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

[Kingrex]

. if i ever build another room i will have another Equi=tech wall panel system.

Depends on where your listening room is. If inside a residence, all branch wires going through or behind a wall need to be AFCI protected. There is no AFCI listed and labeled to operate on a "Balanced" power line. So its not going to be a permited installation.

Its possible you could put the transformer in your listening room and run cables in surface wireways to outlets. You might get away with that. Or use a Torus. Those can be configured with AFCI output breakers.

 

[Mike Lavigne]

Depends on where your listening room is. If inside a residence, all branch wires going through or behind a wall need to be AFCI protected. There is no AFCI listed and labeled to operate on a "Balanced" power line. So its not going to be a permited installation.

Its possible you could put the transformer in your listening room and run cables in surface wireways to outlets. You might get away with that. Or use a Torus. Those can be configured with AFCI output breakers.

the Equi=tech came with GFI's on each branch inside the Wall Panel unit. i had the contractor replace them with a straight wire to reduce noise. he did it since there is no water inside the room and it's a semi-commercial specific use installation with no children using it. and i have a separate 'dirty power' circuit and outlets inside the room with GFI's.

but i understand the difference if my next room is inside the residence. at this point unknowable.

 

[microstrip]

I agree with you Wil. But he needs all 4 tools your are using. Not just a scope. The scope is too limited. It does not tell you RF and EMI also.

We just need an USB soundcard (less than $200) and some software.

And surely a life insurance is advised if we do not know how to deal with mains power ...

 

[microstrip]

(...) and it's possible i might have different amps by the time you are ready to do it. and those new amps run mostly class A so need a bit more juice.

In fact, class A amplifiers should be less dependent on mains supply. They drain a constant current, so they do not cause mains voltage fluctuations due to music dynamics, except if you run them so loud they enter class B.

 

[microstrip]

From what you have shared with me, you are measuring with a
Alpha Lab EMI meter
Entech for RF
Shure Test for Current
And a Fluke scopemeter for THD and low level harmonics.

That is a pretty good set of inexpensive tools that will give you a good general idea what issues you are experiencing. The Alpha Lab and Entech are not that accurate. Sort of a shot gun approach. They tell you if noise is there. Just not what the actual frequency of the noise is. But, how granular is the consumer trying to get. If you know you have noise, and you plug in a filter, your going to be able to retest and see if the noise is gone. That is all we really want to know .

Unfortunately the EMI and RF tools you refer are inadequate and can be very misleading, triggering us in false conclusions. Not very different from the scientist and the frog.

At some time in the past I had access to a decent RF spectrometer, but their current price is around $3000 ... The Siglent SSA3032X‑R or even better the Tektronix RSA306B are my dream on the subject.

 

[Kingrex]

We just need an USB soundcard (less than $200) and some software.

And surely a life insurance is advised if we do not know how to deal with mains power ...

Would you share the software you use?

 

[Holmz]

I don't understand what you mean with the voltages on A, B, C. Chassis Voltage???

I thought you were Iran and using European 240 volt on a single phase leg. Or do they use Split phase 120/240 like the US and Canada?

US is like push-pull - so it is like an XLR for power.
The rest of the world is single ended, so it is live and return.

 

[microstrip]

Would you share the software you use?

SpectraPlus - you can use the complete demo version for 30 days.
https://www.spectraplus.com/

 

[microstrip]

I don't understand what you mean with the voltages on A, B, C. Chassis Voltage???

Probably leakage chassis voltage measured with a floating ground.

I thought you were Iran and using European 240 volt on a single phase leg. Or do they use Split phase 120/240 like the US and Canada?

Iran has the same type of power as most Continental Europe - 230Vac .

You could also be suffering from Peaks and Sags. Sags will suck the power out of your system. Atmasphere was talking how a few volts under 120, like say 117 diminished the power supply in an amp by like 25% or some insanely large number. A isolation transformer can not help that. Only a UPS, Regenerator or Battery/Inverter can. The UPS has to be configured properly also. It can pass through sags, swells and noise also. Only when it goes into backup power and uses the battery and inverter is it offgrid. Otherwise its on grid waiting for an extreme event where it needs to click into safe mode and use the battery for a short period of time.

I have looked into Pure Power and talked to a few people. Oddly a few said an older model that was very small sounded best. The larger models were not as good sounding. I did not understand why that might be at the time.

Without proper diagnostic, all we can do is speculating.

 

[Amir]

Amir, I am no authority on power problems and can only speak from my experience and, hopefully, logic.

From what you are telling us, you have a very severe AC issue supplying your system that is ruining any chance of getting reliably good sound. I can’t think of anything else that would be causing what you describe.

It seems clear, you need to get off the grid and the simplest and most effective way of doing that is through a properly sized, high-quality LPO battery and low distortion inverter.

I also think, again, you need to get your hands on a fluke scope to see what you’re dealing with on your AC power

Thanks, This is my 50hz 230v spectrum :




I agree with you I should go for battery inverter.

My showroom is in a big complex and building ac power shared between 200 apartments. It means around 200 refregrator , many leds and many switching psu and … all are connected to this ac power so I shoulc forget this ac power and go for battery inverter.

 

[Amir]

I don't understand what you mean with the voltages on A, B, C. Chassis Voltage???

I thought you were Iran and using European 240 volt on a single phase leg. Or do they use Split phase 120/240 like the US and Canada?

You could also be suffering from Peaks and Sags. Sags will suck the power out of your system. Atmasphere was talking how a few volts under 120, like say 117 diminished the power supply in an amp by like 25% or some insanely large number. A isolation transformer can not help that. Only a UPS, Regenerator or Battery/Inverter can. The UPS has to be configured properly also. It can pass through sags, swells and noise also. Only when it goes into backup power and uses the battery and inverter is it offgrid. Otherwise its on grid waiting for an extreme event where it needs to click into safe mode and use the battery for a short period of time.

I have looked into Pure Power and talked to a few people. Oddly a few said an older model that was very small sounded best. The larger models were not as good sounding. I did not understand why that might be at the time.

Yes, the chassis voltage, when you connect an equipment to ac line without connecting the earth wire then there is a voltage between chassis and the earth. Changing ac polarity change the chassis voltage.

In Iran we do not use split voltage, here the single phase voltage is 230 volts.

Purepower company introduced 2000 and 3000, I have both, I think 2000 is a bit better.

It seems the sound of battery/inverter is more affected by battery, both Dartzeel and ASR Audio use battery for low level signal stages, they also use batteries with dc circuits (capacitor + dc filter + …). I think ASR dc circuit change the game and improve the sound of battery.

 

[MarkusBarkus]

when you connect an equipment to ac line without connecting the earth wire then there is a voltage between chassis and the earth

...do you mean *potential* voltage between chassis and earth? As long as there is no other path to earth-ground, there is no flow of current, right? I think that is why devices like Shunyata Altaira are *not* recommended for such equipment, e.g. Luxman gear, which arrives in the US with a three-prong plug/cable, although the earth ground is not connected at the IEC inlet.

 

[Amir]

...do you mean *potential* voltage between chassis and earth? As long as there is no other path to earth-ground, there is no flow of current, right? I think that is why devices like Shunyata Altaira are *not* recommended for such equipment, e.g. Luxman gear, which arrives in the US with a three-prong plug/cable, although the earth ground is not connected at the IEC inlet.

when there is no path to the earth you can measure the voltage (chassis voltage) and if you connect the chassis to the earth then you can measure the leakage current.

This voltage is related to power supply capacitance and it will change if you change the ac polarity.

I did not read about Altaira, if Altaira cleans the earth then it is not useful for class II appliance.

these articles are about noise and SNR :

https://amiraudio.com/wp-content/uploads/2023/02/TB_05-R2.pdf

https://cdn.shopify.com/s/files/1/0321/7609/files/caig.pdf?264

https://indianaaes.org/wp-content/uploads/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

https://www.russandrews.com/images/pdf/GroundingGuideV7.pdf

 

[Amir]

One important thing is when you change the AC polarity then the lowest chassis voltage (equal to lower noise) is not always the best sound.

Some articles from Jim Aud and TAS claims the lowest voltage (or lowest leakage current) is best but it is not. You should listen to both and decide which is better.

 

[DasguteOhr]

One important thing is when you change the AC polarity then the lowest chassis voltage (equal to lower noise) is not always the best sound.

Some articles from Jim Aud and TAS claims the lowest voltage (or lowest leakage current) is best but it is not. You should listen to both and decide which is better.

It is a complex procedure. Disconnect the ground (earth)from all power cables and then measure. but it's worth it the noise level is significantly lower. and you only need to do it once and mark it.is always the first step before connecting the devices with signal cables.

Attention at the moment of measurement there is no protection function against fatal electric shock

 

[Kingrex]

It is a complex procedure. Disconnect the ground (earth)from all power cables and then measure. but it's worth it the noise level is significantly lower. and you only need to do it once and mark it.is always the first step before connecting the devices with signal cables.

Attention at the moment of measurement there is no protection function against fatal electric shock

And if its fine today, it could fault tomorrow and become fatal. Better to use something like a Ebtech HumX. Its back to back Diode that with enough current, will pass the current and open the breakers. With no current, it will remain open and act like a stereo with no ground. That is really the only safe way to lift the ground of equipment that is intended to have a ground connection.

 

[DasguteOhr]

And if its fine today, it could fault tomorrow and become fatal. Better to use something like a Ebtech HumX. Its back to back Diode that with enough current, will pass the current and open the breakers. With no current, it will remain open and act like a stereo with no ground. That is really the only safe way to lift the ground of equipment that is intended to have a ground connection.

Everything's fine, it's just a matter of finding the right polarity. As long as the circuit ground and earth connection have a connection in the device, there are no correct values.after mesurement then the ground is reconnected and works again.

 

[Kingrex]

Everything's fine, it's just a matter of finding the right polarity. As long as the circuit ground and earth connection have a connection in the device, there are no correct values.after mesurement then the ground is reconnected and works again.

What are you trying to figure out?
If you see different potential, are you supposed to try and change something to bring them closer.

And were talking, grounded equipment, correct. As in the plug has a earth ground that the circuit is attached to. Or a ungrounded system where the equipment is 2 prong, no earth ground.

 

[DasguteOhr]

What are you trying to figure out?
If you see different potential, are you supposed to try and change something to bring them closer.

And were talking, grounded equipment, correct. As in the plug has a earth ground that the circuit is attached to. Or a ungrounded system where the equipment is 2 prong, no earth ground.

Of course about grounded devices, it's about the plug polarity or main transformer in the device and the correct polarity of the secondary winding in the circuit. If it is grounded it will not give a correct measurement. Do it as described and you will see that there is sometimes a difference of 80 volts and more at mesurements.As long as the device is grounded there is always potential equalization

 

[Amir]

no need to measure leakage current or chassis voltage when we can listen to music in both ac polarity (proper and inverted) and choose which sounds better