Mains noise and instability

[yigitboy]

Excuse me for my English first.
I listen to my headphone system at work. And i hear differences between working hours and nights. There are a lot of High current industrial machines around. My amplifier is graham slee solo ultra diamond with linear ps, and a topping d30 with smps. I cant modify mains wires or change the electricity system because i Am not the owner of the builsing. Is it a placebo or can i do anything to stabilize my electricity. For example will a linear ps make d30 better?

 

[restorer-john]

Some gear is more sensitive to mains borne noise than others. Often at night, when things are generally quieter, you can hear all sorts of aberrations on the mains supply as heavy industry takes advantage of the lower cost electricity.

We have ripple control on our electricity grid (for off peak hot water systems) and I sometimes hear those annoying low level noises if things are really quiet.

A line interactive UPS would be a reasonable low cost way to stabilize fluctuating power.

 

[amirm]

I would bet on it being placebo unless you are literally hearing buzz/pop/static.

 

[yigitboy]

I would bet on it being placebo unless you are literally hearing buzz/pop/static.

When the 300Ton Pres machine hits the mold i hear some buzz or pop.
Do you mean electricity instabilities do not affect sound quality?

 

[March Audio]

Any electronics with regulated power supplies shouldnt have any significant problems. The only component which often does not have a regulated PSU is a power amplifier (or PA section of an integrated).

Its a very small picture but it looks like a typical voltage regulator at the close end, single rail supply.

Of course its still possible that some extreme noise spikes get through, especially as being single ended its possible that the signal shield is connected to mains earth.

Remember your hearing also changes through the day.

 

[amirm]

When the 300Ton Pres machine hits the mold i hear some buzz or pop.
Do you mean electricity instabilities do not affect sound quality?

Correct on the second one. On first, then that is an issue but only during that time. It will be a difficult thing to fix.

 

[solderdude]

It is a well known fact that people start to hear 'better' in the evening.
This is of physiological nature.

Whether or not equipment is affected by mains noise is highly dependent on:
1: Immunity of the equipment itself (varies from component to component)
2: The cables/connections between them (screening etc)
3: efficiency of the used headphones
4: the severity and type of distortion on the mains grid.
5: the used power supplies
6: wire routing.
These factors make it hard to 'diagnose' correctly based on little info.

Try to use battery fed equipment or use a regenerative power supply (beware not all UPS do this, especially the cheaper ones) if you want to make sure. Charge the UPS during hours you are absent and use when needed. I recommend to disconnect the mains plug of said rgenerative mains supply.

Chances are mains filters won't do anything about the hum heard from the press.

 

[yigitboy]

It is a well known fact that people start to hear 'better' in the evening.
This is of physiological nature.

Whether or not equipment is affected by mains noise is highly dependent on:
1: Immunity of the equipment itself (varies from component to component)
2: The cables/connections between them (screening etc)
3: efficiency of the used headphones
4: the severity and type of distortion on the mains grid.
5: the used power supplies
6: wire routing.
These factors make it hard to 'diagnose' correctly based on little info.

Try to use battery fed equipment or use a regenerative power supply (beware not all UPS do this, especially the cheaper ones) if you want to make sure. Charge the UPS during hours you are absent and use when needed. I recommend to disconnect the mains plug of said rgenerative mains supply.

Chances are mains filters won't do anything about the hum heard from the press.

Is not a cheap ups already a battery. A headphone amplifier does not use much current. Shouldn't it give enough current to the amp and dac?

 

[March Audio]

Is not a cheap ups already a battery. A headphone amplifier does not use much current. Shouldn't it give enough current to the amp and dac?

Be very wary of cheap Ups for this purpose. They may not have a proper sine wave inverter. If not it will probably create a lot of noise.

 

[yigitboy]

Ok. Does a linear power supply replaces the need for a filtering

 

[solderdude]

The issue with most UPS is that MOST of them simply connect the mains input to the mains output as long as the input voltage falls within set parameters. As soon as the mains voltage drops away the internal generator is switched on/in and only then it uses its battery.
The rest of the time it is just patching though mains.

As long as it is a so called online UPS it will have a constant output voltage that is always generated (and thus also constant) while charging and when disconnected from mains. The more expensive ones usually have a better 'sinewave output' while the cheaper ones often have a less sinewave alike output voltage.
These online UPS are also called double conversion (mains to battery and battery to mains) or regenerative UPS.

In your case going battery operated may be the cheapest and best option.

 

[solderdude]

Ok. Does a linear power supply replaces the need for a filtering

A linear power supply is more sensitive for power dips than a switcher. It all depends on how big the dip is, how much current is drawn and how much 'headroom' the regulator has.

Mains filters do not help with voltage dips or asymmetric power dips (DC alike issues). These only help with fast transients. A decent common mode filter and some voltage arrestors and a wide range (SMPS) should be enough.
Your issues may not be mains voltage related but could also be common mode current related.

 

[yigitboy]

I will try ups while it is disconnected to mains. I understand the best way can be a battery feeding. What will be the cost

 

[solderdude]

The costs could be a decent DAP with 8-10 hours of playing time that can drive most headphones.
FiiO is a cheap option.

The other option is to use an UPS disconnected from mains but you should keep in mind that most of the smaller ones have pretty 'dirty' mains output voltages because their primary goal is to feed the SMPS of a PC in times of power outage for just enough time for it to shut down gracefully.

 

[yigitboy]

The costs could be a decent DAP with 8-10 hours of playing time that can drive most headphones.
FiiO is a cheap option.

The other option is to use an UPS disconnected from mains but you should keep in mind that most of the smaller ones have pretty 'dirty' mains output voltages because their primary goal is to feed the SMPS of a PC in times of power outage for just enough time for it to shut down gracefully.

You are telling to me to get rid of 800pound priced amplifier and use a Dap? It is not easy to feed an hp like sennheiser hd6xx with a Dap.

 

[solderdude]

You asked for solutions and gave you 2 possible solutions.

My FiiO X3 (original) has no trouble driving my HD650.
There are other DAPs as well that have no problem driving 300 Ohm in the same price class as your amp.
Cheap DAP's, phones, tablets and laptops will not be able to.
In any case you'll be free of mains and are even portable.

Another option is using a phone or tablet + decent portable amp.

Try it with an UPS first.

 

[yigitboy]

I thought daps can't feed senn hd6xx, ok i will search for more

 

[yigitboy]

Dac or amp? Which one is affected more from the problems

 

[jsrtheta]

Excuse me for my English first.
I listen to my headphone system at work. And i hear differences between working hours and nights. There are a lot of High current industrial machines around. My amplifier is graham slee solo ultra diamond with linear ps, and a topping d30 with smps. I cant modify mains wires or change the electricity system because i Am not the owner of the builsing. Is it a placebo or can i do anything to stabilize my electricity. For example will a linear ps make d30 better?

What is the ambient sound level during the day? At night?

 

[yigitboy]

10-15db lower at night