UPS vs expensive A/V power conditioner?

The only legitimate reason for a "audiophile" grade power conditioner is looks. Computer UPS units are ugly! So if you like brushed aluminum trim and fancy blue LED displays get an audiophile unit.

If you are serious about power protection just get a Home Depot surge strip. It will do everything an expensive audiophile power conditioner does except look sexy in your rack.

If you have seperate high power amplifiers, do not plug these into surge protectors. Big high power amps are basically immune to power spikes because their power supplies are well, big and tough. An AV receiver is a quandary because while the computer processing circuits will benefit from power line filtering, the power amp section will not. Line filters restrict current spikes and in turn they can limit the dynamics of high power amps.

As for UPS units, they are great for satellite, CATV boxes, media servers but not so much for AV gear. Most of the cheaper units output highly distorted waveforms when running on battery instead of the relatively clean 60hz sinewave the utility supplies. This is OK for TVs, DVD players, and other "digital gear" but not suitable for fine audio gear with linear power supplies. You can get pure sinewave UPS units but they start at over $1000.

I just use an UPS but that is mainly for the projector if I take a power hit. It lets me shutdown the PJ and let the bulb cool. I have my other components connected to it such as the DVD and AVR in case of a flicker or brown out that wayeverything keeps running.

Audio, stripped down to it's essence, is essentially the modulation of the power we feed out gear with.

Glimmie always makes good points regarding these issues.


"If you are serious about power protection just get a Home Depot surge strip. It will do everything an expensive audiophile power conditioner does except look sexy in your rack."

But I respectfully disagree, if one is serious about power quality/surge protection/isolation, etc, there are some superb offerings, however quite expensive. Building an iso system large enough not to impede current delivery is expensive. One mfr, Plitron, makes the best toroidal iso transformers for such duty.

Torus, employs Plitron transformers, combined with other surge components, and offers what I'd consider the finest surge/iso gear out there. Their RM line, albeit very expensive, is outstanding.

I know another approach, a regeneration/UPS product. from Purepower. An AVS'er I trust without reservation, utilizes one of their products on his front end components. He tried it on his active mains, however it made no discernable difference. However used on his front end gear, it made positive improvement.



Some products actually detract significantly from merely plugging into the wall. So above all else, do no harm.

Whose house is that, and what the heck scorched the wall??

Well if you are talking about an isolation transformer, that's a bit different than these overpriced boxes with some MOV's and chokes, ala Monster Cable. I too have a central balanced isolation transformer feeding all the AV gear in the house.

An isolation transformer is IMO, one of the best protection devices as not too much can get through it in terms of damaging spikes. In commercial broadcast / AV facilities, good engineering practice is to always install an isolation transformer for the "tech power" buss if not putting in a large central UPS.

Regeneration is good too but it's nothing different than an "online" computer UPS unit. And while a good Liebert or APC costs over $2000, it's still a lot cheaper than a Richard Gray or similar and does the same thing. In addition to the balanced power system I have Liebert 3KVA unit on my digital gear. I got it free as it needed new battereis - a $200 investment.
Edited by Glimmie - 3/9/13 at 5:45pm

Holy #$%^! Now he has to explain that black burn om the wall. Did someone axe through that feeder?

I purchased an APC power conditioner with battery backup mainly for protection of my pj. This it the APC model I have.....CLICKIE.

Overkill, maybe but it has come in handy a couple of times when there have been power issues at the house everything I have (except the sub and the amp) is plugged into it..

Regards,

RTROSE

Is there anything like the EquiTech 5 or 7.5WQ wall unit that would be $4,000 or less out there?

My cox cable installers last day on the job. He was drilling a hole for the line. I was standing inside. He hit the main feeder cable and it was like a magic show, a cloud of smoke and sparks. After I made sure nothing was burning I went outside and the guy was clueless that anything had happened. I told him he had hit the main line and when he looked at the drill it was several inches shorter. His supervisor came out and then called in an electrician to fix the line, the bill was $600ish that the supervisor put on his CC. The installer said it would propably be is last day and he was planning to start his own structured wiring company to tap the new home market. It was hard to keep a straight face.

I have since built a more appropriate shelf for the UPS to sit on. It has been called into service 1/2 dozen times since I've had my theater.

I smell snake oil.

What's the scorch mark from, and what is that SPD connected to?

Does a step down transformer = isolation? Does it provide balanced power? My electrical was put in to Dennis / plan specs with a 240v line to the equipment room and a bunch of junction boxes leading to the theater... but I'm not sure what I'm suppose to do with any of it. I assume 240v goes in and multiple 120v come out which are attached to the junction boxes in the equipment room to essentially power everything in the theater (including lights?). What is normally used for that and is it overkill for home use?

I am looking at this to plug in to Dennis' 240V 30A twist-lock outlet:

http://www.exactpower.com/products/rmpcore/rmpcore.aspx

or this:

http://www.middleatlantic.com/power/IsoCenter.htm

For a UPS, I am looking at this:

http://www.tripplite.com/en/products/model.cfm?txtSeriesID=937&txtModelID=4534

The Richard Gray junction boxes are probably intend to feed powered speakers in the theater.

I would not run lights off of this system -- that is a complete waste.

Any true transformer provides isolation. An Autotransformer does not. Balanced power is simply a special transformer that has a centertapped 120v secondary. You ground the centertap and get 60-0-60 volts versus 0-120. This however is an exception in the NEC and not allowed to be hardwired into a building without special considerations. And I don't think it can be installed in a residence. A balanced power system that rack mounts and plugs in should be OK per code.

240v to a theater room? Here are the options:

1) Feed a subpanel and split out 120v circuits from that. The benefit is less wiring back to the main panel.

2) Feed 240v to a transformer box with 120v outlets on the back. The models listed in the above post are such units. This is a good plan IMO.

Note that most single family residences in the USA are 240v phase to phase. Three phase systems such as in commercial buildings and some apartment buildings are 208v phase to phase. Make sure you check this before buying one of these transformer units as you need the right voltage unit. If just installing a sub panel, it doesn't matter as both 208v and 240v systems provide 120v to neutral.

Also note that "all AV equipment on the same phase" requirement is a consumer audio myth. Go into any Radio station, TV Station / mastering facility, or major recording studio and you will find three phase power. There is no standard as to what equipment goes on which phase other than to keep the phases reasonably balanced like under 10%. You do need to keep neutral current to a minimum and perhaps the moving of equipment to different circuits for phase balance reasons is where this misunderstood myth developed. Isolated ground systems are common but even these are falling out of favor due to cost as most gear today is digital or even IP based and pretty much immune to ground loop issues.
Edited by Glimmie - 3/11/13 at 1:26pm

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Thanks Glimmie and LeBon.

My plans didn't call for the twist lock receptacle. As far as I can tell, only the Richard Grey transformers use the non-locking plugs so my options appear limited unless I pay the electrician to come back out and change the receptacle (assuming they are interchangeable).

Do you know who makes the transformer in the IsoCenter?

That should be an easy change. They even sell twist lock receptacles at Home Depot. But at today's electricians rate's I'll bet that's a $100+ service call.

They also sell adaptors to and from 20a twistlocks as they are popular on construction sites.

Or you could even replace the plug on the unit but that would probably void your warranty..

Richard Gray PowerHouse is a rackmount 240V30A step down transformer providing balanced power out.
The ExactPower is a 240V30A rackmount step down transformer without balanced power out.
Both utilize a 240V30A feed. Richard Gray uses a NEMA 6-30R recepticle ... Exactpower a L6-30R ("L" for "locking").
Lights are not fed from the step down transformer...especially if you have them on dimmers.
Transformers (as Glimmie said) are great isolators. Balanced power can have better noise/spike rejection.
Most battery back-up units will not tolerate balanced power! This means with a balanced power transformer the UPS system would have to be installed between the power source and the transformer...which also means it must have the same, or better, kVa as the transformer.
While isolation transformers are great for spike protection, they do little to nothing for sags and brownouts which, BTW, are the bigger cause of failure in today's electronics, wall warts, power supplies, etc.
I prefer to have a 6kVa to 12 kVa UPS in the system...best when you have a good control system. A good UPS system will protect against sags/brownouts. With a good control system, when a power problem is detected, your control system can be programmed to run your entire system (runtime depends on load and UPS capacity) for a period of a few minutes. If power is not restored in that time frame, the control system does an orderly system shutdown and the UPS would have enough energy left to maintain equipment fans (like the projector) to provide proper cool down.

Clearly, spending more on step down transformers and UPS systems than you have spent on your equipment would be tough to justify; but, if you have a $30k better projector, the value proposition improves (also if you have a generator in your home, UPS+transformer should be on the list. Spending $8K or better to protect a $5,000 projector wouldn't appear to be justified. Also, a good idea to review your homeowners insurance policy to determine just what your insurance company will pay for electrical damage to your electronics and under what conditions.

Can someone recommend a decent (~$500, probably 1500 or 2000 kVA) online UPS that will regulate brownouts and is silent?

Isolation transformers will address under and over voltage conditions if they incorporate a tap switching feature on the output transformer windings. Torus Power's AVR line do this. They will keep the outbound voltage at 120V for a wide range of input voltages.

The only advantage of a dual conversion UPS over an isolation transformer is that they will cover you for outages. The downsides are numerous: relatively low efficiency, high running costs, lots of circuitry to go wrong, noisy, limited ability to supply dynamic current.

All bulb based projectors should ideally be on a UPS unless they have an onboard battery backup for the fans.
Edited by Nyal Mellor - 3/15/13 at 2:29pm

Torus makes good stuff and you've been listening to their pitch; but, nothing is for free ... so when when the input volts sag that voltage has to be made up. So for short term minor sags OK. Other than that, nope.

Not sure what you mean by "other than that nope"...these types of isolation transformers are just changing the ratio of turns input:output to maintain the output voltage for a range of input voltages...no downside

How is the tap change accomplished?

A motorized variac has been used but the draw back is response time.

SCR's could be used to zero cross switch within a cycle but would generate spikes as well. If done on the primary side, the transformer would help to filter them out.

Relays could also be used but now you have a response time issue again with the addition of spikes and unpredictable switch time to boot! You can't time a relay to reliably switch in a zero crossing cycle of 60hz

Tap changers, both solid state and relay as well as motorized variacs have been around for years. They work well in many applications. I just don't know if I would put one in an HT.

Then we also have the old ferro-resonate transformer. These are only efficient if fully loaded and produce significant waveform distortion.

But honestly we really don't need this regulation at all. A line voltage variation from 105 to 125 volts is not going to hurt anything in an HT. Only the power amp will suffer from reduced line voltage and that will only be reduced full power output - which we would never use anyway in a good room. Most all other gear is regulated internally. Switch mode power supplies typically work from 87 to 260 volts. So they are highly immune to voltage sags and peaks. What they are not good with is high voltage spikes. So this is why surge protection is a good idea.

....Glimmie, what have you seen with amp swings?

this thread just got uber useful

Nothing really. I am just pointing out that a line voltage reduction will decrease the available full power output by a usually small percentage. Will it be heard? I doubt it because home power amps are rarely pushed to the limit by their owners. Now a teenage son/daughter party with the parents away is an exception .

I don't know about the rest of the US today but my line voltage is 120v dead on most of the spring, fall, and winter. In the summer I have seen it drop to around 110 on a hot day.

NOTE: I am referring to a typical class B power amp with a basic unregulated power supply. Some amps these days have switching power supplies and those too would not suffer from line voltage swings. And let's not forget the infamous Dynaco 120. This was 1966 classic that actually had a linear regulated power supply!

Never take anything for granted about the power you are starting with.

Four years after moving into my current (sorry, no pun intended) house, I started having issues with appliances. My Revox system "failed". $1600 to Revox later, I plugged it in and it "failed" again within a month, which unfortunately coincided with Revox pulling out of Toronto...Canada...and the World. One TV, a Sony theatre Receiver (I know), 3 sets of $140 motor brushes for the European washer and a new motor and heating coil for the dryer, new dryer, countless light bulbs..........It dawned me that there might be a problem. I had talked to many people from the trade and the Utility and checked just about everything about the wiring, except the line voltage! Get out of the box! ...But no one else in the neighbourhood was having problems!!!

It turned out that Hydro had fed two blocks of houses north of me from different supply lines on the street and left me alone on the line heading "North" from the transformer at the end of my driveway. In addition, the connections at the transformer were loose and arcing, the tap was left at +10% and the oil was way low (old transformer). I was getting 130V and 132V on the two legs. And this is before any spikes. I may be wrong, but I don't think surge protectors would have protected me from this!

It has been fixed with a new, much bigger transformer and I now have very stable power at 124V. 100W bulbs now burn at the brightness that 60W bulb did! So I feel like I'm going blind. We don't seem to have problems with brown-outs, just the very occasional outage during a storm, because of our aging trees.

As a precaution, I have installed a surge protector on the first taps of the panel and have, at my electronics service guy's recommendation, installed ups' on critical equipment. My stereo is on the line through, so that it is protected by the transformer only. Having it on the battery back-up was too painful to listen to at the beginning of a power outage, or when the battery started to fail for some reason.

I replaced the Revox receiver with a Mac 4100 which claims not to need or want a power conditioner, I suppose because of the size of their transformers and special power management circuitry (1978 vintage!!!). My new Mac's (1990 ) also don't want conditioners.

After 2 years of fighting, Hydro finally gave me a cheque for 80% of my claim with of course, no admission of guilt. It's ironic that 2 dogs got a shock off a brass cover in a public sidewalk that covered some wire connections. Hydro had no problem spending what came down to an average of the ridiculous sum of $1000/box to inspect all the boxes in the city....millions of $$$.