Noise. That damned demon you may not even know about...

[oldvinyl]

If airborne, Aaronia sells lots of shielding mats, tapes and stuff to shield all from cabinets to whole rooms

High and low frequency shielding solutions - Aaronia AG

High-tech shielding materials with very high shielding performance. Made in Germany.

aaronia.com

Lots of options. Google "MuMetal", 3M makes one I used to line a CD player. Couldn't tell if it had any effect though. Sounded the same after putting it in.

 

[Kingrex]

The inverter fans are usually the noise. As soon as you put the inverter in a different room, you have to follow all the NEC. That means you need a contactor that has a control knob on the outside of the house fire dept can operate. As well as phenalic labels noting alternate power source.

 

[oldvinyl]

The inverter fans are usually the noise. As soon as you put the inverter in a different room, you have to follow all the NEC. That means you need a contactor that has a control knob on the outside of the house fire dept can operate. As well as phenalic labels noting alternate power source.

The switching devices also make their own noise (IGBT). That much current switching at 60Hz can sound almost like a hiss.

 

[microstrip]

I believe he did and post number 250.

In fact all he posted was a spectrum with very good harmonic distortion compared to what is typically seen in urban mains.

Not enough to substantiate his posts.

 

[wil]

In fact all he posted was a spectrum with very good harmonic distortion compared to what is typically seen in urban mains.

Not enough to substantiate his posts.

Could you go into a little detail as to why this illustrates a good spectrum/level of distortion? Is there an overall % thd that can be calculated from this?

And, @Amir, is there a sine wave you can share?

 

[microstrip]

Could you go into a little detail as to why this illustrates a good spectrum/level of distortion? Is there an overall % thd that can be calculated from this?

And, @Amir, is there a sine wave you can share?

Amplitude is a dB scale - the amplitudes can be easily converted to a perceptual ratio. The higher harmonic peak (fifth harmonic) is around - 37 dB , about 1.5% harmonic distortion. No calculator is needed - ChatGPT can do all calculus for us. THD can easily be done from the individual components using a root of squares sum formula.

 

[wil]

Amplitude is a dB scale - the amplitudes can be easily converted to a perceptual ratio. The higher harmonic peak (fifth harmonic) is around - 37 dB , about 1.5% harmonic distortion. No calculator is needed - ChatGPT can do all calculus for us. THD can easily be done from the individual components using a root of squares sum formula.

Is the 1.5 % distortion only for the 5th harmonic? In other words, to get a THD level, would we be adding all the other harmonics to get a significantly higher distortion level?

 

[DasguteOhr]

Is that a power distribution box with captured male ends. I like it. I built similar. its the best distribution I have hear in my system. So much better to get rid of duplex.

Minimize plug contacts, only one grounding point (copper rail) is optimal for me. Choose the IEC plug and sockets (device) well, high copper content, heavily silvered (kaiser plug), phonosophie use it. prominent contact surface sounds better then most expensive plugs.

Kaiser IEC plug, Silver-plated | HIFICollective

Kaiser IEC plug, Silver-plated

www.hificollective.co.uk

Phonosophie Power Cord Netzkabel - Ag Stecker (Phonosophie Sicherungen + Strom)

Phonosophie Power Cord Netzkabel - hochwertiges Stromanschlusskabel für Audio Video HiFi-Geräte mit Kaltgerätestecker.

www.hifi-zubehoer.shop

Pure copper awg 13 cable without shielding. Sounds open ,quick and detailed

 

[Amir]

Again, if you specify and quantify your claims they can have some meaning. Otherwise they rank with Armageddon claims.

You are in whatsthebestforum not ASR forum so we share our subjective experience. My claims come from my listening experience. If you have any any experience please share and we talk about that.

Why not 100 kVA? Even applying a logarithmic factor considering the law of diminishing returns it will probably sound around two times better.

I checked my system from 3kva up to 20kva , the linear psu of high power class ab amplifiers draw high current at very short time so your inverter system should be linear even at high current delivery.

FM acoustics wrote the AC power should be linear (low distortion) when deliver 90A current

 

[Amir]

How many watts does your audio system require?

Under 1000w rms

 

[Amir]

Could you go into a little detail as to why this illustrates a good spectrum/level of distortion? Is there an overall % thd that can be calculated from this?

And, @Amir, is there a sine wave you can share?

Sorry, No I do not have sinewave pictures to share.

I think simple objective measurements of ac power do not help us. What we need is to show problems of ac power may be far more complex measurements.

audio never sounded like measurements

 

[wil]

Sorry, No I do not have sinewave pictures to share.

I think simple objective measurements of ac power do not help us. What we need is to show problems of ac power may be far more complex measurements.

audio never sounded like measurements

In any case, it does seem your experience indicates isolation from the mains would be a good idea.

 

[wil]

Bingo!
I have some rather large Class A SET amps. Just in those monoblocks I need 800 watts. Add another 600 watts when I biamp. The phono stage is all tube and uses 700 watts. That's 2100 watts! Not sure I want that kind of battery and invertor in the listening room. Invertors are noisy.

I’m only pulling 320 watts, so my 2000 watt inverter’s fan does not come on very often. My original plan watt to put the inverter in a nema outdoor enclosure, but I don’t think it’s necessary now.

 

[microstrip]

Is the 1.5 % distortion only for the 5th harmonic? In other words, to get a THD level, would we be adding all the other harmonics to get a significantly higher distortion level?

THD is computed using RMS algoritm. Ask ChatGPT "How do we calculate a RMS value?" It will give you a proper answer with a nice example - probably the typical 2, 3, 4 and RMS or them is 3.11

Then ask the bot how to calculate THD using RMS.

 

[wil]

I don't have ChatGPT.

Looking at the spectrum from 1st through about the 11th. (very difficult to read low res picture). As best I can tell:

3rd. -42 db
5th. -36
7th. - 39
9th. -45
11th -45

Just generally speaking (no formulas please!), should we extrapolate your conclusion of 1.5%. harmonic distortion on the 5th harmonic to mean that the total harmonic distortion when calculated would be a higher, lower or about the same %?

Thanks

 

[Holmz]

I don't have ChatGPT.

Looking at the spectrum from 1st through about the 11th. (very difficult to read low res picture). As best I can tell:

3rd. -42 db
5th. -36
7th. - 39
9th. -45
11th -45

Just generally speaking (no formulas please!), should we extrapolate your conclusion of 1.5%. harmonic distortion on the 5th harmonic to mean that the total harmonic distortion when calculated would be a higher, lower or about the same %?

Thanks

A bit higher, but not a lot.

 

[wil]

A bit higher, but not a lot.

So, as per the thread subject: this seems to illustrate the difficult to diagnose and mysterious nature of noise and audio.

Everything Amir reports about his sound, from the erratic nature at different times of day, to the fact that he lives in a building sharing the grid with 200 other tenants would indicate his power is being undermined. I’m surprised it doesn’t show and his THD measurements.

 

[microstrip]

I don't have ChatGPT.

Looking at the spectrum from 1st through about the 11th. (very difficult to read low res picture). As best I can tell:

3rd. -42 db
5th. -36
7th. - 39
9th. -45
11th -45

Just generally speaking (no formulas please!), should we extrapolate your conclusion of 1.5%. harmonic distortion on the 5th harmonic to mean that the total harmonic distortion when calculated would be a higher, lower or about the same %?

Thanks

Just use google - it is an RMS value, many sites will explain it. Or go through https://www.allaboutcircuits.com/technical-articles/the-importance-of-total-harmonic-distortion/ . We can consider it should the about the same, just a little higher, the square sum smooths it.

 

[microstrip]

So, as per the thread subject: this seems to illustrate the difficult to diagnose and mysterious nature of noise and audio.

Everything Amir reports about his sound, from the erratic nature at different times of day, to the fact that he lives in a building sharing the grid with 200 other tenants would indicate his power is being undermined. I’m surprised it doesn’t show and his THD measurements.

THD is just a small part of it. We do not even know the VRMS fluctuations of the mains and the mains supply resistance. If the ground is shared with 200 other tenants it is probably a good source of noise!

 

[Holmz]

So, as per the thread subject: this seems to illustrate the difficult to diagnose and mysterious nature of noise and audio.

Everything Amir reports about his sound, from the erratic nature at different times of day, to the fact that he lives in a building sharing the grid with 200 other tenants would indicate his power is being undermined. I’m surprised it doesn’t show and his THD measurements.

^Incorrect.^
It illustrates that whatever is happening on the incoming power may or may not have anything to do with what is happening in the poer supply rails or the ground.
If it did then all we would hear are 60 or 120 fundamental, or 50/100 in more other countries.

A lot of the mysterious nature of “it” is that it has a heavy marketing spin.
The fact that demon is used in the title just reinforces the supernatural spin.

One either gets an 0-scope… or they abide the marketing, mystery and spin.