I'm picking up a 7100 and currently I have an APC 1100VA UPS protecting everything in my home theater. Why is posted below, but ultimately, is this a bad idea?

Thanks.

-- Res

I picked it up when I got a RPTV because my area seems prone to terrifying lightning storms. I've had it there a over a year now and except for generating a nasty buzzing sound in the audio when the power goes out it doesn't seem to be hurting anything. As a note, I don't leave things on in battery mode, I immediately shut down and unplug. I often do that before the power goes out if I think it's pretty likely.

As the system incorporates higher end equipment like the Outlaw, I want to make sure I'm not risking damaging anything or introducing a bunch of noise into the system. I have some flickering in the video I recently noticed that I can see when the screen is mostly black. It is particularly visible during the credits for the LOTR. I have not figured out the source yet and I'm planning to try without the APC in circuit and see it thats the source.

A UPS imposes a limit on the amount of current available to the connected equipment whether operating from the battery or from wall power. Power amps can easily draw large amounts of current, thereby running into the limit of the UPS. Good surge protection is highly advisable, but I'd recommend not using a computer UPS for this task - products from companies like TrippLite, Panamax, or Brickwall would be a better choice for protection of home theater equipment. If you do have serious electrical storms in your area, you could even consider surge protection at the main panel. Such equipment is reasonably priced, although it's best to get a licensed electrician to install it for you.

The buzzing you hear is likely due to that fact that, except for some specialized UPS units, when in battery mode, the output is more closely akin to a triangle or saw-tooth wave than a sine wave. While computer power supplies are meant to handle a power source with a highly imperfect sine wave, many other electronics are not. It doesn’t necessarily mean that these electronics will be irrevocably harmed by using saw-tooth wave power, although some might be harmed, it’s just that, for the most part, these electronics will not perform properly while on imperfect UPS power. My personal evaluation is that a clean cut in power that stays off is better than a UPS, but that several seconds of wildly varying voltages or on-off-on-off-on-off power during a lightning strike or before a power cut out would be more harmful than UPS power. A UPS will also switch from mains power to battery power should the main power be outside of certain parameters, not just a power loss.

If there were a way to have a UPS that is not overburdened by the equipment load, and can produce or be filtered to produce power closer to a sine wave, that would be an advantage. But don’t just put a simple surge protector after the USP unit. The sacrificial nature of some surge filters would simply present an additional load on the UPS in battery mode because these filters would try in part to drain off the higher frequency harmonics of the 60Hz power that constitute much of the saw-tooth wave output. There are power conditioners that would do the job properly, but that is an added expense, perhaps even more than the UPS, so perhaps the thing to do, if one is going to use a UPS, it to use one that has a near sine wave output and can handle all the load you intend to place on it. Because most solid-state power amps run, on average, below half of their maximum power consumption rating, if you are not constantly listening at outrageous volume levels, it may be safe to not have enough UPS coverage to run your system at absolute maximum output, but do use a UPS suited to the task.

There are some "audiophile" UPS products such as THESE or THIS ONE . I cannot say how these work since I have not tried them out. The Panamax unit seems more reasonably priced for an audition, so I may give that a try in my system.
In any case none of the units I have seen look like they would work very well with power amps that draw a significant current so I would not feel good about plugging my amplifiers into them.

I use a fairly beefy UPS in my system for two purposes:

1. To power certain components during a power failure. (Basically never having to "reset" my VCRs or other devices!); and

2. To provide surge protection - and protection during that wobbly period just before and just after the loss of power.

I don't use it to provide UPS power to anything that draws much current. My 8 power amps do however all run through its surge protected outlets.

In essence all 35 or so powered components in my racks all run through this single UPS. (Again, only the low current draws are connceted to UPS outlets.) During the great Hillary Clinton-caused power failure of the summer of 2003, everything came through just fine, even after many hours without any power, and several wobbly minutes when it came back on. Not one VCR clock to reset!

I ordered a bunch of Tripplite products that I believe were delivered to my home earlier today, mostly to replace some of the cheap power bars that I'm currently using. I appreciate BB4TB's cautions regarding using them in series with a UPS. I'll have to give some thought to how best to make use of them. I'll probably run only VCR's and stuff that has volatile settings off the UPS (without Tripplites); continue to run the power amps off the surge protected (non-UPS) outlets on the UPS (without Tripplites); and use the Tripplites for everything else.

Jeff Mackwood

I believe that there are some surge protectors and power filters that provide not only a drain for spikes and other oddities outside of the 60Hz sine wave, but first resist them. If a product like the Tripplites you have purchased has multiple stage filtering, similar to a loudspeaker’s crossover that passes lower frequencies to the woofer while first blocking, then subsequently draining, then perhaps further blocking, then perhaps further draining high-frequencies, the Tripplites may provide no significant load on the irregular wave provided by the UPS in battery mode. Perhaps the Tripplite web site will have some details to offer on the models you bought.

If I were using a $7 power/surge protect strip from MalWart after the UPS, I would be tempted to cut the connection to the MOV component so that the strip functions only to distribute power.

From this web page :

“Roughly speaking, surge suppressors work by detecting over-voltages, and shorting them out. Think of them as voltage limiters. Line filters usually use frequency-dependent circuits (inductors, capacitors etc.) to "tune out" undesirable spikes - preventing them from reaching your electronics.

“These devices come in a very wide price range. From a couple of dollars to several hundred. We believe that you can protect your equipment from the vast majority of power problems by selecting devices in the $20-50 range.

“A word about grounding: most suppressors and EFI filters require real grounds. Any that don't are next to useless.”

The greatest advantage of an UPS is for data protection for use with specific equipment that has recording or writing capability (DVD/CD recorder, PC, DVR, VCR, etc.) during an outage or brown-out.
It could also be useful for maintaining the 'cool down' cycle of a projector, by allowing you time to shut it down manually. I don't think the switching supplies in most electronics will be harmed by using a conventional UPS with a square wave for the short time required to shut down a system. Especially, compared with some of the ugly AC that exists at the outlet during brown-outs, etc.
Beyond that, many other solutions are out there that offer great surge protection. I like the Panamax method of removing power in the event of major AC over and under voltages. Afterall, no connection is the best protection.
ZeroSurge and Brickwall provide excellent surge protection and are designed to be used right at the wall, even before an UPS unit.
From there, pure sine wave UPS, combined with regulation are available. This is probably most useful if you want to ride out the storm, so to speak, and continue to enjoy your entertainment during an outage, etc.