Hum where's it coming frum?

awsmone · Apr 19, 2014

Hi all

I have an annoy problem and need to hot house ideas where the interference is coming from

I use step up transformers in my system

All day quiet as a tomb, then come evening a buzzing starts

Eliminated equipment in room so something I think on same circuit as my hifi room elsewhere in house

Any thoughts?

mep · Apr 19, 2014

What turns on in your house in the evening? If it's not there in the day time and shows up in the evening, something is switching on in the evening.

Steve Williams · Apr 19, 2014

mep said:
What turns on in your house in the evening? If it's not there in the day time and shows up in the evening, something is switching on in the evening.

Not only his house but everyone on the grid

awsmone · Apr 19, 2014

Funny you mention that at my previous house it was worse till the next door neighbour moved out and it stopped lol

I am long way from neighbours now as on 1/2 acre block

Could it be fridge at night some sort of eco mode when power is cheap?

mep · Apr 19, 2014

Steve Williams said:
Not only his house but everyone on the grid

Steve, the funny thing is that the grid usually gets more quiet at night. How many people have remarked over the years that their system sounds best at night?

awsmone · Apr 19, 2014

Could be hot water systems that often reheat at night, but mine is gas will check this

Steve Williams · Apr 19, 2014

Not sure if this helps

http://www.whatsbestforum.com/showt...r-analog-chain&p=236466&viewfull=1#post236466

ddk · Apr 19, 2014

awsmone said:
Hi all

I have an annoy problem and need to hot house ideas where the interference is coming from

I use step up transformers in my system

All day quiet as a tomb, then come evening a buzzing starts

Eliminated equipment in room so something I think on same circuit as my hifi room elsewhere in house

Any thoughts?

Lights are what come on at nights. Dimmers, transformers for low level halogens, fluorescent lights and ballasts all emit electrical noise.
david

awsmone · Apr 19, 2014

Yes thats a good thought !

Big Dog RJ · Apr 20, 2014

He's based in Canberra.

I have a strong feeling it's Prime Minister Tony Abbot and his parliament members that's causing the hum...

G'day mate,

I'm based in Melbourne, mate of mine had a similar problem. The circuit that was part of the audio system also had a few heaters plugged in along with fans and other cooling appliances. The moment he got a dedicated AC line for his system, the hum disappeared altogether. He just installed a simple 10Amp circuit with circuit breaker for safety and that was more than enough to power the whole system. Some people use dedicated 15amp circuits but not required. I am using a dedicated 10amp circuit myself and all is very quiet regardless of time of day.
Only thing making a noise is the good wifey snoring and thinking of Henry Cavil.

By the way what's it with women and this Henry Cavil guy anyway?

I also have a feeling your step up trannies may be causing some feedback. After installing the dedicated circuit, please have a qualified electrician check the circuit out for any traces. This should sort it out or at least isolated the problem.
Cheers,
RJ

Rufus McDufus · Apr 20, 2014

I've found LED bulbs and dimmable CFLs are bad in particular for noise. I use balanced PSUs and I get random short bursts of hum through the day from the transformers.
My street is quite densely packed with houses and people, and there's a fair bit of light industry too. I don't find my hifi sounds better in the evening though unfortunately ( even with all the lights turned off!).

merrillaudio · Apr 21, 2014

Interesting everything. Here are my findings from developing highly sensitive equipment with 70db gain.

It is true the noise from external equipment causes hum in a system. There is also all sorts of other noise that can come into a system. It is up to the system to reject the noise.
1. Ground hum is the result of just bad grounding in the system. If that is done correctly that ground hum will go away. The star has to be correct also. If the star configuration generates different grounds for different circuits, i.e. the star is too far or not the basis of the circuit, then external influences are very strong.
2. Power supply has to remove noise, hum etc and reduce not just the ripple but also the spurious noise.
3. The case has to protect RFI/EMI from entering ( and some cases from exiting).

You cannot change the above but you may be able to identify if one component is worse that the other but using ground lifters on one component at a time. Once identified, then you will have to look for other solutions, perhaps differential circuits etc.

Disclaimer. I know nothing! (Colonel Shultz, hogans heroes)

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Hum where's it coming frum?

awsmone

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mep

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Steve Williams

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awsmone

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mep

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