• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Why none of us audiophiles still cannot completely get rid of the "hum" in this day and age?

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
2,995
Likes
2,308
Unfortunately, most of us, power most of our gear, from mains AC..... and have to bear with/deal with its frequency and harmonics thereof...

With the move to Solar power and batteries, maybe we will start to shift to DC battery based systems - that would indeed eliminate all hum!

(of course then you have all those recordings made on AC powered gear that may well have humm recorded into there "baked in"...)
 

antcollinet

Master Contributor
Joined
Sep 4, 2021
Messages
7,215
Likes
11,971
Location
UK/Cheshire
This (and similar ones) is a nice anecdotal story. Why don’t you rather post a measurement (properly scaled, or in dBV) of noise spectrum at the power amplifier output of your completely connected audio system, in the configuration as you listen to it?
I suspect if a person can't hear any hum the motivation to set up a test system for it might be lacking. :)
 
Last edited:

Geert

Major Contributor
Joined
Mar 20, 2020
Messages
1,912
Likes
3,412
No hum over here. Configuration is a NUC with USB connection to an integrated amp with 103dB S/N, don't see why it should hum as long as you don't create ground loops yourself.

Unfortunately, most of us, power most of our gear, from mains AC..... and have to bear with/deal with its frequency and harmonics thereof...

With the move to Solar power and batteries, maybe we will start to shift to DC battery based systems - that would indeed eliminate all hum!

A decent amplifier power supply filters out mains pollution. See Amir's amplifier reviews.

Solar power systems contain switching inverters to do DC to AC conversion. These are not audiophile grade devices. I see a business opportunity here..
 

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
2,995
Likes
2,308
No hum over here. Configuration is a NUC with USB connection to an integrated amp with 103dB S/N, don't see why it should hum as long as you don't create ground loops yourself.



A decent amplifier power supply filters out mains pollution. See Amir's amplifier reviews.

Solar power systems contain switching inverters to do DC to AC conversion. These are not audiophile grade devices. I see a business opportunity here..
What I was suggesting, is that homes can be built running exclusively on DC - the panels put out DC, the batteries run on DC...

A home off grid system running purely on DC is perfectly viable - and would potentially be excellent for audio.
 

Geert

Major Contributor
Joined
Mar 20, 2020
Messages
1,912
Likes
3,412
What I was suggesting, is that homes can be built running exclusively on DC - the panels put out DC, the batteries run on DC

I see, but (of the shelf) amplifiers still run on AC unless you modify them. Even than you might need to foresee voltage regulation and a DC-DC step-up converter. Might not be worth the effort if you don't have a mains power problem to begin with.
 

notsodeadlizard

Senior Member
Joined
Feb 18, 2023
Messages
403
Likes
361
I'd like to bring to all the audiophiles attention this problem. No matter how expensive and carefully set up your system is, you know the hum is always there given enough volume and no source active. Generally, it's a lot worse than that and we just agree to live with it. We are all such perfectionists, we can spend thousands of dollars for a Dac that can process 768kHz and replace our 384kHz Dac and yet we accept to hear the hum. I learned how electricity is really delivered to our homes from a video of Amir at the age of 50 (and I have an engineering degree) and what is grounding and why it causes the "hum" but even he didn't offer a solution to get rid of it. Is there no solution? If there's, why doesn't anyone do anything about it?

I don't presume any techincal knowledge on the matter so I might be all wrong but I hear the hum. I lived in 3 different continents in the last 30 years and used many different brands of gear. The hum was always there to a varying degree (from only audible if you press your ear to tweeter to always there unless there's music playing supressing it). Let's rebel and force electiricity companies or electronics companies or whoever is causing this to stop it.
There is something very wrong with your system.
This problem has not existed for many decades.
Not only in hi-fi.
In household appliances.
For example, in mini-systems.
Buy a Denon and enjoy the silence with the volume turned up to the maximum.
And in general, just buy a Denon, listen to music and stop torturing yourself.
:)
 

Chrise36

Major Contributor
Joined
Dec 23, 2018
Messages
1,034
Likes
352
This (and similar ones) is a nice anecdotal story. Why don’t you rather post a measurement (properly scaled, or in dBV) of noise spectrum at the power amplifier output of your completely connected audio system, in the configuration as you listen to it?
I have managed to achieve this with various measures in my unbalanced setup but the speakers are low sens (85db). Audibly no noise but measured there would be some.
 

theREALdotnet

Major Contributor
Joined
Mar 11, 2022
Messages
1,176
Likes
1,985
On my system Puccini’s Humming Chorus sounds like John Cage’s 4:33.
 

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
2,995
Likes
2,308
I see, but (of the shelf) amplifiers still run on AC unless you modify them. Even than you might need to foresee voltage regulation and a DC-DC step-up converter. Might not be worth the effort if you don't have a mains power problem to begin with.
Yep it could require a complete DC ecosystem
 

chelgrian

Senior Member
Joined
Jul 27, 2020
Messages
321
Likes
353
The answer is not simple, because the existence, non-existence of audible hum depends not only on individual component design, but also on topology of the complete system, interconnects, grounding, safety class of instruments, single ended or balanced signal links. Simply, if you have more than one class I component in the system, you have potential risk of hum, especially in case of single ended links. You may search in my threads and posts, mains related S/N and HF related interference and intermodulation is my main topic. Use optical fibre for digital and avoid multiple class I components, this is a universal and working advice. Tests of individual isolated components under clinical ideal conditions would not tell you what you need to know.

It's not just end users who blame power companies many studios have extremely expensive equitech boxes of dubious value. I tried to read through


But it's a hard slog due to the nonstandard terminology being used and their probably mistaken belief that they have a one true solution that everyone else is missing.
 

ZolaIII

Major Contributor
Joined
Jul 28, 2019
Messages
3,896
Likes
2,306
Much naive people hire. There never whose more EMI then there is today! Probably because most even don't know basics of radio diffusion and RFI anymore. EMI classification goes wide but we should focus on outended input points and transmission rates along with claimed rejection rate for given frequency for individual components (amp's, OPAMP's and DAC's). How hard is to make factor of rejection rate at low frequency range of 100 dB or more.
How to take measurements in first place and such.
While there whose braketrogh regarding materials that have good broadband rejection rates (including problematic low end narow band one particularly hard to block) and aren't really expensive they are pretty much getting faster in use in pretty much every other electric/electronic industry aspect then in audio. Most of audio systems don't even have a basic shielding. Material is good old graphite in the form of TPE graphite mixture shielding/cage. Hopefully audio industry will follow what others are already implementing instead of promoting abominations and snake oil of all kinds.
Short informative easy to read walk through with video example:
Have nice time and have fun.
 
Last edited:

symphara

Addicted to Fun and Learning
Joined
Jan 24, 2021
Messages
632
Likes
590
Good idea. I’ve just petitioned my electricity company to remove the hum from their mains supply.
We'll send our employee-of-the-month to deal with your cable...

disturbing-edward-scissorhands-moments.jpg
 

ahofer

Major Contributor
Forum Donor
Joined
Jun 3, 2019
Messages
4,886
Likes
8,598
Location
New York City
No hum over here. Configuration is a NUC with USB connection to an integrated amp with 103dB S/N, don't see why it should hum as long as you don't create ground loops yourself.



A decent amplifier power supply filters out mains pollution. See Amir's amplifier reviews.

Solar power systems contain switching inverters to do DC to AC conversion. These are not audiophile grade devices. I see a business opportunity here..
The high end community will decide that old fashioned mains are better. Solar power is dry and harsh sounding.
 

ahofer

Major Contributor
Forum Donor
Joined
Jun 3, 2019
Messages
4,886
Likes
8,598
Location
New York City

JayGilb

Major Contributor
Joined
Jul 22, 2021
Messages
1,336
Likes
2,246
Location
West-Central Wisconsin
I run a stack of vintage Carver pro amps, I'd probably be worried if there was no hum.

Based on the number of hum/ground loop questions we see on ASR and the volume of products being sold to cure these problems, it's obvious that many consumers still suffer from mains hum.
It's been more common since pcs have entered the audio chain due to component switching rates and in some cases, crappy power supplies.
 

fpitas

Master Contributor
Forum Donor
Joined
Jul 7, 2022
Messages
9,885
Likes
14,150
Location
Northern Virginia, USA
No hum here, but everything is run balanced. I guess this is further proof I'm not an audiophile.
 
Top Bottom