Thank you for asking this very question as I have been thinking about this the last couple of days. I have a Pass X1 pre amp and a Pass DAC 1 that do not have power switches, so they are always powered on. In a recent power failure the DAC 1 got fried. Pass Labs fixed the problem. It sure would be nice to have a back up battery on equipment that can't be turned off to protect from these situations. APC seems to make new conditioners / back up batteries for audio equipment. Anybody know about these products? |
I have used Tripplite line conditioners and UPS.. and even an APC UPS but they make an audio system sound awful!! I used a Tripplite LC1800 and it still limited current. The sound was totally closed in.. and worse yet the power switch went up in flames one day... and I threw it in the garbage..
DO NOT DO IT!!!
There are plenty of audiophile conditioners that provide surge protection for you DAC's and all your other gear so you don't have to worry and more importanly when you get one with isolated outlet banks that filter out the Digital components artifacts on the AC from your Preamp and amp.. this is a huge benifit in sound... I still prefer amps plugged directly into the wall. |
APC recently introduced a series of power conditioners specifically designed for audio/video applications.
Their "S" Type AV Power Conditioner with Battery is pretty much exactly what you are looking for: "Pure sine-wave battery backup, surge protection, isolated noise filtering, and voltage regulation all combine in a single unit to deliver pure, uninterrupted power for high performance AV, home security, and automation systems."
I have been running its little brother - same without the battery back - since November and am very pleased with it. The system sounds very, very good...
http://www.apc.com/products/category.cfm?id=15&segmentID=1 |
I use an APC H15 (non battery backup) in my HT and it works great. It does not limit the current to either mt B&K
receiver or ART of Sound sub. It enhanced the video picture also. With voltage regulation and surge protection, it has been terrific during thunderstorms. I'm looking for another one for my 84 year-old mom's system (Marantz, JBL/w AAD sub) which currently is hooked up the way this post originally stated. Everything is plugged into a Tripplite Isobar which is plugged into an APC UPS with battery backup including the kid's computer. For my analog rig upstairs, I use a Brickwall 2AUD. |
I am thinking about one of the better power conditioner plugged into an APC computer UPS with battery. The battery is only to keep power coming when there is an outage. It's the audiophile grade power conditioner that corrects for problems. What I don't know are: (1) can the conditioner correct for typical square wave generation from the battery; (2) I heard it switches to battery mode during outage, thus is it true that during normal operation the power conditioner would receive fully non-filtered electricity capable of handling things like transient current spike needed for the amplifier. Manufacturers of audiophile grade power conditioners would most likely expect you to plug their equipment directly into a wall outlet, and not through a possibly filtered system like the UPS. So the easiest way to find out would be asking if anybody plug their power conditioner into a computer battery back up and find no degradation in sound. |
If your battery backup system can handle the power-up current draw then you probably can find an acceptable match for your gear. There are a few caveats, but generally once your amp has charged up the banks then it's pretty much your amp's responsibility to provide the required regulated current - that's what those things are designed for.
The suggestion re: APC stuff is something to follow up on, if for no other reason than they usually have decent info on their Web site or linked discussions that can help you figure out what might work and what to avoid. |
What are a few "caveats" you would consider as exceptions to the rule after an amplifier already charged up its banks?
I currently use an old Power Pack II connecting to a 1100VA APC computer grade UPS. There is no way that I can concurrently turn all stereo gears on at the same time; therefore, the APC didn't trip. So then are you saying that there is no current limitation on the amp when music is playing? APC, in their S-type presentation, remarks that transient current need on some amps could be as high as 30A.
I most likely need to upgrade the Power Pack II. Has anybody compare APC S15 to the established audiophile power conditioners? Secondly, does anybody know if there is no power outage, then the computer grade APC UPS simply works in the bypass mode, sending unfiltered electricity into its outlets? It comes across that this square wave problem only play in when the UPS battery must be used. Thank you. |
Please note that the APC unit provides a pure sinewave - as opposed to square wave power. Sinewave is what you need - computers don't care, and it is more expensive to produce sinewave power.
Secondly if you search the Forums you will see that almost all UPS, isolation transformers and the like limit current.
As Mr Hosehead suggests, it may be that once the UPS reaches full charge it will simply pass current straight through - there are only two ways to verify that, either measure it yourself or talk to the manufacturer. Since that would increase the cost and complexity of the unit with no benefits for its target market, my experience suggests that its unlikely.
The one way I know how to do it for sure is to use a 2,000-3,500w sinewave inverter tied to a large 12v battery bank. This type of unit which is designed for off-grid and marine applications, has a very fast switchover from the AC mains to the DC banks. It is also large, heavy and relatively expensive.
Finally I have compared the APC to both Equitech and BPT - the APC product is unique in that it is the only audio/video product that I am aware of that has a battery back-up. (This includes Running Springs, Chang, Gray etc)
Your engineering premise is fine - you just won't find what you are looking for at a low price point. |
What I see from the Forum search is that people attempt to just use the computer UPS as a replacement for a separate power conditioner. That's not what I would like to do.
I'll be curious on what Mr_Hosehead means by these "caveats" must be there in order for an amp to dispense high current spikes. Would an amp be able to help itself for a long enough time thus sustaining such spike before it must be fed by high-current electricity?
Ckorody, would you comment about the additional circuitry complication that APC most likely won't do. Are you saying that there will always be a current limit even when the battery is charged up? In other word, it's cheaper to have the battery acting as a capacitor to the wall outlet voltage, as well as acting as the voltage source to all these outlets connecting to it. Are you saying that circuit design to have the charged battery become an open circuit, thus having to re-route these battery outlets elsewhere when the battery is charged up is more expensive? If so, it's interesting that APC and other computer UPS companies uses terms like "switch over" to the battery when there is an outage. Whereas in reality, the battery, half or fully charged, is always acting as the voltage source to its outlets. Then separately we have the scenario of an aged battery that is never fully charged thus the current leak. |
I am not an EE - most of what I know about this stuff I learned working power issues on my sailboat. Inverters, batteries, alternators and 110. It is an unholy brew.
I understand what you are trying to do. I believe APC has done it for you.
BUT If you would rather roll your own (heck that is half the fun) then I suggest you just hook it up and see what happens.
Your comment that you can't power up your whole system without blowing the UPS suggests that the only thing you can do is to get a much bigger UPS - in the 2-3K watts range as you might find in corporate server environment. Perhaps the larger reserves will also help with any potential current limiting.
Please keep in mind that you are getting into the land of batteries - lots of juice costs lots of money, takes lots of space, maintenance etc. I am looking at the APC site and to get to 3375W they are using 208 in. The unit - without shipping or install is $3,350... Typical back-up time at full load is 6.4 minutes (no typo six point four).
http://www.apc.com/resource/include/techspec_index.cfm
One could come to the conclusion that the reason this product doesn't exist is because there is no real return on investment. Frankly it would be a lot less expensive and considerably more sonically effective to just run a couple of dedicated 20amp lines to your listening area. |
Well, thank you for the comments, but the answer to APC S15 is a no. So far, it does not seem as if anybody had serious comparison between APC and the heavy weight audiophile conditioners such as PS Audio, Audio Power, Shunyata, etc. The existing reviews on the internet tend toward peace of mind and security, as opposed to music quality. Even Stereophile didn't focus on sound performance. Incidentally, security and integrity is what the computer industry expects from surge protector/UPS equipment. So something does not add up. The best I heard was about video quality improvement, and that is not enough a basis to judge music performance, especially when we are talking about upper division stereo separates. APC is well recognized in the computer world. Yet with severely limited review on the audio side, I am not about to spend that kind of money on a rather unknown piece of equipment. |
You know - think this through - nobody makes what you are looking for... |
I just wing it, and got a used Power Wedge 112. Very interesting result! My computer battery is fully charged, or supposedly fully charged. It's definitely better not to plug the Power Wedge into the APC UPS. No I didn't experience any loss of slam in the bass like what others commented. Pluging the 112 directly to a wall outlet just gives more "natural" sound. I don't want to use words like "vividness" or "crisp". There are plenty of CDPs that give you the razor sharp crystal clear sound which can almost kill your ears within 30 minutes. Skipping the UPS gives me a deeper soundstage and more transparent sound. The fog is lifted.
Audio Power did say that the 3 options for the isolated outlets should be experimented. With my equipment, the balanced AC is actually least desirable. The floating output gives the best result. |
Thought I'd breath life into this old thread I came across running a search. I'm researching UPS' as well -- I'm buying a BPT-style balanced power device for my source components and display (the amps and sub will just go into the wall's dedicated lines). I'm also installing a whole-house surge protector. In any case, the outfit building my balanced power device suggested a UPS with voltage regulation and pure sine wave output to go between the wall and the balanced power unit.
It hasn't taken long to figure out that the vast majority of UPS, even the APC Smart UPS unit, don't really have a pure sine wave. Instead, their's is a line-interactive, stepped process, essentially boiling down to it being merely a standy emergency power unit.
My question on UPS' is this. Where do the DUAL-CONVERSION ONLINE ups' fall into the equation? As I understand it, these regenerate power full-time, same concept as the APC S10 or the PS Audio PPP. If I'm not connecting amps and subs to it, should I have any fears of limited current (1000va/700w)?
Thanks!
Aaron |
