Impact of AC Distortion & Noise on Audio Equipment

[Doodski]

Amir, my point was you tested "one device at a time", not that you only tested one device.

All my living room equipments, including the amps and subs, are connected to my power conditioners. I would love it if you can do a "whole chain" comparison vs "one at a time" comparison.

What is going to occur is the same result up until the max current is used and then the B&K "circuit breaker" is going to engage or the B&K will limit the current. The AC waveform is not going to change and the test result is not going to change either.

 

[Pdxwayne]

What is going to occur is the same result up until the max current is used and then the B&K "circuit breaker" is going to engage or the B&K will limit the current. The AC waveform is not going to change and the test result is not going to change either.

No, I am not even going to ask Amir to simulate dirty AC.

I am not going to ask Amir to use his expensive measurement equipment either. That very expensive equipment is not representative of typical source equipment.

All I am asking is this:
Use a regular chain, like those normal people use, player, DAC, ADC, computer, etc, all plugged to wall. Capture audio from that chain.

Plug everything into a good AC conditioner. Capture audio from the chain.

Compare the captured audio using null software.

Amir can easily handle this.

 

[b4nt]

all plugged to wall.

That makes no sense. What we each get out from our walls is different, over time, time of day also.

Such a test would need at least two runs:
- one with a very nice sine and no noise at all to evaluate the chain
- then with simulated dirty AC, using common known noises paterns

If the dirty AC isn't simulated, tests cannot be reproduced.

 

[Pdxwayne]

That makes no sense. What we each get out from our walls is different, over time, time of day also.

Such a test would need at least two runs:
- one with a very nice sine and no noise at all to evaluate the chain
- then with simulated dirty AC, using common known noises paterns

If the dirty AC isn't simulated, tests cannot be reproduced.

Why not makes sense? When do we get totally clean AC in our home?

 

[RayDunzl]

Can I save on my electric bill if I run my gear on dimmers?

 

[b4nt]

Why not makes sense? When do we get totally clean AC in our home?

Amir's wall outlet may be cleaner than yours. You wouldn't like the results. Or others may protest.

If a setup is powered by dirty but well defined simulated AC, the test bench would be more close to every one's outlet. And the test could be reproductible over time, in different locations also.

 

[Pdxwayne]

Amir's wall outlet may be cleaner than yours. You wouldn't like the results. Or others may protest.

If a setup is powered by dirty but well defined simulated AC, the test bench would be more close to every one's outlet. And the test could be reproductible over time, in different locations also.

It was mentioned that the simulation device lacks enough power to power everything. So, it won't be representative anyway.

People already complaining, so another data point won't hurt.
: P
Amir can always select a room that he thinks will have most noise and most representative of a typical room of users of power conditioner.. Maybe test in his AV setup room, etc.

 

[b4nt]

It was mentioned that the simulation device lacks enough power to power everything. So, it won't be representative anyway.

People already complaining, so another data point won't hurt.
: P
Amir can always select a room that he thinks will have most noise and most representative of a typical room of users of power conditioner.. Maybe test in his AV setup room, etc.

It isn't a question of room, but of what might come out of an outlet. I think I've seen 3k and 6kW simulators. Shoudn't be the problem. But would cost a lot (in rental for a week duration also).

 

[amirm]

All I am asking is this:
Use a regular chain, like those normal people use, player, DAC, ADC, computer, etc, all plugged to wall. Capture audio from that chain.

Plug everything into a good AC conditioner. Capture audio from the chain.

Compare the captured audio using null software.

Amir can easily handle this.

Why don't you do it? What do you need me for? If you don't have an ADC, get an interface. You can have one for much less money than what these conditioner companies charge.

Keep in mind that you need to synchronize samples with a tool like detawave. Otherwise they won't null even if you don't change anything.

 

[Pdxwayne]

Why don't you do it? What do you need me for? If you don't have an ADC, get an interface. You can have one for much less money than what these conditioner companies charge.

Keep in mind that you need to synchronize samples with a tool like detawave. Otherwise they won't null even if you don't change anything.

I did it already with node2i, DAC, adc, and laptop. One thing noticeable was clock drift.
See
https://www.audiosciencereview.com/...on-noise-on-audio-equipment.25501/post-871115

Yes, I was using deltawave to compare. Now is your turn, maybe capture at speakers end, like how @pma does it in https://www.audiosciencereview.com/...files-recorded-for-download.25646/post-874503
: )

What I didn't mention in that post is that, when compared capture with wall jack vs captures with power conditioner, the clock drift was larger, at 0.13pmm.

 

[b4nt]

@Pdxwayne For your tests, there you may request a quote for a programmable 2kVA AC source 3 weeks rent (plus shipping and insurances): https://www.axiomtest.com/Power-Sup...Source,-0-to-300V,-15-to-1kHz,-2kVA,-1-Phase/

You will also need an AWG. And test patterns. Would be a big effort, not only for costs.

 

[DeepSpace57]

Does he still have +115V with a 15V adapter? The box features two valves, their filaments probably being powered in serie. At 15V, this could be up to 7V5 per filament, too much...

That is probably a different aspect. Depending of the adapter one uses, he may get out more or less better or different sound. This being reasonable tweaks using cheap solutions, to get out the best. As long as the bundle dosn't cost much more.

Power section inside that unit seems basic. But the Loxjie P20 may feature 0.02% to 0.006% ?

No theme reviews

Link is here

 

[pkane]

What I didn't mention in that post is that, when compared capture with wall jack vs captures with power conditioner, the clock drift was larger, at 0.13pmm.

You do realize what a 0.13ppm drift value represents, right? It's a 0.005Hz difference in clock speed @44.1kHz. In other words, the clock was running at 44,100.005Hz instead of 44,100Hz. Even if this value was not due to some random, run-to-run variation/noise, it's too insignificant, and completely inaudible.

 

[audio2design]

No, I am not even going to ask Amir to simulate dirty AC.

I am not going to ask Amir to use his expensive measurement equipment either. That very expensive equipment is not representative of typical source equipment.

All I am asking is this:
Use a regular chain, like those normal people use, player, DAC, ADC, computer, etc, all plugged to wall. Capture audio from that chain.

Plug everything into a good AC conditioner. Capture audio from the chain.

Compare the captured audio using null software.

Amir can easily handle this.

I would throw a dimmer connected to an LED light to the AC plug as well (before and after the conditioner). Set it to trigger at 90 degrees.

 

[Pdxwayne]

You do realize what a 0.13ppm drift value represents, right? It's a 0.005Hz difference in clock speed @44.1kHz. In other words, the clock was running at 44,100.005Hz instead of 44,100Hz. Even if this value was not due to some random, run-to-run variation/noise, it's too insignificant, and completely inaudible.

Sure, I do understand about not audible part of clock drift.

Now, how about the difference of original spectral?

This is capture 1 vs capture 2, using just Furman:

This is Furman vs wall jack:

 

[audio2design]

I did it already with node2i, DAC, adc, and laptop. One thing noticeable was clock drift.
See
https://www.audiosciencereview.com/...on-noise-on-audio-equipment.25501/post-871115

Yes, I was using deltawave to compare. Now is your turn, maybe capture at speakers end, like how @pma does it in https://www.audiosciencereview.com/...files-recorded-for-download.25646/post-874503
: )

What I didn't mention in that post is that, when compared capture with wall jack vs captures with power conditioner, the clock drift was larger, at 0.13pmm.

Clock drift is far more likely to be equipment heating / cooling.

 

[pkane]

Sure, I do understand about not audible part of clock drift.

Now, how about the difference of original spectral?

This is capture 1 vs capture 2, using just Furman:
View attachment 147215


This is Furman vs wall jack:

View attachment 147216

That seems to be right at the limit of your ADC capability, which is somewhere around -103dB THD+N and both results are right around there. Did you take a number of captures with each AC source, so you can see if it’s just a run-to-run variability?

 

[audio2design]

Doesn't matter--nobody's going to hear it, and if they did, then there is no solution but to buy something better.

Being bad on purpose doesn't mean it isn't bad. I don't think even the euphonic-distortion crowd would be happy with the >1% THD that I see on that plot, but in any case, the manufacturers of those products probably claim far better. Power-line intermod that's 50 dB below that doesn't seem the worst sin there.

An otherwise transparent amp with that same crappy power supply and resulting intermod would report a distortion peak of -90 dB, which actually isn't bad. But it would report that in all of Amir's test cases of clean(ish) power, distorted power, and dirty power. The intermod is baked in, for better or worse, not the product of crappy supplied power.

Rick "not interested in noise above about 24 KHz" Denney

In most cases they probably would not even know there was 1% THD depending on the distortion profile. I would be more concerned with IM induced by poor PSR. Poor PSR can cause higher IM (not between power harmonics and signal but from two signals). Its not baked in in that respect.

 

[Pdxwayne]

That seems to be right at the limit of your ADC capability, which is somewhere around -103dB THD+N and both results are right around there. Did you take a number of captures with each AC source, so you can see if it’s just a run-to-run variability?

Nope. : P

I think I should do 2 minutes files anyway instead of 1 minute.

Will see if I have time later this week to check using gustard x16 using 2 minutes file.

 

[b4nt]

I would throw a dimmer connected to an LED light to the AC plug as well (before and after the conditioner). Set it to trigger at 90 degrees.

What are the dimmers usefull for? I have here 4 PCs running, other sleeping, some 10 SMPS active/connected around me, plus ethernet over CPL. Plus my fridge. And no mains conditionner.