Why are my USB audio devices flaky?

[amano]

If it’s not audible, it doesn’t affect your amplifier..

It is just my little game. People buy amplifiers with extremely high SINAD scores even if higher SINAD scores are not audible. Beyond SINAD score of 60 or 80, it's probably not audible.

I buy better measurement numbers when it's not expensive or time-consuming to buy the numbers. Because I'm broke at the moment, I'm a cheap numberphile. When I have money, I won't be cheap.

 

[voodooless]

It is just my little game.

Then why:

Clean power in the house wires can help with audio quality.

 

[wwenze]

I avoid ETA/80PLUS-certified activePFC power supplies which tend to inject a lot of EMI into the house wires that affect my amplifier.

Non-certified activePFC power supplies inject less.

Power supplies without activePFC inject even less, but you may pay more for electricity due to lower power factor if power company charges you for lower power factor. However, unless you are running a bitcoin mining farm, you aren't going to worry about electricity bills.

Clean power in the house wires can help with audio quality.

Opposite is true. Power supplies have APFC as a result of EU and US requirements and these requires also include lower harmonics injected back into AC. Without these features the charging current is just a sharp spike with low correlation to the AC voltage.

Also house customers are not billed for low power factor.

 

[amano]

Power supplies have APFC as a result of EU and US requirements and these requires also include lower harmonics injected back into AC. Without these features the charging current is just a sharp spike with low correlation to the AC voltage.

Most ActivePFC power supplies don't bother to sufficiently filter out high-frequency noises created by ActivePFC.

Where do I find ActivePFC power supplies that actually care about filtering out high-frequency noises? I haven't found one, yet.

I'd say you need a better technology than ActivePFC or a better EMI filter specifically designed for ActivePFC circuits.

 

[amano]

Then why:

I say better measurements. Better audio quality is not necessarily audible. You are not going to hear the difference between SINAD 80 and SINAD 110.

 

[mcdn]

I say better measurements. Better audio quality is not necessarily audible. You are not going to hear the difference between SINAD 80 and SINAD 110.

And your choice of PC power supply and mains cabling isn’t going to have any measurable effect on your amp SINAD. Certainly not 30dB like you imply.

 

[Sokel]

Most ActivePFC power supplies don't bother to sufficiently filter out high-frequency noises created by ActivePFC.

Where do I find ActivePFC power supplies that actually care about filtering out high-frequency noises? I haven't found one, yet.

I'd say you need a better technology than ActivePFC or a better EMI filter specifically designed for ActivePFC circuits.

How do you light your rooms?
Any fridge in the house? HVAC?
One or three phase el. installation?

 

[amano]

And your choice of PC power supply and mains cabling isn’t going to have any measurable effect on your amp SINAD. Certainly not 30dB like you imply.

Let's not focus too much on my power supply choice if it's not critical to my issue.

I am here to solve actual problems, not decide who's right about non-critical matters.

How do you light your rooms?
Any fridge in the house?
One or three phase el. installation?

I don't know whether they are ActivePFC. According to my measurement, LED lighting and fridge weren't creating a lot of EMI probably because their load was largely linear. Computers aren't linear in their load.

And, let's not focus too much on my power supply choice. In any case, not using an ActivePFC power supply is not going to create an issue. I'm going to investigate my issue my way independently.

Do we have to spend hours on ageeing on every little thing in order to move on and fix real issues? The real issue was USB audio devices dropping in and out. My power supply choice is my preference based on my measurements.

If my personal preference(reducing measurable high-frequency noise) doesn't create an actual issue, let's not waste time.

 

[Sokel]

Let's not focus too much on my power supply choice if it's not critical to my issue.

I don't know whether they are ActivePFC. According to my measurement, lighting and fridge weren't creating a lot of EMI probably because their load was largely linear. Computers aren't linear in their load.

And, let's not focus too much on my power supply choice. In any case, not using an ActivePFC power supply is not going to create an issue. I'm going to investigate my issue my way independently.

Do we have to spend hours on ageeing on every little thing in order to move on and fix real issues?

I ask cause I have measured and see what these things can do.
The worst of all by far are motors and led lighting if using a shared installation. Orders of magnitude worst.

I wouldn't worry about the PSU if I were you, I can show you measurements with activePFC PSU used that is clean as a whistle.
Sane ground practice, etc are far more important.
Listen to @AnalogSteph , he knows more than the rest of us combined.

 

[amano]

I wouldn't worry about the PSU if I were you, I can show you measurements with activePFC PSU used that is clean as a whistle.

My measurements are the opposite. I probably use a different measurement equipment or different PSUs.

Listen to @AnalogSteph , he knows more than the rest of us combined.

Again, if non-activePFC or passivePFC doesn't actually create an actual problem, let's not fuss over it too much. I don't want to continue discussing my power supply choice.

Are we here to solve actual problems or waste time on proving who knows more? I want to form my own conclucions without constant social pressure.

If I buy non-activePFC power supplies, are you going to lose money or freedom? If not, why obsess over it so much?

 

[amano]

We are not going to agree on anything by exchanging vague arguments. I'm pretty much sure that it will take 5 years to convince anyone of anything in many cases. So, let's stop discussing my power supply choice. Please stop. We can waste the next 5 years on this tiny topic, or we can move on.

 

[BeeKay]

Sane ground practice, etc are far more important.
Listen to @AnalogSteph , he knows more than the rest of us combined.

You can lead a horse to the water …

 

[wwenze]

Considering how this thread has gone I can no longer be sure that flaky USB connection isn't caused by common-mode noise from usage of unqualified power supplies that break every first world country's electrical codes.

 

[Sokel]

As a side note that's how an active PFC looks like through an ancient PC powered interface.
No isolators, no nothing, signals and conditions on chart, all unbalanced:

 

[BeeKay]

Please stop.

@Sokel crossing the Rubicon

 

[mcdn]

@amano Is the problem fixed since you blew the dust out, or do you still have issues? It's not quite clear from your earlier post.

Even if things are working you clearly have an issue with one or more of:

• your PC power supply
• your mains arrangements
• your motherboard voltage regulation
• your motherboard's ability to supply sufficient current over USB

This is evidenced just from the BIOS itself reporting severe under voltage on the MB 3.3V rail, as well as the original flakiness you had a problem with, and the low voltage on the 5V pin.

You also had intermittent problems when USB connectors were being nudged about. This is suggestive of a grounding issue somewhere which may not be fixed yet.

 

[amano]

After vacuuming dust, my flaky USB ports became robust. Now, nudging USB plugs doesn't cause USB devices to drop in and out.

Considering the fact that dust was causing RAM errors, this is possible.

This is suggestive of a grounding issue somewhere which may not be fixed yet.

USB ports are not flaky after vacuuming dust.

This is evidenced just from the BIOS itself reporting severe under voltage on the MB 3.3V rail

This is possibly a sign of a failing power supply which lived years beyond its warrantee. However, after vacuuming dust, USB ports are not flaky anymore. My system seems stable.

UEFI sensors may not be accurate. If they are accurate, it's simply time to buy a new power supply. I don't expect power supplies to live long beyond warrantee without issues.

the low voltage on the 5V pin.

It floats above 4.9V. It is fine.

 

[amano]

usage of unqualified power supplies that break every first world country's electrical codes.

You don't know much about my power supply. I know you don't care about me or my power supply. I know about my power supply better than you do.

You don't know that about my power supply.

 

[kyuu]

You can do what you want, but AnalogSteph is highly experienced and knowledgeable on these topics so you'd do better to listen than to get defensive as though attempting to help you solve a problem is some kind of personal attack.

 

[AnalogSteph]

Bill Whitlock is your friend when it comes to hunting down common-mode issues.
UNDERSTANDING, FINDING, & ELIMINATING GROUND LOOPS IN AUDIO & VIDEO SYSTEMS

BTW, some people have had flaky USB from ground loops running through their front panel.