand grenade into the punchbowl...

I've a friend who has a VERY powerful amplifier (250WPC @ 8 Ohms, if I remember right). I've heard this amp off and on for over a year at his place and thought it one of the best sounding amps I'd heard (in addition to being able to power ANY speaker to louder than I want to listen). So long story short, I bought one. And (of course) mine doesn't sound as good as his. So I started asking questions.

His has been slightly modified. The original ¼" phone jacks have been replaced with RCA jacks, and the original captive power cord has been replaced with a standard IEC power input jack. I could understand the audio jack replacement, but asked about the IEC power one. He said he wanted to try out fancy power cords to see if they improved the sound.

His conclusion (after trying over 20 different power cables): A no-name 18 AWG power cord (originally built for computer equipment) sounded best!

WTF? This goes against the expressed philosophy of every fancy power cable maker on the planet. Have I confirmed the experiment with my amp? Nope - I haven't taken time yet. But you can bet that I'll at least try it. It may be possible that at the amplifier's "normal" current draw ( with one watt or less of audio output ) that an 18AWG power cord is not only sufficient, but even more than sufficient. If audio amigo was trying to squeeze every one of those 250WPC out of his amp, I'd suspect that the limitations of the 18AWG power cord would become audibly manifest, and very quickly.

So what did audio amigo have against the larger power cables? He said that they dulled the treble of his amplifier. Never having heard his amp with more robust power cords, I can't verify or dispute this claim. But I can say that either because of OR in spite of his 18AWG power cord, his amplifier sounds amazing!

Now since everybody has closets full of 18AWG computer power cords, this should be a very easy experiment to reproduce. Anyone willing to try it?

Boomzilla

[brutiarti]

Dis anybody try the Schroeder method??
Doug Schroeder Method

[DYohn]

Jul 20, 2021 13:24:27 GMT -5 AudioHTIT said:

Jul 20, 2021 11:28:20 GMT -5 405x5 said:

“Forum etiquette” is not licensing to make false claims.

Ok, getting back to specifics, what in the OP of the thread in question is a “false claim”, and what is your expertise in claiming empirically that it is? If it’s just an opinion, do you think that you should post it in someone’s Emporium / For Sale thread?

The thread in question:
emotivalounge.proboards.com/post/1074505/thread

If you look at the post from me quoted by the OP from the other thread to start this one (before someone removed several posts from the original thread) I specifically compliment the OP for NOT making any spurious claims since he said he used the 8AWG wire simply because he could. "Go big or go home" is what he posted. I said cool, a nice honest (and legitimate) answer. It was only in THIS thread where he came after me for daring to ask a question that he began making claims not backed by science.

[AudioHTIT]

Jul 20, 2021 19:02:33 GMT -5 DYohn said:

Jul 20, 2021 13:24:27 GMT -5 AudioHTIT said:

Ok, getting back to specifics, what in the OP of the thread in question is a “false claim”, and what is your expertise in claiming empirically that it is? If it’s just an opinion, do you think that you should post it in someone’s Emporium / For Sale thread?

The thread in question:
emotivalounge.proboards.com/post/1074505/thread

If you look at the post from me quoted by the OP from the other thread to start this one (before someone removed several posts from the original thread) I specifically compliment the OP for NOT making any spurious claims since he said he used the 8AWG wire simply because he could. "Go big or go home" is what he posted. I said cool, a nice honest (and legitimate) answer. It was only in THIS thread where he came after me for daring to ask a question that he began making claims not backed by science.

I think we should all make our points without calling anybody out, and that (with the exceptions I mentioned before) we should leave people’s Emporium posts alone (and be more cognizant of the OP whenever we post). But those are just my opinions and I’ll have to let my points stand on their own.

[DYohn]

Jul 20, 2021 19:53:22 GMT -5 AudioHTIT said:

Jul 20, 2021 19:02:33 GMT -5 DYohn said:

If you look at the post from me quoted by the OP from the other thread to start this one (before someone removed several posts from the original thread) I specifically compliment the OP for NOT making any spurious claims since he said he used the 8AWG wire simply because he could. "Go big or go home" is what he posted. I said cool, a nice honest (and legitimate) answer. It was only in THIS thread where he came after me for daring to ask a question that he began making claims not backed by science.

I think we should all make our points without calling anybody out, and that (with the exceptions I mentioned before) we should leave people’s Emporium posts alone (and be more cognizant of the OP whenever we post). But those are just my opinions and I’ll have to let my points stand on their own.

Sure. And the point I keep trying to make is I DID leave his emporium post alone. It was only after he marked the item as SOLD that I asked him why he decided to use such overkill wire for his DIY power cord. He at first seemed cool with it, then his panties apparently became bunched over it, which is not my farking problem.

[LCSeminole]

OK, here goes nothing!!!

First of all, full disclosure, I deleted all of the posts in the OP's "For Sale" thread that weren't directly related to his actual sale. Secondly, I too am one of those that can't stand crapping on anyone's "For Sale" post.
Third, I read each and everyone of the posts in that "For Sale" thread, and can confirm Dyohn's posts were after the OP had posted the item was "SOLD", and I don't consider Dyohn's questions/comments after the "SOLD" as thread crapping.
Fourth, I too was thinking what Dyohn was thinking about the NEC and ANSI specifications(thats the mathematician and physics part of me thinking).
Fifth, there were other extraneous posts in the OP's thread that triggered me to delete all off sale talk, and at least one or two of these could have easily been construed as unnecessary, so I completely see why the OP got a bit irritated.

Thank you to all of you for being adults and talking it out like adults.

[LuisV]

[405x5]

IEC Six feet 16 gauge….($6.99)

[boomzilla]

And I DID try the 18AWG power cord thing. I'm currently running my Emotiva PA-1 mono block amps with about a 1-meter long pair of IEC power cords. And?

The first evening, when the amps were cold, I actually thought that things sounded slightly WORSE than with the 12AWG power cables. Did I swap back and forth? No because I did want the amps to warm up. So I left the amps on 24 hours and came back the next evening.

Now the amps have more body and depth than I've heard from them before. they sounded so good that my significant other came in to listen (a rare occurrence). Would the amps have improved as much regardless of the power cords? It's possible. It's been my habit in the past to turn the amps off after every listening session, and start them up again at the beginning of the next. I think that this is the first time that I've left them on for 24 hours straight.

But for whatever reason, the amps are definitely sounding their best (or at least, the best I've heard them sound). It's unfair to claim that the 18AWG power cords are the cause of the improvement. But it's also absolutely fair to say that the 18AWG power cords don't seem to be hurting the low-volume performance of these class-D amplifiers.

This is perhaps curious in that Class A & AB amps typically have more capacitive storage in their power supplies, and should therefore maybe be less demanding of the power supply voltage stability. Whereas Class D designs, if I remember correctly, typically use switching power supplies that rely on "just in time" current replacement from the wall circuit. I may have this wrong, so take it with a grain of salt. But if I'm correct, then Class D amplifiers should be more reliant on a stiff wall supply than other types.

Of course, as KeithL has pointed out, even 18AWG power cords aren't insufficient for audio amplifier use, so the above paragraph may be irrlelvent even if it is accurate (the latter very much in question).

But in any case, I'm really enjoying the fine sound from my PA-1 amps!

[KeithL]

Interesting results there.

The one thing you're wrong about - sort of - is about how sensitive switching supplies are to line regulation.

With a NON-REGULATED power supply the supply voltage will actually vary directly with the line voltage.

So, typically, if the line voltage drops 2%, then the voltage rails supplying the output stage will be reduced by a similar amount.

This applies to the rail voltage that powers the output stages of pretty much all amplifiers with linear power supplies.

And, in most cases, this will reduce the maximum output power available by a similar small percentage (it should NOT otherwise affect the gain or "dynamics").

The purpose of using large filter capacitors is to provide plenty of "power reservoir" so the output voltage doesn't sag too badly under load.

(With this type of power supply, as the load increases, the voltage drops, and the noise increases, and larger storage capacitors help prevent both of these from occurring.)

With a LINEAR REGULATED power supply the output voltage of the power supply is FIXED.

So, for example, if you have a "50V regulated power supply" somewhere between 55V and 70V goes in...

And the output remains at 50V as long as the input voltage remains within that range.

The only time the input voltage will affect the output voltage is if it sags low enough that it gets too close to the output voltage.

Regulated power supplies all have a "minimum drop" - which specifies how closely their input voltage can approach the output voltage before they "go out of regulation".

(And, as long as that "drop" is maintained, any change in voltage, or noise that may be present in the power reservoir, is "buzz sawed off the top".)

Of course big power amplifiers don't use linear regulated power supplies for their output stages because they tend to be big, heavy, expensive, and inefficient.

With a typical SWITCHING SUPPLY the output voltage is also fixed.

However, in contrast to a typical linear regulated supply, the initial "pool" of unregulated power that "feeds" the regulated section is run at a MUCH higher voltage (around 300V).

This means that, even if the line voltage drops by a significant percentage, or the primary power pool is depleted by a significant percentage, THE OUTPUT VOLTAGE IS NOT AFFECTED.

(There is a huge amount of "clearance" between the voltage going into the regulator and the voltage coming out.)

So, yes, if the wall current were to just plain stop, a switching supply would lose power relatively quickly...

But, short of that, it is completely immune to almost any sort of normal variation, and that includes variation due to heavy draw from the load depleting the supply pool itself...

(Under normal operation the voltage in our power reservoir would have to drop tens or hundreds of volts before it would affect the output voltage.)

This applies both to the big SMPS we use in our XPA Gen3 amps...

And to the SMPS that powers the Class D output stage in the PA-1...

Jul 27, 2021 3:35:32 GMT -5 boomzilla said:

And I DID try the 18AWG power cord thing. I'm currently running my Emotiva PA-1 mono block amps with about a 1-meter long pair of IEC power cords. And?

The first evening, when the amps were cold, I actually thought that things sounded slightly WORSE than with the 12AWG power cables. Did I swap back and forth? No because I did want the amps to warm up. So I left the amps on 24 hours and came back the next evening.

Now the amps have more body and depth than I've heard from them before. they sounded so good that my significant other came in to listen (a rare occurrence). Would the amps have improved as much regardless of the power cords? It's possible. It's been my habit in the past to turn the amps off after every listening session, and start them up again at the beginning of the next. I think that this is the first time that I've left them on for 24 hours straight.

But for whatever reason, the amps are definitely sounding their best (or at least, the best I've heard them sound). It's unfair to claim that the 18AWG power cords are the cause of the improvement. But it's also absolutely fair to say that the 18AWG power cords don't seem to be hurting the low-volume performance of these class-D amplifiers.

This is perhaps curious in that Class A & AB amps typically have more capacitive storage in their power supplies, and should therefore maybe be less demanding of the power supply voltage stability. Whereas Class D designs, if I remember correctly, typically use switching power supplies that rely on "just in time" current replacement from the wall circuit. I may have this wrong, so take it with a grain of salt. But if I'm correct, then Class D amplifiers should be more reliant on a stiff wall supply than other types.

Of course, as KeithL has pointed out, even 18AWG power cords aren't insufficient for audio amplifier use, so the above paragraph may be irrlelvent even if it is accurate (the latter very much in question).

But in any case, I'm really enjoying the fine sound from my PA-1 amps!

[boomzilla]

Thanks KeithL - So if I understand you correctly (a big “if’” I’ll admit) a switching power supply should be more immune to power cord variations than other types. I’m not referring to power company variations, but rather the effects (if any) of the wire between the wall socket and the amplifier. Correct?

[KeithL]

That is correct.

As long as the power cable is able to supply the overall amount of current required there is no possible excuse for it to have any more subtle effect on "sound quality" with a SMPS.

(And, if the cable were unable to supply sufficient current, the power supply would "drop out of regulation", and the effect of that happening would be very obvious.)

Jul 27, 2021 9:50:23 GMT -5 boomzilla said:

Thanks KeithL - So if I understand you correctly (a big “if’” I’ll admit) a switching power supply should be more immune to power cord variations than other types. I’m not referring to power company variations, but rather the effects (if any) of the wire between the wall socket and the amplifier. Correct?

[Ex_Vintage]

Jul 20, 2021 17:31:01 GMT -5 KeithL said:

The resistance of 18 gauge copper wire is 6.51 Ohms per 1000 feet.

This means that a five foot power cord has a resistance of 0.065 Ohms (five feet in each direction = 10 feet).

So, if the amplifier is drawing 120 watts at 120 VAC, that five foot 18 gauge power cord would reduce the 120 V line voltage to 119.935 VAC.

And, if the amplifier is drawing 1200 watts at 120 VAC, that five foot 18 gauge power cord would reduce the line voltage from 120 VAC to 119.35 VAC).

And I would not expect that to have a significant impact on the amplifier (it is far less than the normal variation we see in line voltage in most areas).

(Obviously, if it was a ten foot power cord, the impact would be doubled.)

The reality is that things like how well that 18 gauge wire is crimped into the connectors at the ends will make FAR more difference than the gauge of the copper.

(The copper wire in a 14 gauge or 16 gauge cord is heavier, and so less likely to be damaged by being bent too much, or stepped on... which probably makes more difference than its slightly lower resistance.)

There are also other differences between power cables.

Some cables are shielded - which may help them avoid picking up noise from other components or radiating noise that may in turn be picked up by other gear.

And some cables are crimped to the connectors much more securely and tightly than others...

And some really poor quality cables may be subject to contact corrosion...

My guess would be that his amplifier sounds better than yours because either:

1) his room or his speakers are different

2) his amplifier really is different (perhaps it is a different design revision than yours)

3) it's expectation bias and somebody is imaging it (have you actually heard them side by side?)

There is no possible theoretical reason why a heavier gauge power cord would dull treble.

(If anything, and if it was replacing a cable that really had too much resistance, then the heavier cord would give you more solid bass.)

(Even goofy power cables with extra circuitry in them, even if it causes actual problems, would be unlikely to "dull the treble".)

I suppose I should throw in the idea that, if we're talking about a TUBE amplifier, and the power supply isn't especially stable...

The power supply could have some odd reaction to the electrical characteristics of certain really odd power cables.

(It's really unlikely - but at least possible.)

Jul 20, 2021 16:26:23 GMT -5 boomzilla said:

Since this thread is already wet and wild, allow me to toss a hand grenade into the punchbowl...

I've a friend who has a VERY powerful amplifier (250WPC @ 8 Ohms, if I remember right). I've heard this amp off and on for over a year at his place and thought it one of the best sounding amps I'd heard (in addition to being able to power ANY speaker to louder than I want to listen). So long story short, I bought one. And (of course) mine doesn't sound as good as his. So I started asking questions.

His has been slightly modified. The original ¼" phone jacks have been replaced with RCA jacks, and the original captive power cord has been replaced with a standard IEC power input jack. I could understand the audio jack replacement, but asked about the IEC power one. He said he wanted to try out fancy power cords to see if they improved the sound.

His conclusion (after trying over 20 different power cables): A no-name 18 AWG power cord (originally built for computer equipment) sounded best!

WTF? This goes against the expressed philosophy of every fancy power cable maker on the planet. Have I confirmed the experiment with my amp? Nope - I haven't taken time yet. But you can bet that I'll at least try it. It may be possible that at the amplifier's "normal" current draw ( with one watt or less of audio output ) that an 18AWG power cord is not only sufficient, but even more than sufficient. If audio amigo was trying to squeeze every one of those 250WPC out of his amp, I'd suspect that the limitations of the 18AWG power cord would become audibly manifest, and very quickly.

So what did audio amigo have against the larger power cables? He said that they dulled the treble of his amplifier. Never having heard his amp with more robust power cords, I can't verify or dispute this claim. But I can say that either because of OR in spite of his 18AWG power cord, his amplifier sounds amazing!

Now since everybody has closets full of 18AWG computer power cords, this should be a very easy experiment to reproduce. Anyone willing to try it?

Boomzilla

Keiths analysis is generally true except for 2 factoids. Torroidal transformer unregulated power supplies create harmonics in the line current that are much higher in current magnitude than a simple calculation of watts would suggest. In a positive vote for the Gen-3 amps, SMPS supplies do not have this lower order harmonic issues.

[405x5]

Jul 27, 2021 15:46:31 GMT -5 Ex_Vintage said:

Jul 20, 2021 17:31:01 GMT -5 KeithL said:

The resistance of 18 gauge copper wire is 6.51 Ohms per 1000 feet.

This means that a five foot power cord has a resistance of 0.065 Ohms (five feet in each direction = 10 feet).

So, if the amplifier is drawing 120 watts at 120 VAC, that five foot 18 gauge power cord would reduce the 120 V line voltage to 119.935 VAC.

And, if the amplifier is drawing 1200 watts at 120 VAC, that five foot 18 gauge power cord would reduce the line voltage from 120 VAC to 119.35 VAC).

And I would not expect that to have a significant impact on the amplifier (it is far less than the normal variation we see in line voltage in most areas).

(Obviously, if it was a ten foot power cord, the impact would be doubled.)

The reality is that things like how well that 18 gauge wire is crimped into the connectors at the ends will make FAR more difference than the gauge of the copper.

(The copper wire in a 14 gauge or 16 gauge cord is heavier, and so less likely to be damaged by being bent too much, or stepped on... which probably makes more difference than its slightly lower resistance.)

There are also other differences between power cables.

Some cables are shielded - which may help them avoid picking up noise from other components or radiating noise that may in turn be picked up by other gear.

And some cables are crimped to the connectors much more securely and tightly than others...

And some really poor quality cables may be subject to contact corrosion...

My guess would be that his amplifier sounds better than yours because either:

1) his room or his speakers are different

2) his amplifier really is different (perhaps it is a different design revision than yours)

3) it's expectation bias and somebody is imaging it (have you actually heard them side by side?)

There is no possible theoretical reason why a heavier gauge power cord would dull treble.

(If anything, and if it was replacing a cable that really had too much resistance, then the heavier cord would give you more solid bass.)

(Even goofy power cables with extra circuitry in them, even if it causes actual problems, would be unlikely to "dull the treble".)

I suppose I should throw in the idea that, if we're talking about a TUBE amplifier, and the power supply isn't especially stable...

The power supply could have some odd reaction to the electrical characteristics of certain really odd power cables.

(It's really unlikely - but at least possible.)

Keiths analysis is generally true except for 2 factoids. Torroidal transformer unregulated power supplies create harmonics in the line current that are much higher in current magnitude than a simple calculation of watts would suggest. In a positive vote for the Gen-3 amps, SMPS supplies do not have this lower order harmonic issues.

How many factoids are in a Torroidal?

[Ex_Vintage]

I believe the correct number is 3.

[DavidR]

Jul 27, 2021 22:35:20 GMT -5 Ex_Vintage said:

I believe the correct number is 3.

3 is the number of the counting - Book of Armaments

[405x5]

I’ve always been morbidly fascinated by fatal rabbit attack statistics

[creimes]

I've got hospital grade plugs in my system so there!!!!