It´s not US who should prove his wild statements, but HIM.
"The burden of the proof lies on those posting statements against established knowledge"
Fat chance 😉
You pre-assume a rational reason?
Where do you get that from ?
Please read the full FIVE HUNDRED post thread, which is constantly kicked off the road by ... you know who.
Troubleshooting implies testing and measuring.
Not in Rick Miller´s sound system, I might add.
Let us stick to Rick Milletr´s power cable and his unproven statements.
Sit comfortably and wait.
More than likely, yes... Short of a serious manufacturing defect, a grounded power cord is a grounded power cord. I would not think it is in the equipment - any defect in the equipment would be there across all properly functioning cords.
Hal
Hey, you gave me a GREAT idea: I´ll play chess with a pigeon and become MILLIONAIRE on Tik Tok. 🙂 🙂 🙂
"Arguing with idiots is like playing chess with a pigeon. No matter how good you are, the bird will sh!t on the board and strut around like it won anyway."
Hmmm... I see there's a risk in casual reading here rather than engaging in cover-to-cover research. I don't know the history obviously (though I am familiar -- only -- with Rick from his contribution to the noted PSU).
I made my suggestion based on tom's speculation that Rick might have an issue with his system. Rick's claim, then, becomes a symptom. That seemed a reasonable hypothesis to me (as opposed to sarcasm). Hypotheses are meant to be tested. Tom's hypothesis. The test would be to see if the power cord mattered once the incompetence was identified and rectified.
Of course an investigation is predicated on Rick's cooperation. If he doesn't... meh. It's his problem, not ours. But it's important to make the offer, no?
On the other hand, if it's a matter of sarcasm...
And I'm truly interested in an evaluation of the Galo PSU. I'm considering a version of it with transformer secondary snubbers (maybe instead of the diode caps) and the bridge connected signal ground from the Pearl II. Or should I not bother because Rick was involved?
I made my suggestion based on tom's speculation that Rick might have an issue with his system. Rick's claim, then, becomes a symptom. That seemed a reasonable hypothesis to me (as opposed to sarcasm). Hypotheses are meant to be tested. Tom's hypothesis. The test would be to see if the power cord mattered once the incompetence was identified and rectified.
Of course an investigation is predicated on Rick's cooperation. If he doesn't... meh. It's his problem, not ours. But it's important to make the offer, no?
On the other hand, if it's a matter of sarcasm...
And I'm truly interested in an evaluation of the Galo PSU. I'm considering a version of it with transformer secondary snubbers (maybe instead of the diode caps) and the bridge connected signal ground from the Pearl II. Or should I not bother because Rick was involved?
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What if you happen to be on the wrong side of the genius/pigeon divide? Is it still funny? Or maybe it could be taken as very disrespectful?
Reads more like the latter to me.
What Rick had done right once is not a 'carte blanche' to claim with authority any BS he fancies.
In another thread, I asked what has happened to Rick Miller that once has identified, measured, and explained a problem, contributing to DIY audio.
Unfortunately, his current 'contribution' can't be distinguished from some troll efforts. It may be that his current employer’s 'business plan' requires such approach.
On the off-topic question, Galo's PS is fine. With input RF filter and common mode choke filters, you can't go wrong. Use good quality diodes and a snubber, instead of capacitors in parallel with diodes. You can go overboard with active rectifier like:
https://www.diyaudio.com/community/threads/ideal-bridge-rectifier-gb.333844/
https://www.diyaudio.com/community/threads/lt4320-based-active-rectifier.336572/
Aside from generally required politeness while discussing on this forum, respect can only be earned.
@tombo6
As I said, all I know about Rick is a favourable 1995 mention in TAA.
However, here I was responding to your hypothesis about how someone could experience differences in otherwise innocuous components -- such as cables etc. -- because of problems in the rest of their system. I think that's a reasonable hypothesis but evidently you weren't serious. Too bad.
I like the character of helpfulness that generally dominates this forum. It might help in this type of case... more than the aggression. Offer to help and require circuits and photos to start. A lack of response ends it. That's been my experience in other venues.
And who knows... you just might solve the cable controversy and put it to bed... forever. That's a useful goal.
Meanwhile we await photos... and get on with what matters.
Thanks for the observations on the PSU. The snubbers on the secondaries seem sensible.
As I said, all I know about Rick is a favourable 1995 mention in TAA.
However, here I was responding to your hypothesis about how someone could experience differences in otherwise innocuous components -- such as cables etc. -- because of problems in the rest of their system. I think that's a reasonable hypothesis but evidently you weren't serious. Too bad.
I like the character of helpfulness that generally dominates this forum. It might help in this type of case... more than the aggression. Offer to help and require circuits and photos to start. A lack of response ends it. That's been my experience in other venues.
And who knows... you just might solve the cable controversy and put it to bed... forever. That's a useful goal.
Meanwhile we await photos... and get on with what matters.
Thanks for the observations on the PSU. The snubbers on the secondaries seem sensible.
I referenced his work at post #415.
Your hypothesis is proper. If change in sound really exists it must have a physical cause which can be measured. We may struggle to determine what must be measured. There is no doubt that even measurement equipment of a hobbyist is orders of magnitude above resolution of human hearing. Psychoacoustic effects, or our brain interpretation of input, are mayor cause of disagreements. AFAIK, our resolution floor is about 60 dB below signal level.
I was serious and I would gladly discuss with someone interested to find why he perceives sound changes with different power cords, after confirmation that effect really exists. I’m supplying ignored measurements and receiving in return new wild claims with no evidence.
Now we are at copper wire burn-in changing sound. I have no doubts that next would follow cable direction, cryogenic treatment, and magic Shunyata KPIP burn-in device that makes power cords permanently 'sound better'.
Any reasonable person would ask what physical characteristic of wire can change after some usage or burn-in. What are change magnitudes and by what physical mechanism those changes can affect connected equipment and by what magnitude any change can be present at amplifier/loudspeaker output.
I don’t expect any answer as those that ‘hear’ a sound of wires are content with their beliefs that require no evidence whatsoever.
I’m content with Science confirming what I hear, after it was heard.
Your hypothesis is proper. If change in sound really exists it must have a physical cause which can be measured. We may struggle to determine what must be measured. There is no doubt that even measurement equipment of a hobbyist is orders of magnitude above resolution of human hearing. Psychoacoustic effects, or our brain interpretation of input, are mayor cause of disagreements. AFAIK, our resolution floor is about 60 dB below signal level.
I was serious and I would gladly discuss with someone interested to find why he perceives sound changes with different power cords, after confirmation that effect really exists. I’m supplying ignored measurements and receiving in return new wild claims with no evidence.
Now we are at copper wire burn-in changing sound. I have no doubts that next would follow cable direction, cryogenic treatment, and magic Shunyata KPIP burn-in device that makes power cords permanently 'sound better'.
Any reasonable person would ask what physical characteristic of wire can change after some usage or burn-in. What are change magnitudes and by what physical mechanism those changes can affect connected equipment and by what magnitude any change can be present at amplifier/loudspeaker output.
I don’t expect any answer as those that ‘hear’ a sound of wires are content with their beliefs that require no evidence whatsoever.
I’m content with Science confirming what I hear, after it was heard.
True for steady-state sine wave measurements. But how do you measure the quality of the stereo illusion during volume level transients? Its not steady-state. Its not one mono channel. Its not just crosstalk at 20kHz. AFIK we don't really have a good way of measuring it. What we are good at measuring are 'figures of merit.'
How would soundstage perception change if absolutely nothing has changed at both loudspeaker outputs. Ah yes, change is in the head of a listener. 😉
Those rambling about change with power cords are not only speaking of ‘focus of sound’, ‘space around instruments’, ‘lifted veils’ and so on. Often, specific changes in treble, mid and bass are mentioned.
On the system under observation, we do not perform only basic distortion measurements with stationary sinewave. We can measure intermodulation distortion, multitone distortion, square wave response, single pulse transient response, arbitrary complex single pulse response, dynamic linearity, amplifier signal propagation delay, phase response, noise, output impedance (damping factor), EMI presence and propagation through circuit …… all that with several basic instruments like good multimeter, oscilloscope, Low Noise Amplifier, dual channel arbitrary waveform generator and ADC/DAC like Focusrite.
Only some knowledge and interest in finding truth is required.
Those rambling about change with power cords are not only speaking of ‘focus of sound’, ‘space around instruments’, ‘lifted veils’ and so on. Often, specific changes in treble, mid and bass are mentioned.
On the system under observation, we do not perform only basic distortion measurements with stationary sinewave. We can measure intermodulation distortion, multitone distortion, square wave response, single pulse transient response, arbitrary complex single pulse response, dynamic linearity, amplifier signal propagation delay, phase response, noise, output impedance (damping factor), EMI presence and propagation through circuit …… all that with several basic instruments like good multimeter, oscilloscope, Low Noise Amplifier, dual channel arbitrary waveform generator and ADC/DAC like Focusrite.
Only some knowledge and interest in finding truth is required.
My first question.
Relative to what? I scan read it, then search for "ref" and "earth" and "ground". No results.
So who says where 0V is? The diagram is non-sensical without defining what the DC offset is offset relative to. In most domestic mains supplies the Neutral is usually terminated to Earth in the building, outside the building or at the local transformer station. You will find a few volts difference between your local earth and the Neutral. That isn't DC offset though, its caused by voltage drop on the lines between you and the point N is tried to E.
This is different again in the US as they typically get dual phase power to the home. In the UK phases are 240V and houses only get one.
The main issue with consumer electronics both causing the problem and making it entirely irrelevant. Switch mode power supplies. These cause 100s of times more issues on the local mains and other circuits than any wider mains related issues.
SWPSUs dump constant leakage between primary and secondary via Y class capacitors. This means, very literally, when you put on your fancy metal frame headphones connected to your lovely linear power supply, but being fed by a device running on a DC wall wort... that your headphones are live at about 100VAC (UK) relative to earth. I get this from my PC desktop speakers. 275uA of it too. I mean you are literally connected to the mains line voltage with a single tiny little blue Y class capacitor being the only thing between your ears and 240V mains.
PCs are notorious for just jumping that leakage to earth. This cuts the leakage massively by pulling it down to earth. However it adds noise to the mains earth and antagonises your Trip switches. That said, if it's not a cheap chinese import, it's likely it has had to pass EMC and EMF compliance tests. Too much HF noise on the earth line creates a lot of RF noise and interferes with everything including radio.
On measuring the impact noise has on your audio. Measure the audio band. Anything about 22K can be ignored unless it has harmonics below.
Now for the reality shock. Electric doesn't flow in wires. It flows in the electromagnetic fields held by the electrons in the wire. The net effect of this can be seen by placing a mosfet on a breadboard powering an LED and leaving the gate dangling in the breeze. It will react as you move your hands around and if you hold your hand over it and capture the output of hte mosfet on a scope you will see the 50Hz mains frequency in that field, you can even measure it across your own body. It's EVERYWHERE. The only time you will find the electromagnet field NOT happily bouncing at 50Hz (60Hz US) is during a power cut.
If you look at this general EMF field with a scope by looping the probe back on itself to create a little antenna and zooming in, you see a solid block of wide band noise modulated by that 50Hz mains field. Keep zooming in and you see all manor of stuff down at the 30mV range and below. From the 50Hz all the way up to 100s of MHz and if my scope went beyond it it will carry on into the Ghz and continue all the way up.
Dirty mains is far more likely to pre-wear your equipment trying to deal with the higher frequencies but you won't hear them. In fairness when an opamp in your circuit gets powered by a rail with a 5Mhz 30mV inductor spike it might play havoc with the opamps stability.
On scoping the mains. The issue is the scope ground clip is actually an earth clip effectively. So as soon as you attach it to the neutral you creates a N-E line fault. It probably only has a few volts, but it can carry a huge amount of current, depending on the topology of your PE in your locality. In my case it would be the current on the N wire that is going back to the transformer from my street that would see the scope as a short cut. Smoke will rise if it doesn't actually go bang.
The guerrilla way to fix that is to remove the earth from the scope. At your own risk.
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How about amplitude and phase coherence across both channels at all audio band frequencies during real music transient conditions at the amplifier output terminals, down to -120dB?
How about dac idle tones sweeping across the audio band in the time it takes to acquire an FFT? Its energy would be distributed across all bins and look like noise. How would you distinguish it from random noise?
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How about measuring effect of gravity waves on DAC clock jitter? 😉
Pull another one, we don’t hear at -120 dB levels.
Wait, you did pull another. 🤣
Why would I measure a sweeping tone with FFT?
Pull another one, we don’t hear at -120 dB levels.
Wait, you did pull another. 🤣
Why would I measure a sweeping tone with FFT?
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