Resolving Hum with Battery Back-up (EcoFlow) vs Power Conditioners: success vs failure

@uberk I thoroughly enjoyed and most importantly understood clearly the message your post was intending to make. You weren’t trying to discredit other’s audio choices or beliefs but unfortunately the typical “sit in front of my computer” trolls come out and put words in the author’s mouth through a defensive and personal misunderstanding, either intentional or unintentional, of what your message true intent was.

Your underlying issue and ultimate resolve was the same as mine. A design flaw by the manufacturer where in some instances and systems rears its ugly head. No cable or over embellished marketing claims by manufacturers or DC offset correction could possibly solve your issue. My situation was just like yours, the manufacturer tried to be helpful but ultimately blamed it on the power in my brand new custom designed 7 figure home. In the end it was their product design or lack thereof that was the root cause.

I encourage you to please post my exact response yesterday morning if you still have it, I was interested to see if there were any comments but the post was deleted along with my contribution.

It would be a much better environment here if contributors would seek what the essence of your post is about prior to slagging or twisting your intent in an unproductive and almost slanderous way.

I hope some of those posting learned something from this and once again thank you for sharing a similar journey as mine. It wasn’t fun but was satisfying to get it resolved. I believe my system has the quietest and blackest background compared to anything I’ve ever heard. No one could object if they sat in my room and listened.

One thing I didn’t mention was the response I got from the manufacturer (their very well known in the audiophile world face of the company) given these were brand new amplifiers and after 000’s of dollars solving the problem. I asked for a return and refund (they were new) for his malfunctioning product (in my system) back and his only offer was to advise that, “ people often call me for a good deal on used or demo product so I’ll give them your name”. Crickets… is anyone interested in 2, 250 or 300 foot 10 gauge custom made extension cords…

@gnaudio  unfortunately, I could not copy it in time - I had grabbed only the end of it. The entire post was brilliant, thanks for sharing it.

The whole thing was a learning - and I included learnings in the new OP.

As for the manufacturer, and what I quoted. I had the same experience - when I went for additional help the response was cricket. 

You went WAY beyond actually finding their product defect - and still crickets.

In the end .. we are on our own and if partnered with a good dealer, have some support.

@uberk agreed. There are some great contributors here and some I’ve learned a lot from and trust their thoughts, judgements and overall assistance.

Others, well, I’ll just leave it at that and happy listening to all!!

@carlsbad2 Disagree. I did not draw fast conclusions in my first post. It was the result of 4 months of pain. My error was that:

1. I did not provide the majority of the research and testing I did

2. I also got into a couple back and forth with toxic posters. My opening also expressed a bit too much frustration at one vendor’s support

3. Did not address the broader power conditioner market issue (below). But I did (in the above) show just how contentious this is via testing posts

The above is a reiteration of the conclusions from the first post expanding on the testing as there were many questions on testing - which can help others.

Further, I added additional research that I had done (posts I read that are relevant).

I added no additional testing.

To your point, there is a difference between power conditioners and regenerators - and the industry widely uses the term.

The Niagara 5000 is not cheap, it is close in price to a midrange but it is not a regenerator.

I did not test the PS Audio regen.

As for credentials. My background - I started as a computer engineer and the first thing you learn is flow charts and debugging.  I have spent my entire career in technology. 

To me, this was one debugging exercise. As I have done for decades with teams of people.

The above, which has additional info, is one big debugging flowchart. 

And I expanded the conclusion beyond hum to all audio power. 

There is no magic bullet. 

+1 carlsbad2.  Being an engineer I do not usually get along with physicists.  But you seem to be well grounded (pun intended) with a farm upbringing.  I remember those inverters in the 70s.  Power tools worked with them but they would get noticeably hot after a bit, as I recall.  I didn’t know they produced a square wave.  That is harmonic distortion to the max- when a sine wave is the intended output.

There was a post here moments ago that got redacted for some reason about harmonic distortion in the power lines.  I thought that was a good point.  I can occasionally hear a quiet hum emanating from my Niagara 5000.  The owners manual states this is normal indicating some distortion on the power coming into the house.  I never hear noise through my speakers.   I have the amps on one dedicated circuit plugged directly into the wall and the front end on another dedicated circuit plugged into the Niagara 5000.  I made sure the two white wires were adjacent on the bus bar in the breaker box and the two ground wires adjacent on their bus bar.  Both dedicated lines are the same length but I doubt that means anything.  But I wanted to minimize any potential ground loop using two different circuits.  My house is 24 years old so by rights I should replace the ground rod outside.  But for now it is not broken so I am not motivated to fix it.

I have never heard nor seen a PSA regenerator in person.  I have shied away from such devices because I was uncertain just how well they reproduce power as compared to the power company.  Years ago our power in the US was well regulated and clean.  These days it does not always seem to be the case.  My experience has been that these solar farms going up around the country are electrically noisy and raised havoc on our test equipment at work some years back.  We had to improve our grounding at the plant just to get clean enough signals for our products to pass final test.  Mostly 60 Hz noise was the problem.

I also suspect that audio quality regenerators are much more costly than general home backup power systems in order to not degrade the sound- or so we are lead to believe.  Some basic waveform scope traces and FFT analysis of each version, basic backup power vs. audio grade would show any difference.  Caveat Emptor.  No, I do not possess the test equipment to do such a comparison even though I have the technical ability. 

@carlsbad2 this is not meant to be something I wish to cause a battle over but I think the biggest problem in threads like this is how you started the message above. That was very judgemental and subjective. I didn’t take @uberk s post that way at all. @uberk and I have never met, never commented in the same posts before as I usually don’t post here but I struggle with you stating how he’s learned not to jump to conclusions. It’s not yours or anyone’s place to say that. It was his post, not yours, if you don’t like the content move on. Be the solution, not the problem.

I had a hum (very noticeable) on a new system – only on the tube part 

There was NO hum using SS amp.  So it's either the tubes or that particular tube amp that is the problem. I would simply NIX the tubes. Easy fix. There are plenty of excellent SS choices that don't require rebuilding an electrical grid in order to listen to music. I could never recommend anyone buy a device that required such treatment.

The OP has means, motivation and ability.  I would not judge him for his choices but rather work to understand how he chose the path he did.  The first round of this thread lack much pertinent information that left most of us guessing.  

I too, wonder if set of replacement tubes would resolve the hum.  And it is still not clear to me if the hum is in just one channel.  If the hum is heard in both channels then I get the path the OP took  If the hum is heard in just one channel, then further clarification is required.

Cleaning the power won’t get rid of the hum. Changing grounding will.

Agreed.  But the OP already stated that his amp has hum even with no interconnects attached.  So no ground loop since the only connections to the amp are power and the speakers.

Unless, the problem is in the speaker...  But how could that be?

@uberk, when you disconnected the amp from the preamp and still heard hum, did you disconnect both inputs from the amp?

@uberk 
Whew! What an ordeal. Good to hear…know that you solved the hum problem.  Maybe some components more sensitive than others to poor grid power quality. 

@carlsbad2 as I said, I agree that there is a difference between two classes of power conditioners and regenerators. I do not test the regens because I did not believe it would make a difference after all my reading. And I found a solution.

With regards to what I tested, I still think it is snake oil that does not do what the marketing claims (as outlined in the above)

And @cleeds no. It is NOT a false claim.

It is an opinion. You may disagree - but it is not false.

It is MY view and my experience, and testing holds to the view as the ones did not do what it said it would.

As it is MY view, others are allowed to have a view that it worked well for them.

To avoid toxicity in this thread - there needs to be tolerance for people who passionately hold different views.

My Niagara 5000 is a doorstop. Others will not have the same experience. We can have different experiences and both be valid.

Because the use cases, equipment combinations and experiences are so wildly different.

uberk

It is NOT a false claim. It is an opinion. You may disagree - but it is not false. It is MY view and my experience ...

It is silly to claim that power conditioners are snake oil. It can be shown empirically and through measurements that they produce results even if they didn't work for you. So yes, you can repeat that it is your special view that they are snake oil, but it is so easily disproved. And that is part of the trouble you ran into in your last thread and again in this one.

I was using a Furman PF15 elite power conditioner on my stereo system; but not with the amp. Tried it with the amp but I could hear degradation, ie. constraint. I was using a Pass Labs X350 back when I got that Power Conditioner. I used the Furman for a few years. Changed amps along the way and then brought home the Niagara 5000 with a Hurricane power cord from my local Audio Store (180 miles away local) for an audition. I kept the Niagara. For me it was quite the improvement in sound. It was a lot of money but once I heard my system with the Niagara I didn’t want to go back to living without it.

So I put the Furman power conditioner on my Home Theater setup. The improvement of the picture on the TV blew me away. Colors were brighter/richer and the picture was sharper- not a subtle change at all. I was using an old MC surge protector before the Furman. So these experiences have made me a believer in power conditioners. Purely subjective; but for me far from snake oil. I was using a Sony XBR LED TV at the time. But most people (friends and family) think I’m crazy to suggest they buy a $900 power conditioner for their $1200 TV. Maybe I am crazy to be so critically discerning.

Carlsbad2 is it possible to bypass the ground at the breaker box and run a big earthen spike into the earth and wrap copper wire around much like a lightning  rod then run it to you ground on outlet or is that just considered " sparky" . How else to change the ground. Few electricians work in audio electrics hard to find one who knows in our area.

@gdaddy1  There was NO hum using SS amp.  So it's either the tubes or that particular tube amp that is the problem. I would simply NIX the tubes. Easy fix. 

Fair point. Thought about it for sure. But 1) I already have them 2) resell is a paid 3) They are 60KG each ... so reselling is literally a pain and 4) solved it 99.9%.

They sound great now.

@cleeds It is silly to claim that power conditioners are snake oil. It can be shown empirically and through measurements that they produce results even if they didn't work for you. So yes, you can repeat that it is your special view that they are snake oil, but it is so easily disproved. And that is part of the trouble you ran into in your last thread and again in this one.

The trouble I ran into is people not allowing me to have my opinion - as I am allowing them to have theirs - and expressing frustration. I will not do that again.

For your posts - PLEASE avoid toxic statements.

Comments like "it is silly" is condescending and devaluating and frankly there is no room in this thread for that.

You are welcome to say you disagree. 

That is the whole point of this forum - which apparently some people have forgotten as they desperately need to be right - versus sharing they do not agree.

But it is my opinion and experience. Furthermore, when I read about the PS Audio P20 it is my opinion (and from speaking to 2 dealers, theirs also) that I should not buy it.

Therefore, I think my Niagara 5000 and the ones I tested are snake oil because they did not meet the marketing that was put out.

Feel free to disagree, in a cordial way.

@uberk I agree the filter style conditioners, including some name brands, don’t do anything useful. But your post sounded like just because they didn’t solve your problem, you called them snake oil. This will always result in attacks on your integrity if not your mother’s also, especially from those who have invested $5k or more in such an item and feel the need to defend their investment. So the key is to choose your wording not of offend people if you don’t want long argumentative threads. I know because I tend to be blunt and matter of fact and I’ve offended my share.

@carlsbad2 fairly stated and my "too blunt" style in the original where I shared my (significant) frustration - indeed - was wrongly worded. Hence this re-word.

As for learning, that is the essence of life - and would be struck down by lightning if I said I was not guilty of being too blunt and offending others at times.

That being said, I intend on keeping this thread cordial as it is a good topic - and I believe that reading through it can help others.

If nothing else, they get a good synopsis of things "to try" ... which I had to assemble from posts and articles far and wide.

As for this issue .. it is 99.95% resolved so past the hump.

The last thing you want to do is violate the NEC.  The National Electrical Code is in place for our safety.  You can add additional ground rods daisy chained together or replace an old ground rod. You might be allowed to add a secondary ground to your stereo system but it cannot defeat the main grounding.  Check your local codes.  Like ground boxes, a secondary ground might impact some systems depending on circumstances- like maybe if you live near a radio station.  Refer to the NEC and your local codes before making any changes.  Grounding will not affect THD in the power coming into the house.

Can safety ground affect the sound of a stereo system?  I have no idea- unless a component has some strange grounding system that is using earth ground perhaps.  Safety ground and Neutral should check as 0 Volts at an outlet.  Remember that in the US you have two 120 VAC legs and one neutral leg that completes the circuit.  The earth ground is tied to the neutral leg as a safety at the breaker box.  But an electrical device with a three prong plug should not have the neutral side and the safety ground tied together.  A lot of information about grounding is available in the codes and in white papers.  It is not a simple topic as one might think.

Fun story:  Back in the 1960s my Grandfather had a B&W TV at his lake cabin.  Back then everything used a two prong plug.  My brother and I found that if we were barefoot on the concrete floor and touched the metal frame of the TV we would get zapped.  Not a tickle, it was a hearty jolt.  

@uberk agreed. There are some great contributors here and some I’ve learned a lot from and trust their thoughts, judgements and overall assistance.

Others, well, I’ll just leave it at that and happy listening to all!!

@gnaudio  .. any chance we can cajole you into re-creating what was the best post in the entire discussion on your journey? 

I am SO SORRY that I did not copy it before the thread went down.

It was brilliantly written and frankly, mind-blowing to read. 

If you are having a morning coffee and feel inspired .. I for one would love to re-read it. 

I was using a Furman PF15 elite power conditioner on my stereo system; but not with the amp. Tried it with the amp but I could hear degradation, ie. constraint. I was using a Pass Labs X350 back when I got that Power Conditioner. I used the Furman for a few years. Changed amps along the way and then brought home the Niagara 5000 with a Hurricane power cord from my local Audio Store (180 miles away local) for an audition. I kept the Niagara. For me it was quite the improvement in sound. It was a lot of money but once I heard my system with the Niagara I didn’t want to go back to living without it.

So I put the Furman power conditioner on my Home Theater setup. The improvement of the picture on the TV blew me away. Colors were brighter/richer and the picture was sharper- not a subtle change at all. I was using an old MC surge protector before the Furman. So these experiences have made me a believer in power conditioners. Purely subjective; but for me far from snake oil. I was using a Sony XBR LED TV at the time. But most people (friends and family) think I’m crazy to suggest they buy a $900 power conditioner for their $1200 TV. Maybe I am crazy to be so critically discerning.

Thanks for sharing @tonywinga .. we have the same Niagara 5000 and Tornado cable (I think that is one below yours). To your point on running the amp, that is what I put in the OP - everyone says "do not put it into a power conditioner", plug it right into the wall for the best sound.

I have a Samsung 98" QLED - and as I was so focused on the "hum" and amp sound resolution via the Niagara 5000, perhaps it is worth doing testing against that.

@uberk, when you disconnected the amp from the preamp and still heard hum, did you disconnect both inputs from the amp?

@tonywinga .. yes I ran testing with only the amp, speaker cables and speakers connected. No interconnects to any pre-amps. This eliminated the pre-amps as a source of the noise.

Whew! What an ordeal. Good to hear…know that you solved the hum problem.  Maybe some components more sensitive than others to poor grid power quality.

In the end, that is my conclusion @kennyc 

If you read the article from Steve Huff on his 2 year journey or if I can convince @gnaudio to repost his insane journey which makes mine look like a walk in the party with his $250K of equipment, external engineers and electrical companies ... the power problem is not for the faint of heart if it pops up.

Bet there are lots of people living with it .. as they just accept it.

I’d love to get one of the consumer battery/inverters and put it upstream of my P10 an see what the incoming looks like. I’m just not going to buy one and return it to Costco. that drives up prices for everyone.

@carlsbad2 I would encourage you to try it, because you may buy it and keep it. In the end, that is what they are banking on. But I would wait until they carry the Ultra (the new batteries are safer, and much lower heat, so fan noise is low).

As for driving up costs ... Costco is banking on you keeping it and if you walk in there and buy this, they also know that you will leave with a basket full of other stuff.

Just ask all the people who went in to buy a brick of cheese and are leaving with a trampoline.

Plus, I would be VERY curious to hear your outcome - as would others.

I bought the Costco Ecoflow Ultra Package with Electrical Panel. Will put my audio on it as a priority circuit. We get hurricanes here so it will be able to serve more than 1 purpose. It's a backup UPS too.

I remember Ricevs singing the praises of systems he heard with inverter/battery power when we discussed modding an amp for me a while back.

Thank you for this thread.

uberk

... I think my Niagara 5000 and the ones I tested are snake oil ...

Just because these products weren't effective for you does not mean that they are "snake oil." In particular, Audioquest 5000 has multiple features and produces demonstrable, repeatable results. It's not a fraudulent product, which is what "snake oil" suggests.

I understand that, for whatever reasons, the power conditioners you tried didn't give you the results you sought. It clearly was frustrating but I'm glad you found a workaround. I've also suffered problems with hum - it's not uncommon in biamplified systems - but took an entirely different approach.

So let me see if I can boil this down. While I’m glad you found a solution, and I believe you when you say you found a solution, your own description of the problem seems to fail to recognize the original issue that led you to a very expensive path.

Starting state: You have an amp which hums in your house.

Diagnostic step: Remove all inputs.

Results: Hum

OK, this point we’ve eliminated upstream components and the possibility they induce a ground loop.

Two possible conclusions:

A. You have a bad amp

B. You have bad power somehow

Now we must take a step to discriminate between the two.

Diagnostic steps implied by the above and maybe never taken:

1. Move amplifier to different leg, or building or independent power system

2. Shut down all other circuits and powered devices in home.

If the hum stops with either of these two states it conclusively proves you have bad power. End of story.

================================================

By the power of reduction you have essentially proved #1, above but refuse to believe you have bad power. Somehow you’ve come to the conclusion instead that it’s not bad power and not the amp, but that you need a power conditioner to fix your not-bad power problem.

Then you take the radical leap out of logic to blame most power conditioners for being ineffective for your problem.

Your original post, and this one seem to say, again, "I bought a bunch of things which were never designed to fix my problem, and now I know they don’t work."

So, sure, glad you fixed your problem but your thesis is flawed, and your refusal to consider that you have a power problem, despite your own work PROVING you have a power problem is just funny as hell.

+1 erik and leads to the band aid that the OP used, satisfied that the hum gone, using the "that’s good enough, why do you care solution".

@carlsbad2 interesting graph, thanks for posting. Guessing that flat top is the bogeyman for a lot equipment. Question, how does that graph look on Sunday night at 10:30? Does it ever clean up?

Now, getting out of the technical, and trying to assess where the OP’s logic goes awry it is in the refusal to believe he made a mistake very early on:

"I have a power problem and therefore a very expensive power conditioner should fix it no matter what kind of power problem I'm having."

If you refuse to believe this assumption was incorrect, then you must blame the devices you purchased for being "flawed" and everything else is just running around in circles so you don’t have to admit an early mistake made by an inexperienced person working out of their skill set. Your posts are a desire for validation that you were not wrong, the products are at fault. Good luck with that.

The moment you say "I was led astray by my own lack of knowledge, and salespeople" then the rest of the conversation ceases to be needed.

So let me see if I can boil this down. While I’m glad you found a solution, and I believe you when you say you found a solution, your own description of the problem seems to fail to recognize the original issue that led you to a very expensive path.

Starting state: You have an amp which hums in your house.

Diagnostic step: Remove all inputs.

Results: Hum

OK, this point we’ve eliminated upstream components and the possibility they induce a ground loop.

Two possible conclusions: 

A. You have a bad amp

B. You have bad power somehow

Now we must take a step to discriminate between the two.

Diagnostic steps implied by the above and maybe never taken: 

1. Move amplifier to different leg, or building or independent power system

2. Shut down all other circuits and powered devices in home.

If the hum stops with either of these two states it conclusively proves you have bad power. End of story.

================================================

By the power of reduction you have essentially proved #1, above but refuse to believe you have bad power. Somehow you’ve come to the conclusion instead that it’s not bad power and not the amp, but that you need a power conditioner to fix your not-bad power problem.

Then you take the radical leap out of logic to blame most power conditioners for being ineffective for your problem.

Your original post, and this one seem to say, again, "I bought a bunch of things which were never designed to fix my problem, and now I know they don’t work."

So, sure, glad you fixed your problem but your thesis is flawed, and your refusal to consider that you have a power problem, despite your own work PROVING you have a power problem is just funny as hell.

Welcome back @erik_squires. As you will see in the OP, I have gone through extensive diagnostics and steps to troubleshoot.

I do not "refuse" to consider that there is a power issue, in fact there is something wrong with the power. But it is not ground - that has been tested. The reports came back fine.

If you refuse to believe this assumption was incorrect, then you must blame the devices you purchased for being "flawed" and everything else is just running around in circles so you don't have to admit an early mistake made by an inexperienced person working out of their skill set. 

I disagree. The power conditioners, make claims (outlined clearly in the OP) and they do not live up to those claims. They are specifically there to resolve power issues. (Please read the quoted text from the power conditioners).

If they are not there to fix problems - that they claim to fix - what are they for?

The moment you say "I was led astray by my own lack of knowledge, and salespeople" then the rest of the conversation ceases to be needed.

Please refrain from quoting when I did not say that. I spent considerable time researching it.

Diagnostic steps implied by the above and maybe never taken: 

1. Move amplifier to different leg, or building or independent power system

2. Shut down all other circuits and powered devices in home.

If the hum stops with either of these two states it conclusively proves you have bad power. End of story.

As I put above, in this regard, you are just wrong. You are telling me what I did not do - when in fact I did. Please read the OP before wrongly stating what was and what was not done.

1. Move amp to different leg. See point #2

2.  Shut down all circuit. See point #2. That is how I eliminated grounding loop.

Two possible conclusions: 

A. You have a bad amp

B. You have bad power somehow

A. You have a bad amp. Please see point #7

B. That is what is clearly outline in the OP above. 

Are you reading the OP before posting? Please take the time to read the post before posting items that have been covered.

Last.

your refusal to consider that you have a power problem, despite your own work PROVING you have a power problem is just funny as hell.

I know there is a power problem. That is what the whole point of this OP is. If there was not a power problem - why would I post.

I just reject replacing all the wiring as the ground is good, and it is on a dedicated line, and in the end, I found a solution. 

Further pursuits is in fact - margin gains.

Please take the time to read what was done before posting what has been covered.

Thanks - we want to keep this cordial and non-toxic.

A thread where people can agree to disagree - as I do with "some" of your points.

+1 erik and leads to the band aid that the OP used, satisfied that the hum gone, using the "that’s good enough, why do you care solution".

@dill  

I disagree. The above proves it is not DC, not grounding, not grounding loop. Among other things.

I would encourage you to read Steve Huff's articles.

He did what @erik_squires suggested and rewired his house (because it is old - mine is not), and he did not have a dedicated 20AMP line (I do) ... and it did nothing.

There is no silver bullet.

What works for one, does not work for another is my conclusion.

So we will agree to disagree.

I just reject replacing all the wiring as the ground is good, and it is on a dedicated line, and in the end, I found a solution. 

I never said you had a wiring issue. You have an unresolved power problem, which could be benign or not.

Just because these products weren’t effective for you does not mean that they are "snake oil." In particular, Audioquest 5000 has multiple features and produces demonstrable, repeatable results. It’s not a fraudulent product, which is what "snake oil" suggests.

@tonywinga clearly outlined how he had great results.

For me, they made claims, I did not get them across multiple products and my reading (Such as the audio science tests) have me at that conclusion.

That being said - as I said in my opening conclusion.

One persons gold, can be another person’s coal. @cleeds

This is an opinion - and others are welcome to have a different opinion.

I get your point, I just do not agree.

 

I just reject replacing all the wiring as the ground is good, and it is on a dedicated line, and in the end, I found a solution.

I never said you had a wiring issue. You have an unresolved power problem, which could be benign or not.

@erik_squires then we will agree.

From my perspective I have gone as far as I can as I will not pursue the power company.

I also might have tubes that are - frankly - too sensitive for the power. But I have spent months resolving this and now its s a case of marginal gains - and for the record as I posted - it is 99.95% resolved. 

I bought the Costco Ecoflow Ultra Package with Electrical Panel. Will put my audio on it as a priority circuit. We get hurricanes here so it will be able to serve more than 1 purpose. It's a backup UPS too.

I remember Ricevs singing the praises of systems he heard with inverter/battery power when we discussed modding an amp for me a while back.

Thank you for this thread.

@dolfan  that is awesome. My experience too.

There are many others over on this thread (which is where I learned about this) who have the same experience living in marginal areas or areas with bad weather.

The added benefit is:

1. Lower power costs (because you can recharge in the evening)

2. Whole home surge protection

3. Battery backup for brownouts or blackouts.

Tesla powerwall, Ecoflow, GoalZero and others are innovating at an incredible pace - really interesting technology. I eliminated all the UPSs on PCs too. 

It is a huge industry that will get better and batter.

@carlsbad2 Thanks for the follow up. Agreed that the Sunday night thing could all be in our heads, but it is such a universal phenomena it is worth looking for both physical and mental causes.

"The hum came from a pair of brand-new MC451s"

- My question would be why?

@carlsbad2 Thanks for the follow up. Agreed that the Sunday night thing could all be in our heads, but it is such a universal phenomena it is worth looking for both physical and mental causes.

To your point @zlone  there is so much written about that - which is another reason why I will have an electrician in to wire up a monster bank of EcoFlows to pull me right off the grid for direct power, with the batteries being recharged by the grid in the evening at a lower cost.

So during the day running it all off the batteries. 

To get more predictable, the surge protection and the lower recharge costs.

Edit to add:  I think the belief that stereo sounds better at night when the power cleans up is really it sounds better when you are relaxed, maybe had a glass of wine, and there is less ambient noise.  I think people underestimate the amout of noise pollution coming into your listening room.  It becomes background and you learn to ignore it.  Power doesn't clean up.  and when you have a power regenerator like mine, it still sounds better at night when I'm relaxed.

@carlsbad2 everything is better with a glass of wine is probably an excellent axiom that I would wager few would dispute.