View Full Version : Do Switched Mode Power Supplies (SMPS) around the house corrupt Hi fi performance
I keep reading how household SMPSs corrupt the electrical mains and this can influence the SQ of Hi Fi systems.
I have just had a quick count up and my house has over 20 SMPS plugged into the mains most of the day and an untold number inside various bits of kit.
Is this a problem and are there solutions?
Thanks
I would suggest in may ways they can and do have effects on many devices not just audio
Firebottle
19-12-2023, 13:28
That's a tricky one to answer. Or rather there isn't a fit all answer.
Based on experience any audio equipment that includes a SMPS can be improved by replacing with a linear PSU. I have done this on numerous pieces of kit.
However the subjective improvement will depend on the overall 'quality' of the complete hi-fi system.
Whether SMPS's external to the hi-fi system have influence on the SQ depends again on the 'quality' of the audio equipment and if there is adequate separation of mains input and audio circuitry. Plus whether any internal filtering is present.
Disconnection of external SMPS's is the approach to see if SQ is degraded.
Replacing all SMPS's with linear PSU's will of course remove all the noise from SMPS's but could prove very expensive, even if possible with all the variations.
my view is that any interference problem will manifest itself as obvious buzz, hum or hiss, it won't manifest as reduced sound quality.
That will depend on the PSRR of the equipment you use. https://en.wikipedia.org/wiki/Power_supply_rejection_ratio
As long as it's well engineered mains noise will have no effect. If it's not you will get obvious issues, not slightly less focused sound of second violin.
I've yet to see any evidence to the contrary.
my view is that any interference problem will manifest itself as obvious buzz, hum or hiss, it won't manifest as reduced sound quality.
That will depend on the PSRR of the equipment you use. https://en.wikipedia.org/wiki/Power_supply_rejection_ratio
As long as it's well engineered mains noise will have no effect. If it's not you will get obvious issues, not slightly less focused sound of second violin.
I've yet to see any evidence to the contrary.
Forgive me if I misunderstand, but I think you are saying that if you plug an SMPS alongside a bit of hi fi kit in a double mains socket it shouldn’t have any effect on the hi fi device. If this is the case, why the general trend to convert SMPS to linear power supplies?
I could pose the question where is the evidence to show there is no effect on hi fi SQ by SMPSs on the same mains circuit.
Forgive me if I misunderstand, but I think you are saying that if you plug an SMPS alongside a bit of hi fi kit in a double mains socket it shouldn’t have any effect on the hi fi device. If this is the case, why the general trend to convert SMPS to linear power supplies?
power supply in a unit can bleed noise into the audio signal and that will give worse sound quality if there's enough of it. So you could conceivably make a difference with a different power supply to the unit - you can get noisy SMPS and noisy linear supplies.
Properly implemented SMPS power supplies can be quieter than LPS they are not intrinsically bad. And also internal layout can matter so fixing a problem there can help - which might be a side-effect of changing the PS.
But that's not the same as 'noise on the mains' caused by another device plugged in somewhere else. Like a buzz through the speakers when a refrigerator motor kicks on.
Go with the advice given - turn off all SMPS devices in the house, see if you hear better quality sound.
I tried this some years back, made no difference, but I only had 4 devices with SMPS so some may argue that wasn't enough to matter.
I was thinking again about 'dirty' mains and remembered that most exhibitors at hi fi shows are concerned at the poor mains quality caused by hi fi kit in nearby rooms.
Equally turning off SMPSs in my house could only be part of the cure. Every other house on the power feed to our area could be part of the problem.
OK
I have just turned off all the accessible SMPSs in the house (about 20). This includes such things as three Alexas, six phone chargers, iPad chargers, computer anxillaries etc. I doubt any great care has been taken in their design in terms of mains polution.
I stopped at visiting all my neighbours asking them to go dark. :)
There is a marked decrease in what I describe as a slight glare to the sound, making the hi fi more listenable. This is exactly the area I want to improve, is very encouraging, and directs me towards a way to eradicate that mains noise. I forgot to listen out for tansformer hum or random noise in the speakers as I was so please with the improvements to overall SQ
OK
I have just turned off all the accessible SMPSs in the house (about 20). This includes such things as three Alexas, six phone chargers, iPad chargers, computer anxillaries etc. I doubt any great care has been taken in their design in terms of mains polution.
I stopped at visiting all my neighbours asking them to go dark. :)
There is a marked decrease in what I describe as a slight glare to the sound, making the hi fi more listenable. This is exactly the area I want to improve, is very encouraging, and directs me towards a way to eradicate that mains noise. I forgot to listen out for tansformer hum or random noise in the speakers as I was so please with the improvements to overall SQ
Don't forget to switch off your Christmas tree lights - these are extremely noisy on the mains!:)
Don't forget to switch off your Christmas tree lights - these are extremely noisy on the mains!:)
Yep, all Christmas stuff including tree and lights were off :)
While fiddling about I decided to tighten the earth clamp from the meter to the gas pipe.
I loosened it first, squirted it with Deoxit, and retightened. This almost free tweek certainly took away some of the underlying harshness to the Hi Fi.
I keep reading how household SMPSs corrupt the electrical mains and this can influence the SQ of Hi Fi systems.
I have just had a quick count up and my house has over 20 SMPS plugged into the mains most of the day and an untold number inside various bits of kit.
Is this a problem and are there solutions?
Thanks
In my experience, yes.
My previous fridge used to buzz a lot, and there was slightly louder background “mush” from the speakers with it on.
Was gone when I unplugged it. Just put up with it till I got a new fridge! Nowadays my system is powered from a separate hardwired balanced mains setup, noise floor gone.
In my experience - sometimes.
I don't use any aftermarket mains products and my power cables are all the ones you get supplied with the equipment - I have zero noise issues and excellent sound quality.
But it can happen - I know people who have had noise problems with dimmer switches, for example.
They key is to address problems if they exist, rather than taking a blanket position of 'SMPS = bad' or assuming that after-market power products will automatically bring improvements. That's a good way to waste a lot of money.
Pigmy Pony
29-12-2023, 12:17
In my experience, yes.
My previous fridge used to buzz a lot, and there was slightly louder background “mush” from the speakers with it on.
Was gone when I unplugged it. Just put up with it till I got a new fridge! Nowadays my system is powered from a separate hardwired balanced mains setup, noise floor gone.
If it's a problem, I would say Gary's is the best answer - Getting an electrician on the job may well be a lot cheaper than you'd expect, and likely cheaper than some of the fancypants 'solutions' you see advertised.
If it's a problem, I would say Gary's is the best answer - Getting an electrician on the job may well be a lot cheaper than you'd expect, and likely cheaper than some of the fancypants 'solutions' you see advertised.
Good enough to power David Gilmour’s Thames recording Studio, good enough for me! :D
https://www.musicradar.com/news/guitars/in-pictures-david-gilmours-guitars-amps-and-effects-616154
Big improvement after having mine installed.
Had 2 installs actually - the Higher output rating, the lower the Impedance on supplied mains. Big improvement even though didn’t have any issues with how the System was sounding before.
It all came about after a ‘Scottish Mafia’ meet at mine, one of the guys brought a plug-in balanced mains and every one of us was there gobsmacked by the improvement.
Knew I wanted this powering my gear.
It’s the reason I put so much emphasis on quality of power feeding my system, everything comes from that.
Sounded great before, it was just… better… after.
Don’t need to go hardcore hardwired install with these, no need for an electrician.
Can get plug-in balanced mains units with a couple of sockets on them, I’d avoid Russ Andrew’s and go for Airlink if anyone goes down that road.
That was similar to the type my mate brought over.
It’s not really a plug and play solution though, as it needs to be properly electrically protected.
I found Airlink terrific in this regard and will advise.
This type isn’t too costly in the scheme of things and gives great bang for buck IMO.
I did my homework and took safety advice before going down this road, you should too.
Edit: I’d avoid mains “conditioners”,
tried a couple from the Tacima mains block up to a mid priced Isotek, just robbed the sound of the dynamics.
I tried balanced mains - in my set up it reduced the sound quality.
I tried balanced mains - in my set up it reduced the sound quality.
Just goes to show you.
My mains could have been quite bad back in the day when I installed it.
Mains supply to house has been renewed with new copper, new CU etc about 5 years ago.
Though powering straight from the wall recently(powered amps and Dac from wall as a test when I modded them) and sound wasn’t as good.
Would never go back to a system without sorting the mains out now.
Just goes to show you.
My mains could have been quite bad back in the day when I installed it.
Mains supply to house has been renewed with new copper, new CU etc about 5 years ago.
Though powering straight from the wall recently(powered amps and Dac from wall as a test when I modded them) and sound wasn’t as good.
Would never go back to a system without sorting the mains out now.
well like I say my view is that in most cases there is no problem to be fixed. That doesn't mean there's never a problem but it's not universal or even common.
Electrical system in my house was last updated in 1973.
Just goes to show you.
My mains could have been quite bad back in the day when I installed it.
Mains supply to house has been renewed with new copper, new CU etc about 5 years ago.
Though powering straight from the wall recently(powered amps and Dac from wall as a test when I modded them) and sound wasn’t as good.
Would never go back to a system without sorting the mains out now.
100% agree Gary, in fact we had our whole house rewired recently with new CU unit and new sockets, much of the cable was also renewed and all wall switches etc. I did listen to my system previous to new rewire and felt afterwards it sounded better by some margin.
well like I say my view is that in most cases there is no problem to be fixed. That doesn't mean there's never a problem but it's not universal or even common.
Electrical system in my house was last updated in 1973.
Disagree Martin,
can’t speak obviously to your view but, to be fair, I don’t think either of us knows how common bad quality mains (for hifi purposes) could possibly be.
but hey ho. :)
We’re both speaking from our own experience, which is all we can really do.
But how could that last length of cable make a difference? :eek:
Hang on, maybe it ALL does.
100% agree, made a difference at my gaff too.
1973?
Martin, get yer mains sorted Mucker! :ner:
100% agree Gary, in fact we had our whole house rewired recently with new CU unit and new sockets, much of the cable was also renewed and all wall switches etc. I did listen to my system previous to new rewire and felt afterwards it sounded better by some margin.
Pigmy Pony
29-12-2023, 17:05
I misunderstood Gary's earlier post. I thought he was talking about a dedicated mains from the Consumer unit to his rig, and that made sense to me. Simply having the hifi on a separate circuit to to all the other appliances in the house.
Had a quick read up on these balanced mains units, and what little I understood scared me off :doh: I've had electric shocks before, and it's not as much fun as it sounds :(
I misunderstood Gary's earlier post. I thought he was talking about a dedicated mains from the Consumer unit to his rig, and that made sense to me. Simply having the hifi on a separate circuit to to all the other appliances in the house.
Had a quick read up on these balanced mains units, and what little I understood scared me off :doh: I've had electric shocks before, and it's not as much fun as it sounds :(
That is what I have: a separate 32A ring-main consisting of 16 sockets fed by a separate RCBO Consumer Unit connected to the meter via a Henley block.
Does it make a difference? - not that I have noticed, but then I didn’t have mains problems before. I just took the opportunity when the floorboards were lifted to have radiators fitted, to have the new ring installed; thereby reducing the need for trailing cables, distribution strips and other unsightly horrors.
I can't remember off-hand what the source impedance is, but it's about 0.25 Ohm (lower than the usual expected value), and the measured DC offset is < 3mV.
Yeah…
need to do some reading up on them, perhaps not for everyone’s setup.
Used in Studios around the world to eliminate electrical noise, need to pay attention to safety and put things in place.
100% safe if done properly, the plug n play box is the easiest route to entry.
Remember back in the day having a massive Barney with Richard Dunn over mine, unsafe he said.
NVA ended up producing one anyway.
got my ‘hardcore’ install signed off by a Spark, all Primary and Secondary RCBO safety trips put in place.
Not for everyone obvs, but they work.
I misunderstood Gary's earlier post. I thought he was talking about a dedicated mains from the Consumer unit to his rig, and that made sense to me. Simply having the hifi on a separate circuit to to all the other appliances in the house.
Had a quick read up on these balanced mains units, and what little I understood scared me off :doh: I've had electric shocks before, and it's not as much fun as it sounds :(
Pigmy Pony
29-12-2023, 18:03
That is what I have: a separate 32A ring-main consisting of 16 sockets fed by a separate RCBO Consumer Unit connected to the meter via a Henley block.
Does it make a difference? - not that I have noticed, but then I didn’t have mains problems before. I just took the opportunity when the floorboards were lifted to have radiators fitted, to have the new ring installed; thereby reducing the need for trailing cables, distribution strips and other unsightly horrors.
I can't remember off-hand what the source impedance is, but it's about 0.25 Ohm (lower than the usual expected value), and the measured DC offset is < 3mV.
Yes that's what I was meaning, though as has been suggested, improvements will vary depending on how bad things were before.
But how could that last length of cable make a difference? :eek:
Hang on, maybe it ALL does.
100% agree, made a difference at my gaff too.
1973?
Martin, get yer mains sorted Mucker! :ner:
Yes Martin get you wiring sorted - you don't want your house to go up in a nasty fireball - safety first:) Oh and you may find a benefit for your system?:lol:
Our rewire was essential as it had not been done since 1965 but there was plenty of bodging. When the electrician came to sort it he found all sorts of fire hazards and some dreadful electrical installation that could of resulted in death! We found a whirlpool bath had been fitted which involved water, complicated pipework and dodgy electrics.
It could have easily been:deceased:
Pigmy Pony
29-12-2023, 18:24
Yes Martin get you wiring sorted - you don't want your house to go up in a nasty fireball - safety first:) Oh and you may find a benefit for your system?:lol:
Our rewire was essential as it had not been done since 1965 but there was plenty of bodging. When the electrician came to sort it he found all sorts of fire hazards and some dreadful electrical installation that could of resulted in death! We found a whirlpool bath had been fitted which involved water, complicated pipework and dodgy electrics.
It could have easily been:deceased:
Likes to live on the edge, Martin does - I hear he uses his hair dryer in the shower to save time, while his socks dry on the electric fire downstairs :)
It is important to have any mains work done by a professional electrician, or if you have done it yourself, to have it signed off by a qualified electrician.
The Institute of Elecrical Engineers are responsible for the wiring regulations. One of the ways 'new' wiring could be distinguished from older wiring is by the change to the cable core insulation colours (from red/black to brown/blue).
If there was a fire and the cause was traced to any new wiring which had not been singed off and a certificate issued - your household insurance company would be less than impressed.
I bought the house from an electrician.
My post wasn't directed at you Martin. It was directed at those who like to DIY, but are not aware of the latest rules and regulations. Insurance companies don't like that.
Lawrence001
30-12-2023, 00:24
I bought the house from an electrician.But did he give himself a certificate for his work? [emoji23]
Lawrence001
30-12-2023, 00:25
If there was a fire and the cause was traced to any new wiring which had not been singed off and a certificate issued - your household insurance company would be less than impressed.
I imagine most of the wiring would be singed in a fire [emoji23]
That is what happens when you type too quickly. :(
That is what happens when you type too quickly. :(
Was funny though :)
sometimes you just have to roll with it Barry.
Agree on getting everything safety checked and signed off, safety first.
OK
Looking most likely I have quite dirty mains, predominantly from upwards of twenty SMPS in my house and many others in my neighbours.
Over my Hi Fi lifetime I have tried all sorts of mains conditioners and mains reconstructors. None of them met expectations.
So after a good bit of research and listening to advice on various forums I ordered and received a Puritan PMS 156 mains conditioner.
It arrived on Friday and my initial impression is, that its fantastic. Without compromising any of the normal Hi Fi attributes my system is more lifelike, relaxing and listenable. Its removed an underlying harshness that has existed for many years and has caused me to change components and mains cables and interconnects, that were probably not responsible. I have also moved my entire system into four different locations in the room trying to reduce the problem.
It upgrades up to six components at once so looks quite good value for money.
For now, my room is conditioned, my Hi Fi components are isolated and my mains is conditioned. Thankfully this seems the last piece of the jigsaw and its now back to enjoying the music.
I will post a full review later is people are interested.
https://i.ebayimg.com/images/g/zUUAAOSwAQhkOGNw/s-l1600.jpg
Yeah,
should be a good read. :thumbsup:
Have posted a bit of a review here.
https://theartofsound.net/forum/showthread.php?77316-Puritan-PSM-156
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