Impact of AC Distortion & Noise on Audio Equipment

[Raindog123]

The problem with battery is that you need to charge it and with it, you are hooked up to mains. If you do bank switching, then the switches leak

One flip of a commercial $3 USB switch conveniently disconnects my battery (powering everything but the power amp) charger during a listening session:

 

[solderdude]

The problem is... a battery pack basically is an SMPS (and not the cleanest one either) it is not really battery power.
The battery powers a small SMPS inside (battery voltage can be between 2.7V and 4.1V depending on charge level)
The only difference is it is no longer connected to mains via the obligatory small Y-caps in the cheap power supplies that is there to comply to FCC rules.

 

[b4nt]

The problem is... a battery pack basically is an SMPS (and not the cleanest one either) it is not really battery power.

I would be more convinced by one powering all its audio devices using linear regulators fed by a huge lead battery set, feeding 48/24/12V. There would be no more noises related to AC.

 

[Raindog123]

…it is no longer connected to mains

Say no more!

And BTW, there are all kinds of battery packs out there, from those with regulated PS to simply banks of cells…

 

[Raindog123]

I would be more convinced by one powering all its audio devices using linear regulators fed by a huge lead battery set, feeding 48/24/12V. There would be no more noises related to AC

Totally doable… Yet loops us back to the initial question of the need for it. Might be a benefit in some (pathological?) dirty-mains-power cases, while a totally unnecessary eye (brain?) candy for most…

 

[b4nt]

Totally doable… Yet loops us back to the initial question of the need for it. Might be a benefit in some (pathological?) dirty-mains-power cases, while a totally unnecessary eye (brain?) candy for most…

I added this cause a big set of batteries would be the only way to kill all AC/mains lines noises.

A lot of chances to get EM interference as a measurement error

I cannot sync anymore, or less than every 15-30 minutes. The problem not comming from what you saw. I ended moving my probes cables away from my scope 220V cable - did I get some noises by that way and capacitive coupling?

I now got this, probes cables being away from any mains cables. With probes on their respective rail. I'll now do some more tests, like with one probe at GND.

After that all, I will at least conclude the D50s works not that bad, even feed by only very poor 4.5V quality.

 

[b4nt]

@pma Got again one big noise. They all seem random (in level and time). My probe cables now being away from any mains cable. Now checking with one probe at GND, to see.

 

[b4nt]

@pma @solderdude that is probe 1 to the setup. Probe 2 laying close, but shortened to ground. How would you tweak/fix that? PS: If it is EM in my home, I'm still alive.

 

[Raindog123]

@b4nt Your probes’ loop is probably picking up RF noise. If you reposition the probes - keep them together vs open up the loop - does it change the amplitude of the bursts you‘re seeing? (Ie, if it is external, RF induced noise, does it level change if you change the “antenna” geometry?)

 

[alek19000]

@b4nt Use twisted paired shielded cable.

 

[b4nt]

@b4nt Your probes’ loop is probably picking up RF noise. If you reposition the probes - keep them together vs open up the loop - does it change the amplitude of the bursts you‘re seeing? (Ie, if it is external, RF induced noise, does it level change if you change the “antenna” geometry?)

I just changed my probes for two vintage Tektronix x10, to see. Meanwhile, my D50s plays very nice.

They dont catch the same:

@b4nt Use twisted paired shielded cable.

I won't twist my Tek probes

 

[b4nt]

@b4nt(Ie, if it is external, RF induced noise, does it level change if you change the “antenna” geometry?)

+ @pma

That is what the Tek probes (x10 100MHz) just catched...

 

[b4nt]

@Raindog123 I get some short bursts every 15 to 45 minutes now. Not easy to tweak my setup/measurements so.

But I'm almost sure there is something going on here (not impacting the audio). The Teks, bw limited:

 

[Raindog123]

@Raindog123 I get some short bursts every 15 to 45 minutes now. Not easy to tweak my setup/measurements so.

Remind us, what are you trying to accomplish?

Maybe it is “as good as it gets” - you do see some infrequent noise on your scope. That most definitely is of RF nature - eg, some WiFi/Bluetooth chatter, some processor activity leakage, or such - and I am pretty sure is weak and is of no any danger to humans… And this noise is inaudible - does not seem to affect your hifi in any way, so you should be cool..?

 

[b4nt]

Remind us, what are you trying to accomplish? .... so you should be cool..?

After some tweaks, I have no more audio quality issues here. I'm just checking, for fun.

Adding now that my D50s can work very fine with a poor/noisy 5V power supply
Maybe RF noise, or I get some noise comming in via EMI filters, but this has no effects on my audio

 

[Chrise36]

After some tweaks, I have no more audio quality issues here. I'm just checking, for fun.

Adding now that my D50s can work very fine with a poor/noisy 5V power supply
Maybe RF noise, or I get some noise comming in via EMI filters, but this has no effects on my audio

If you want to see something just put your phone near the D50S you will not only measure but you will probably hear it from the speakers. Btw can you measure any dc coupled amplifier?

 

[b4nt]

@b4nt Your probes’ loop is probably picking up RF noise. If you reposition the probes - keep them together vs open up the loop - does it change the amplitude of the bursts you‘re seeing? (Ie, if it is external, RF induced noise, does it level change if you change the “antenna” geometry?)

I think I should build a different probe, following that model:

 

[pma]

Cable shield capacitive current will remain an issue.

 

[HD MOVIE SOURCE]

Great post and video. Now the big question is... Does PS Audios Power Regenerators, the P15 or P20 PowerPlant have any impact? Because I believe that produces the absolute cleanest power you can get.

You could say, where do we stop, but if the PS Audio P20 Powerplant has no effect then I'm 100% on-board with this idea that they have zero effect.

I'm not in the disbelief camp, it's been proven that this has no effect. But, I'd like to see if 100% regenerated power, completely clean power has zero effect of what we hear.

 

[Helicopter]

Great post and video. Now the big question is... Does PS Audios Power Regenerators, the P15 or P20 PowerPlant have any impact? Because I believe that produces the absolute cleanest power you can get.

You could say, where do we stop, but if the PS Audio P20 Powerplant has no effect then I'm 100% on-board with this idea that they have zero effect.

I'm not in the disbelief camp, it's been proven that this has no effect. But, I'd like to see if 100% regenerated power, completely clean power has zero effect of what we hear.

This one produces clean power. What Amir has demonstrated is that clean power is not actually beneficial for the audio devices running on the clean power. Why would it matter that another power regenerator also makes clean power?