Hi Nicholas,
I can probably dig up my files, but the model numbers will have changed in the last few years (don't know about the guts, but Marketing says we need new models every six months, right?

) I will try to 'member to check the APC site -- you want to know about the higher-end double-conversion systems for continuous use? Or were you talking about the lab-grade stuff?
BackUPS are not that good, and in fact not rated for motor use. SmartUPS are much better, but they have several levels of technology. The lab-grade stuff is clean but pretty old, and I think the last time we priced new stuff is was ~$25k for a 1 kW system (typo in my first post, sorry). I can look into that as well if you wish, take me a little longer.
A more practical solution might be a SmartUPS system with additional industrial filters or a Sola-type system (resonant transformers) on the outputs to provide better isolation and cleaner waveforms. Probably a lot cheaper than a lab-grade system (<$5k, guessing).
HTH - Don
Hi (Long, Long, Long Post)
This is a great subject in itself.. It is something I have been advocating for a long while in many fora. I have believed in cables personally. I have shelled ungodly amount of money on cables.. My last set of cables would likely allow the purchase of a superb system. The speaker cables would run over 10 K easily …. I am off that wagon after a blind experience I conducted, the experience itself prompted by another a member here had. I wasn’t able to distinguish between my expensive cables and thick 6 AWG cable. Cables used to link DC batteries to AC power Inverters … The sky did not come tumbling down. I simply realized that I had been approaching the hobby in a wrong and expensive fashion. Oh! No! I don’t think that everything sounds the same.. Not speakers, not components, Not DAC but cables.. Good gauge, electrically and mechanically adequate ? SAME…
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Even when I believed in cables, I have, however, never believed in the "magic" of power cords. It could not make sense then and will not make sense now in the future. I have been involved on a practical level in AC Power Quality at my former business. ISP/Service Telecom Provider in Haiti. (For those who have read this already, I apologize). There we had beore the very unfortunate events of January 10, about 40 hours of Electricity a week … We noticed that when using the AC grid we tended to have serious equipment failures .. (Microwave amplifiers would simply die for no particular reason , Satellite HPAs would just go off without notice or Server really misbehaving .. crashing … We met with a FCC fellow , a consultant and he steered us toward the very alien concept of Power Quality and that is when I began to really observe what commercial AC is made of.
First keep in mind that power lines travel for miles in an environment where EMI and RFI are simply part of the scenery .. Wherever we are there is RFI and sometimes High Level of it. If one were to just look at what is coming form your AC mains through an oscilloscope one would be quite edified. On top of the gentle supposed sine wave at 60 Hz rides all kind of nasties .. The signal is too often very far from a sinusoid… We are also supposing it is stable , something it is not .. varying wildly with all kind of brownout ( sudden drop in voltage ) and black-outs .. etc … plus the RFI plus the EMI … My beef has always been what do you think that 6 feet of nice cryogenically treated piece of jewelry , er… cable can do for that, unless it has a real filter in its construction, some may, I don’t know very well if they do but that would require these to be big and with a box at their end something I haven’t seen in any of these nice expensive cables… and it would not solve the problem of stability of Voltage … so there to me they could not work and in my auditions .. well they did never work .. Once I got one of sufficient size .. they simply were the same to me then and more so now …
Now back to my encounter with the Power Quality notion. We went and purchased a Telecom Grade UPS a Lorain Huge, Heavy noisy, they are ferroresonant (not all Lorain but these were) and they were double conversion UPS ( Rectifier , Battery in the middle and an Inverter at the end ..)
AC -----[AC to DC rectifier] -------[Batteries]-----[DC to AC Inverter]
In the better system the DC to AC inverter provide a pure stable solid sinusoid .. In my Lorain which by the way survived the catastrophe, you get 120 VAC with plus or minus 5% of voltage regulation at 150% maximum load, the unit is conservatively rated at 10 KW but would work forever at 15 KW not KVA , no Sire WATTS!! At 3% of THD at full capacity regardless of load capacitive, resistive, combination of LRC it does not matter… Oh I was going to forget frequency regulationin the Lorain was better than 1%!! What the load sees is the clean, stable, distortion-free current from the inverter regardless of how dirty or instable the AC mains are. In a double conversion UPS all the AC mains is needed for is to charge the batteries.. the rectifier are usually stout to take any kind of poor AC mains you can dish at them and the batteries take over when the main really are not up to it … Big frequency variations , voltage drop or over-voltage.. brownouts, black-outs, etc
I wasn’t ready to believe that would make a difference but it does , The system sounded to me better, changing to regular AC was very audible. I did not care to go further.. My system was sounding much better and actually it make sense since the system receive what it was design for .. Pure AC , something the commercial AC can’t provide and something NO Power Cord regardless of price can’t fashion out of nothing …
Now about Audiophile conditioners … Don’t start me here but I can say that there are about one or two models I know to do just that.. Basically regenerate the AC .. I know the Burmester 948 does that, I have never used it…. I know the PS Audio does that too … It produces its very own AC and if one has to be an audiophile AC conditioner that would be the one, decently priced too . . I don’t care about the trickery of doubling the frequency, etc … but it is a sound idea… and likely makes your system sound better
And there is the Equitech which is a little different .. Suffice to say that it splits what comes from the AC in two with respect to ground now at 180 degrees of phase difference. +60 and -60. The noise from both sides cancel themselves out quite well. I still don’t know how do they provide voltage regulation. The system can’t do that and thus assume your AC is stable .. Often a HUGE assumption. .. and to be on the safe side they use a rather big isolation transformer which further filters out the EMI and other higher frequencies nasties … It is a very sound product and I have no doubt that the differences are audible and that once you used it All electrically good cable become the same …
I have not used the Equitech personally. It is however scientifically sound and to me that counts .. I am not on the wagon of these quantum treated items ..that can’t work because well their explanation is nonsense .. As for serendipity … one has to wonder how these guys get to have so much of it on their side …
Now about APC .. There are many good brand of Double conversion UPS , Lorain for one, Sola, Liebert, There was Best Power in the past, I don’t think they are in existence. These can be found if one looks hard for them but they are often big big and unwieldy. I don’t see these very easily in a domestic environment, next to your amp for example… If one has a generator and utility shed … well .. In Haiti that is almost a requirement to have electricity in one’s home on consistent basis with those 30 hours of electricity a week … Back to APC … This brand is almost synonymous with UPS . They make cheap, small units that ost people know about , ths Nicholas earlier post … The double conversion units start at a size about as big as an audiophile amp. I suggest to start with those at 3000 VA which I have experience with. These should provide enough power for most systems. The price (about $2500 for a $3000 VA) is squarely in what audiophile do spend on their specialty power cords and they will trump ANY audiophile power conditioner for the price .. No they don’t have cryogenically treated outlets but one could always replace theirs with those. As for NEC compliance I don’t know but your electrical contractor.., the same one you used for your “dedicated” lines to your amp would give you a quotation. ( I don’t believe that dedicated lines are much of a solution, since the same AC is split from your main box .. SAME AC. The only thing you have “dedicated’ to your system or your amps is a breaker .. You continue to share the same AC as the rest of the house and all induced noise is share too )
The benefits of pure AC in your system are Immediate. From my experience the noise level of the system decreases .. yes the sound changes .. I will not use any audiophile term.. Oh Heck I will: blacker background

…etc. Your system is protected, it never sees the AC mains and whatever happens there doesn’t affect your system short of a direct lightning strike and even in this were to happen the rectifier is likely the one to be shot first … and you get to play your equipment even when there is a blackout albeit for only a few minutes..

The APC line what would qualify are not these puny noisy boxes people put on their PC .. the BackUPS .. You need to start with the Line-interactive biggies at least 2000 VA
Something like
THAT ONE whose price is $2700 … it will provide easily 2100 watts to your system unless you use monster amps that is enough for the most powerful systems and they have models up to 30 KVA so... yes .. Mark Basspig, you could use one in your system too

…
If that is OT .. we can always move this in another thread …
P.S Don, $25 K for 1 Kw is very unlikely ... I don't know ANY UPS with that kind of price ... even Teleco-Grade -NEBS level 3 are not priced that high ... Very unlikely ...