Audiophiles: Power conditioning?

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SinShiva

Limp Gawd
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Nov 20, 2009
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Are standard surge protectors up to the task?

http://hardforum.com/showthread.php?t=1724108 guy getting EMI from a washing machine to his computer's audio. OP says his system is plugged into a "surge protector (UPS)", so, not sure which it is, exactly.

Anybody using dedicated, more expensive 'power conditioners', emi filters/ac line filters ?

I saw on various sources around the internet saying this is all bologna, but i imagine there's things like radio/transmitter equipment that'd be sensitive to EMI from all sorts of things. i guess some people have been saying you can get cleaner video (blacker blacks..,) which sounds maybe possible with CRTs, but i can believe it when it comes to audio equipment.

do they get by on slightly more reputable, but still cheap surge protectors or do they need something a bit more [H]ardcore ? :p
 
EMI is a poor choice of condition when talking AC mains power.

Also, it depends.

Some areas have notoriously poor voltage stability, and depending on what other devices share your audio equipment's circuit, you could see a change when using power conditioning.

That said, there are a few major points to consider.

High quality (but not necessarily expensive) audio devices have filtering built into their designs. So even if your mains are dirty, you are likely already covered in some way. A dedicated device may have better filtering than what is inside your audio device, but it is definitely not something you should assume.

Likewise, not every washing machine, etc., will pollute the circuit it is on. In fact, they really shouldn't, and therefore good ones probably will not.

Also, not all power equipment is created equal. A UPS, for instance, may only work as a surge protector when on AC power, unless it is online, which is unlikely for consumer units. Similarly, not all power conditioners have the same features.

In my experience it is not line filtering that makes a difference, your audio device probably has that already. True voltage regulation via boost/trim, however, might.

Have you ever had your lights flicker when your AC kicked in? This is due to a momentary drop in voltage in your building's electrical. It shouldn't happen... but again, in some buildings it does.

Or maybe you live in an area with brownouts, where your area's line voltage will drop by 2-3+ V during heavy usage times.

In these cases your audio equipment will be seeing out of spec mains power. The delta, unless it is significant, probably won't harm your device, but since, unlike line filtering, most audio devices do not have true AVR (automatic voltage regulation) a power condition with AVR may make a noticeable difference.

So there are two main points at play here. First you need to determine if your mains power needs any help. For the majority of people, that answer is probably no (excluding warmer climates in the summer which will see mass AC usage). Then you need to choose a unit with the features you need and not one with the best sales pitch.

Personally, I use multiple APC H15s, which sport true AVR, for most of my gear. The reason? My building experiences brownouts.
 
thanks. i lived somewhere that got regular brownouts, which lead to my finally buying a UPS. I personally have never experienced unusual 'hiss' or whatnot from my audio equipment, at least with the surge protectors and UPS i am using, but i'm in a pretty small house now with very recent electrical work done.

so, i take from this to mean that unless you are getting voltage fluctuation, pretty much everything offers some level of line filtering and there's not really any reason to have a dedicated device 'cleaning' the ac?

good to know, and thanks.
 
SinShiva said:
thanks. i lived somewhere that got regular brownouts, which lead to my finally buying a UPS. I personally have never experienced unusual 'hiss' or whatnot from my audio equipment, at least with the surge protectors and UPS i am using, but i'm in a pretty small house now with very recent electrical work done.

so, i take from this to mean that unless you are getting voltage fluctuation, pretty much everything offers some level of line filtering and there's not really any reason to have a dedicated device 'cleaning' the ac?

good to know, and thanks.
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It entirely depends on what you're doing.

In professional stage audio, we have to use clean power. Otherwise all manner of gremlins can come along. Even high-end professional gear can sometimes not deal with unclean power. Depending on the gear and exactly what is going on. Every time someone wants to hook up a laptop or an iPod to our venue sound system (2500 seat roadie house) we always have to break out extra hardware (DI boxes), we can't just direct send it to an audio console, because the grounding on standard 3.5mm audio jacks in every iPod and MacBook ever produced the world over blows ass. If we don't it is noise city, or we get ground loops, or distortion, you name it....but that is taking an iPod singal and cranking it enough to fill a 1000+ seat hall, with a sound system tied in to a 200A 240V 3-phase safety switch.

For normal household usage, you *probably* won't notice a difference...and odds are if you're cranking you amps loud enough to notice a difference, you're damaging your ears enough to not be able to notice.
 
alright, say you are noticing 'something' in your audio and you have everything plugged directly into wall sockets. in my setup, my headphones have high impedance, so i'm using a small amplifier. on a household scale, what's the most cost-effective way to make sure you're getting 'clean power' ? will surge protectors or UPS generally take care of this? what are you using for your home theater?
 
SinShiva said:
alright, say you are noticing 'something' in your audio and you have everything plugged directly into wall sockets. in my setup, my headphones have high impedance, so i'm using a small amplifier. on a household scale, what's the most cost-effective way to make sure you're getting 'clean power' ? will surge protectors or UPS generally take care of this? what are you using for your home theater?
Click to expand...

What is the noise? Is it hiss, or beeps, does it sound like you picking up a radio station (yes this last on is possible)? Anything you can compare it to?

It could be bad grounding in the electrical outlet which a cheap ground-lifter from Home Depot could fix, it could be poorly shielded cables picking up EMI/RF. It could also be your source. As you get higher end, it is much easier to notice flaws in recordings (fingers hitting strings, mixing errors etc.)
 
say you hear a slight hiss with no audio playing and popping noises when appliances around the house are turning on and off. with 'perfect' audio equipment, would the hiss be alleviated by a standard surge protector or ups and popping noises mean needing better cabling? 'Blindedbyscience', in the linked thread, mentioned using ferrite covers at the ends of audio cables, would this be a suitable alternative to better shielded audio cables?

ferrite cover thingies; http://www.parts-express.com/pe/showdetl.cfm?partnumber=110-450
 
Ground loops are a related, but separate, issue.

Logistically, for home use, a power conditioner may help eliminate ground loop hum by facilitating a single point of hookup, but really any solution to ground loop hum has more to do with sharing or isolating a ground rather than anything in the filter stage(s) of the conditioner.

I wouldn't call a DI box a form of power conditioning. Its job is not to clean mains power but rather to work upon/isolate input signal(s) and/or their grounds.

If your hum is being caused by an impedance mismatch, level imbalance, signal ground mismatch (when a mains ground mismatch does not exist), or etc., then a power conditioner is not going to do anything for you.

Typically (but not always), when you are talking about a ground loop caused by mains power, it is because connected devices are plugged across two or more outlets, often when at least two outlets are connected to different circuits. In such cases, it is important to note that the ground plugs in your electrical outlets may be assumed to never be perfectly grounded.

This is to say that, the vast majority of the time, no two outlets have the exact same ground, and you will almost never find a grounded outlet carrying exactly 0 volts on its ground. As such, you have the possibility of a mains ground mismatch among your devices.

That said, mains grounds and signal grounds are two different things, and you can still have a ground loop even without outlets as factors. Again, in these cases, power conditioners are not your answer.

As for pure surge protectors and power strips, these do not perform any filtering whatsoever. Many UPS units will provide line filtering, but not all. Many UPS units will also provide some form of voltage regulation by switching to battery when voltage exceeds certain limits, providing some voltage protection, but this is different from true voltage regulation unless you are talking about an online unit, which always draws from its batteries.

As stated, I use APC H15 units for their AVR feature.

Also, do note that all amplifiers have a noise floor. Few amplifiers are truly "black" during quiet passages and gaps. SNR ratios and all that.

Lastly, look for three things:
1. Hum levels remain constant throughout volume adjustment on your device.
2. Hum noise is cyclical. E.g. an audible oscillation. (Generally known as 50/60 Hz hum.)
3. Hum which appears to appear/disappear according to the habits of other devices. E.g. you hear the refrigerator kick in and suddenly your notice a hum.

Any of the above will generally point to an issue.
 
SinShiva said:
say you hear a slight hiss with no audio playing and popping noises when appliances around the house are turning on and off. with 'perfect' audio equipment, would the hiss be alleviated by a standard surge protector or ups and popping noises mean needing better cabling? 'Blindedbyscience', in the linked thread, mentioned using ferrite covers at the ends of audio cables, would this be a suitable alternative to better shielded audio cables?

ferrite cover thingies; http://www.parts-express.com/pe/showdetl.cfm?partnumber=110-450
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In your case, it sounds like noise traveling through the lines in your house.

Inductors like the one you linked to are the cheap and easy thing to try and do. It is best to put them on whatever source is causing the noise rather than downstream just on your audio gear. Before spending lots on UPSes or power strips with filters, they're the easy cheap fix.
 
SinShiva said:
say you hear a slight hiss with no audio playing and popping noises when appliances around the house are turning on and off. with 'perfect' audio equipment, would the hiss be alleviated by a standard surge protector or ups and popping noises mean needing better cabling? 'Blindedbyscience', in the linked thread, mentioned using ferrite covers at the ends of audio cables, would this be a suitable alternative to better shielded audio cables?

ferrite cover thingies; http://www.parts-express.com/pe/showdetl.cfm?partnumber=110-450
Click to expand...

Ferrite beads are for suppressing RF noise in the MHz range and up -- if your household appliances were interfering with your sound system's FM radio reception, ferrite beads might help alleviate it. Hiss and popping in consumer audio equipment is usually just crap amplifiers and crap power supply regulation.
 
Any wire may act like an antenna under certain conditions, especially when poorly shielded.

Roughly, ferrite cores eliminate EMI/RF by trapping it.

If a signal wire is indeed acting as an antenna, a ferrite core will help prevent passing any interference.
 
I think I will invest in a unit with 'AVR' at some point, seems worth having when comparing a lot of audio equipment.

as far as the ferrite cores are concerned, stripka mentioned placing them at the source of the interference. if the source were a fridge, would this mean it's better to place them on the ac/power cable of the fridge rather than on the audio equipment's audio/power cables?
 
i recommend an isolation transformer. Tripp Lite makes them for hospitals, you can find them on amazon very cheap. That's all the power conditioning you need. Bear in mind, they are ugly and extremely heavy.

But they will kill ground loops and most likely give your gear a quieter noise floor.
 
I have a few "audiophile grade" power conditioner and power plant for my gear, only reason is there are lots of interruptions on my line and power supply from the grid here is not clean (lot of background hissing). Cost me $115 each.
 
Skripka said:
It entirely depends on what you're doing.

In professional stage audio, we have to use clean power. Otherwise all manner of gremlins can come along. Even high-end professional gear can sometimes not deal with unclean power. Depending on the gear and exactly what is going on. Every time someone wants to hook up a laptop or an iPod to our venue sound system (2500 seat roadie house) we always have to break out extra hardware (DI boxes), we can't just direct send it to an audio console, because the grounding on standard 3.5mm audio jacks in every iPod and MacBook ever produced the world over blows ass. If we don't it is noise city, or we get ground loops, or distortion, you name it....but that is taking an iPod singal and cranking it enough to fill a 1000+ seat hall, with a sound system tied in to a 200A 240V 3-phase safety switch.

For normal household usage, you *probably* won't notice a difference...and odds are if you're cranking you amps loud enough to notice a difference, you're damaging your ears enough to not be able to notice.
Click to expand...

For MacBooks, why not use the built-in optical audio?
 
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