Cleaning up power - UPS or other power conditioner?

I live in an old neighbourhood with notoriously bad electricity. We regularly have “brown outs” where power doesn’t go right out but dips from the standard 120 VAC to as low as 90 VAC (according to the guy who replaced the main controller PCB in my fridge anyway).

I’ve got my NAS and ROCK on a standard APC Uninterruptible Power Supply (UPS) in my basement but I’m now thinking about my listening room.

In my listening room I’ve got a tube integrated amp, a separate phono preamp, turntable and RPi with Allo Boss DAC as a Roon endpoint.

Do you think I should invest in a power conditioner? Can I get away with a UPS? What do you use?

I have terrible AC, and it gets worse once it get into the house.
Had real problems.

I use a PS Audio PS10. It recreates clean AC, essentially it is a big power amp. Have had no problems since then.

A UPS has the purpose of avoiding outages, but not to create clean AC or eliminate noise. I use a UPS for my non-audio computers and backup NAS.

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Full disclosure–I represent a major UPS manufacturer and also some smaller single phase UPS manufacturers so I make a good part of my living selling this stuff.
Most of the APC, Tripp Lite and other “consumer” UPS equipment are a “line interactive” design. That means the UPS comes on line only when there is a power loss sufficient enough to bring it on. And that can work fine if you don’t need a literally instant backup and power conditioning. The gold standard in the commercial UPS world is true, online double conversion. This design runs the power to the load 100% of time through a AC/DC then DC/AC conversion providing instant response and power conditioning in the process. This is almost the universally accepted commercial UPS design and can provide excellent power conditioning.
APC and MAXX Power are two companies that have a full range of small single phase online, double conversion products with a multitude of VA ratings and outlet configurations. The last few years they’ve even prettied them up a bit but you won’t find them at Best Buy–you’ll have to go to the companies websites and search a bit.

So, with an online double conversion UPS you get back up protection and power conditioning.


@AndersVinberg Thanks for the suggestion.

@KenS That’s great info, thanks!

Looks like I’m going to have to spend a lot more than I thought to clean up the power in my house.

A Torus with AVR?

I use a non AVR Torus and it works very well.

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Looks interesting but out of my present budget. That led me down a bit of a rabbit hole though…

I found a 1000VA UPS with Automatic Voltage Regulation (AVR):
Provides clean, consistent AC power by automatically regulating low voltages and over voltages, within defined tolerances, when incoming utility power has minor fluctuations.

@KenS It doesn’t say online dual or double conversion specifically, but how would AVR compare?

I should clarify–If you need a UPS for backup get an online double conversion. If you don’t need a UPS then go with some kind of power conditioner. Any UPS worth it’s salt will have two or more cooling fans which you will hear so keep that in mind. As far as power conditioning I’m pretty old school and would go with a well packaged toroidal transformer at the consumer level . I don’t know anything about AVR and I have no idea how conditioners like Shunyata and others without transformers work. Not saying they don’t because I sell large three phase UPSs that are transformerless and are used just as power conditioners, but I know how they function-- and what they cost.

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@KenS, can you name a line of APC’s consumer grade single-phase double-conversion online UPS’s please? Or any model from the group, so I can start searching for the suitable one for me.

With APC I would look at the 2000 SMT or 3000 SMT depending on your load. With Xtreme Power look at the TX90 series. It has a transformer so a little more conditioning ability. Both are on line double conversion.

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I couldn’t find APC SMT 2000 but found SMT2200, SMT3000 and even SMT1000 and SMT750. Newer versions seem to have a “C” at the end, e.g., SMT3000C. But for all of them the specs say “line interactive”:
Maybe you meant a different line, not SMT?

My bad–not my line and the rep didn’t get it right either. Check their SRT2200XLA or SRT3000XLA

That’s it. Thanks! The SRT2200XLA is probably an overkill but there is an SRT1000XLA with 1000VA power. Costly but nice. Output Voltage Distortion - Less than 2%. Sadly the efficiency of these is lower than line interactive’s but it’s their nature.

Yes, the efficiency of any online UPS is lower than line interactive because it’s doing more, all the time. The APC units have a “high efficiency” setting which will put it in line interactive mode so avoid that, With 1000VA you won’t be using much power anyway. I haven’t heard those particular units but I imagine you’ll not want them in the listening room.

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I suppose you mean that the fan is always on because the inverter and the charger are always on. That would be inconvenient… My current line interactive APC UPS’s turn on the fan shortly after they go into battery mode and when charging afterwards. I would not want this fan to stay on all the time.

Unfortunately it would defeat the purpose of power conditioning.

The fan(s) won’t run 100% of the time. It will depend on the load,and ambient temp. They will run when the unit is on battery.

The double conversion on-line is always “on battery” - the inverter is always on, and so the charger. Why else did you think it could be noisy? If I didn’t misunderstand you when you said “you’ll not want them in the listening room”.

You’re incorrect. The only time a UPS is “on battery” is when the utility power is diminished or gone. Then the UPS goes to battery and will support the load as long as it’s batteries allow. If you mean the UPS is constantly charging it’s batteries then yes. We may be mixed up with industry jargon here.

I put “on battery” in quotation marks. I meant it is in the same state as if it were on battery, i.e., the inverter (DC->AC) feeds the load, and the inverter is fed by a AC->DC rectifier that is also a charger. So, the inverter is always on. Page 5 of the APC whitepaper:

When my line interactive UPS is on battery the inverter buzzes and after some time the fan comes on and stays on for some time after the power returns, during active charging I presume. Since those online UPS’s inverters and charges are always on I thought they would have an always on fan.

Can you explain what you meant by saying “you’ll not want them in the listening room”? Are they loud?

Semantics at work here. In industry speak, even thought he batteries are constantly being charged and not supporting the load, a UPS is “on battery” when it’s batteries are supporting the load with no utility power available. Since an online double conversion UPS is just that–on line-- it’s fans will run nearly all the time since it’s inverter/rectifier are running all the time. “Loud” is up to you to define.

I use a PS Audio Perfect Wave 10 power plant and also PS Audio AC 12 power cables and wow did these (both) make a significant difference in cleaning up the power and improving the sound to my systems. I’ve got experience with a lot of power cables and these are the best I’ve yet had. It is a lot of money but if it’s in your budget you’ll likely be surprised by how much better things can sound with good power.

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