Is there a need or value for having a power conditioner in place? Say, for instance, the Monster Power Center HTS2500 (approx $300)? Or is this just a glorified surge protector?
I read a post (tried a search) about this topic written by Hawk, a repected regular contributor here and also a great NAD fan. Hopefully, he might respond as he uses a conditioner for "dirty power" issues. I think he would be able to suggest the right one for the money.
There are primarily three possible problems with incoming AC power distribution: 1). power surges, 2). short, transient spikes on the line, and 3). under voltage (brownouts) or over voltage. Depending on your location in the world, one or all three could be a possiblitity. In the USA, the line voltage and frequency are carefully monitored by the local utilities.
Most power supplies, especially switching mode supplies now showing up in some 2-channel and HT receivers, are generally tolerant to under and over voltage - to a point. The real problems are major voltage surges or spikes (transients) on the line. Spikes are typically caused by inductive devices (i.e. motors) or other devices present on the line. These spikes can be as high as a few thousand volts, but very short duration - measured in microseconds or milliseconds.
There certainly is some validity in protection against surges and spikes, but this is a market rife with "rip-off" products. Many so called "power conditioners" have only MOV's (metal-oxide varistors) across one line or more (hot to ground, neutral to ground, and hot to neutral) to surpress short-term over voltage conditions or spikes. And, an MOV only costs pennies to buy! Other products include well-designed "brute-force" inductive and capacitive circuits, as well as MOV's.
One of the best power conditioners is a computer UPS system, but one that outputs a true sine wave. Many of the more cost-effective UPS designs ouptut either a square wave or sawtooth wave under no power conditions. But, all include quite good power conditioning and isolation when power is present.
Be careful when buying "power conditioners," as most linear and switching mode power supplies used in current receivers are well designed and have a fair amount of protection built-in. The "power conditioner" segment of the electronics industry is known for its extremely high profit margins, and questionable merit for many applications. For example, the high-end audio market has several extremely expensive AC line cords available - some which cost more that $1K. This is absolutely a "snake oil" product, as I can prove to anyone that there is no difference between the operation and functionality of the standard OEM AC line cord and one of the audiophile-grade super expensive line cords.
I would strongly suggest you look at power line conditioners from company's that have been in the power distribution business for many years, such as Tripp-LITE, APC, and others. You will spend a lot less money, and get one that really works.
I found a thread for this under Accessories\Power Conditioners after my initial post. Thought I had posted a previous apology for putting it under Receivers but it looks now like it didn't get posted.
i was under the impression that proper power conditioners really do filter line noise out. i remember reading one unit's specs that noted noise rejection levels in decibles and another's that used percentages.
i too am dubious of many "snake oil" claims in audio magazines, particularly regarding CD demagnetizers. CDs use aluminum which is non magnetic first of all, and second of all CDs use optical reading, not magnetic. that one really gets me!
as to power conditioners, they would seem to make sense if you've ever gotten radio bleedthrough or motor noise in your system. i have.
i can't say one way or another if power conditioners actually work, but i do agree that $3000 units are obscene.
if you want the best value in a power conditioner, just buy a professional rackmount unit. they're big, ugly and have those pop out lights, but are easy to find for under $100.
i would think that there is merit to using power conditioners, otherwise one wouldn't see them in virtually every pro audio rack.
from what i've read here and there, digital circuits in particular tend to be fussy about power supplies. while not directly related, my DVD player totally distorts my television screen with noise whenever it's on. i imagine it's a ground loop problem that wouldn't be cured with a power conditioner as they'd share the outlet, but i'd think that a conditioner would reject noise from other ground loops before my outlets.
p.s. sandfilling speaker stands and higher grade cables DO improve sound.
I use an APC UPS as well. You can get a 500V 6 plug/3 with battery back up APC UPS for $23 after rebate at Office Depot this week. It is $49.95, add paper clips for free shipping (has to be over $50), there is a $10 off coupon floating around the net and a $20 mail in rebate. With tax it is $23 and change in NYC. I can't speak for this units performance in particular, but I am sure that it does as well as other UPS units. I wouldn't use it for its backup capability on a stereo, but as a power conditioner, it should work fine.
All: I have 4 American Power Conversion APC 1500-RS units in my home. One of them is connected to my rack. The APC 1500 has been the best and most reliable UPS I've had. (I've sent back my CyberPower 2000VA twice so far for battery problems.) One of my APC1500s has the BR24BP extended battery as well.
I like their units. Mine is more expensive than the standard units, but my AVR-525 draws 1040W at full power and I think I should have a UPS that can handle that for a few seconds easily.
My reason for putting it with my rack... is to protect it from Noise and Power Surges (Brownouts/Spikes) -- hey I live in Florida! Major importance is that this particular unit doesn't switch to battery for quick over/under voltage conditions and why it costs more than the standard "PC" UPS units.