Power Supplies
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2752 Registered: Dec-06 | Wouldn't it be better to use a battery instead of a transformer from 120v 60hz AC to power an amplifier? A good auto battery seems to be good for amplifier power...? |
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Gold Member Username: NuckPost Number: 9520 Registered: Dec-04 | Andre, the incoming power goes directly to the XO of the device, distributing various voltages and ampacity to various places. While dc sources are used frequently in pre-amps and phono stages, the current demands and availability of amps for this stuff is in a Civic. I like Opus the penguin on the tuba. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11906 Registered: May-04 | . How do you plan on telling the amplifier it will now be seeing 12VDC rather than 120VAC? Or are you going to let it be a surprise? Assuming you have this figured out, how do you intend to maintain a constant 12VDC while the system is operating? Whajja gonna do about the off gassing of hazardous fumes from the automobile battery? Andre, where do you come up with these ideas? It's good that you think about things but you don't seem to draw logical conclusions or work from a well established base of information. Is this car battery supposed to power the 4000 watt amplifier in your future system? . |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2753 Registered: Dec-06 | Umm, my thoughts were you wouldn't have a transformer and all the associated problems if you just supplied the DC with batteries. Couldn't you just put together a cheap and effective exhaust system to channel it off? It seems you could design your own amplifier and use a battery for power? It seems like it wouldn't be a huge challenge to design a regulation circuit to keep the voltage from changing. You could always add more batteries in parallel to lower their internal resistance to minimize voltage drop. I meant it for something more like 50w... Whatever..lol |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11908 Registered: May-04 | . There are small, high quality amplifiers which can run on batteries. Stress the word "small". The class T amplifier I have is using a 12VDC SLA battery for it's power. You're correct it does eliminate some problems associated with AC operation. It is impractical for most high power applications since the transformer is seldom the issue in power amplifiers other than for shipping costs - which will likely increase if you're supplying a car battery and its attendant parts with your design. The rest of the power supply after the rectifier circuitry will remain largely the same with the cost remaining essentially the same as for an AC powered amplifier. DC storage caps are going to cost the same no matter where the DC comes from. AC ripple and noise are eliminated by battery power but the batteries required for home audio are typically best left to low power consumption devices such as portables, class T amplifiers and pre amplifiers. One notable phono pre amp uses 16 "D" batteries for its power supply. AC ripple and induced noise from line problems are non-existent in this sort of arrangement. High current delivery is not a possibility with most battery operated power devices which eliminates a lot of contemporary speakers from the choise list. Not an entirely bad idea but one that will not go down easy. A "cheap and effective exhaust system to channel it off" probably isn't a good idea since the EPA would have mulitple problems with the gasses or possible leakage of hazardous materials and the necessary exhaust system and any fan noise will obscure any noise benefits you might achieve with your batteries in place. How much space do you think the numerous batteries and exhaust system would require compared to a simple AC transformer? Add in your regulator - which will require a transformer 'cause you're going to have to get your power from somewhere and it will very probably be the AC wall outlet - and I think you might want think through this problem again. Add in the line noise generated by the regulator when the system draws large amounts of current and the problem becomes self evident and why no one uses this sort of system for home audio power amplifiers becomes clear. Keep thinking, Andre. But consider reality every now and again. . |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2756 Registered: Dec-06 | Ah, well. That's true, you have to consider all the factors. You know how they sacrifice efficiency for fidelity in speakers sometimes? Could you not vary the width of the magnetic gap to create a linear BL factor and lower distortion? It would be hard to do that, though. They vary coil density in some designs. Hmm.. |
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Bronze Member Username: MagfanUSA Post Number: 69 Registered: Oct-07 | Use optima deep cycle marine batteries. do not run the charger while running the system. disconnect the charger when running the system. Andre, don't let ANYONE tell you something can't be done. When most 'experts' agree something is completely, 100% impossible, you can bet it IS possible. 5x12v in series will give you better than 60v to the rails with zero ripple. You will need a high current regulator to tone it down a bit. Really, why not? Use sealed batteries and forget the fumes. No Smoking! Some of the single driver speakers ($$$$) have a magnetic gap of over 1 Tesla....strong enough?? |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2758 Registered: Dec-06 | Well, yeah, that was the point. I now see that they do use it in amplifiers, just not to the same degree. Don't think I just skimmed over that without reading that. I did. That is quite strong, definitely. Another thing you could do is use a computer controlled electromagnetic motor that cancels all non-linearities in flux as the coil moves back and forth within the field. Hmm, I wonder if you'd be able to to control inductance variation to an extent in the voice coil. At least BL could be perfect. Then there would be Cms to deal with. Maybe something could be controlled there as well. There are a lot of factors involved, like the enclosure and room. Eh, I don't know. It seems a bit hard to and quite complex. We have speakers that work with electromagnetic fields, and then there are the ones that work on other properties. Arrrr Oops, I think I've left the topic of power supplies. Pfffftttt |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11914 Registered: May-04 | . I don't think anyone would say Andre's basic idea is "impossible"; just impractical as stated. How much space will be devoted to the 5X12VDC batteries? To gain what benefit that can't be achieved by a more consistent method of AC power treatment? Which doesn't present problems of ever decreasing current availability not present in an AC voltage input with a simple transformer? You can connect a floating charger but that's still more stuff to deal with. You can run everything in class D like a car stereo but then you get car stereo sound quality. What level of performance does this fit in? Naim tried this years ago and never brought a viable product to market. Rowland Research has explored battery power over the years but, to my knowledge, have also never produced a viable product beyond a battery powered pre amplifier. It's a great idea; the silence from my class T, battery powered, six watt amplifier is somewhat spooky. Paired with high senstivity speakers it's a sound that easily gets your attention for what's not present. Possibly as the class D&T/ICE technologies improve, improved battery technology will eventually replace AC lines. However, I think we're still a long way from batteries being the norm in home audio. For one thing, people are too tied to unrealistic speakers for such an amplifier. . |
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Bronze Member Username: MagfanUSA Post Number: 70 Registered: Oct-07 | Jan, thanks for your considered answer. Battery storage? No problem. look at the mess many of the hard-core audiophiles have stacked up behind and between there speakers. A battery box would not be a big hassle, by comparison. You could conceal it as a planter. BelCanto and PSAudio both use the ICE amps and NOBODY has accused them of 'car sound'. Indeed, the HCA-2 (Tripath based, methinks) was a Stereophile 'A' piece. PSAudio's GCC series get jam-up reviews. The GCC 500 is probably the most powerful Integrated available. 60amp/hours at 60 volts+ is 3600 watt hours+ with an average draw of say.......100 watts that gives you 36 hours and 45watts/channel at 90%...perhaps a little hi estimate. Hypex and ColdAmp are both in contention and have a rabid DIY following.... A pure DC supply to your amp would be a great theoretical goal. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11920 Registered: May-04 | . As a planter?! You're right, LS, if an audiophile has it, they want it to be seen. Disguising audio as anything other than audio is a sure path to failure. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11921 Registered: May-04 | . The BelCanto and the PS Audio are decent sounding amplifiers. At the present time, they operate on AC direct from the wall outlet so I wouldn't even begin to expect "car stereo" sound from these amplifiers. They use conventional power supplies and operate in the 10% efficiency range. To successfully do battery operation the efficiency apparently must be upped to the 80-90% efficiency range. So there's a long way to go before we let loose of that AC tether cord. PS Audio offers line conditioners which are meant to address the quality issues of AC line voltage. Seems they are wedded to AC voltage and rectifiers for quite a while also. Batteries are a worthy goal but they are not quite ready to make the elap to home audio, IMO. Battery technology is getting a fresh look lately so there is hope. The real question, for me at least, is why did we ever decide AC was the best choise when so many things operate on DC? I know the answer but that has always been a good question. Sort of like why did we ever decide to run our cars and industries on dead dinosaurs. . |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2759 Registered: Dec-06 | I have a question. Would it be better to use three-phase AC to power amplifiers than single-phase? I think you could get a more consistent DC |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11923 Registered: May-04 | . If you really want that 4,000 watt amplifier, you might look into that, Andre. Of course, once again you're going to have to explain to the amplifier why it's receiving three phase input. Otherwise, it's a waste of money. |
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Bronze Member Username: MagfanUSA Post Number: 71 Registered: Oct-07 | Yep, stuff must be visible. A couple racks of batteries, charger and associated gear is just the ticket. The PSAudio power plants are basically high power audio amps....that put out 60hz. They operate at fairly low efficiency. Other class 'd' folks use SMPS which are more efficient. |
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Bronze Member Username: MagfanUSA Post Number: 75 Registered: Oct-07 | Jan, Batteries are indeed 'coming on strong'....The new chemistries like LiIon and NMh are real contenders. No need to put up w/lead-acid and Hydrogen fumes, which are quite dangerous. BOOM. As for why we use AC, just ask Tesla. DC is not feasible for distribution networks of more than a few hundred yards. Consulting the patents for the original 'polyphase' system and the induction motor shows the AC system clearly superior. You're right about the planter, however! If you got it, flaunt it. Just another point against Bose and those alledged speakers. You answered this question long ago with some comments about the tube/SS debate. It is just plain easier to ship SS gear. Now imagine shipping an amp with 100lb of battery in tow. People who prefer tubes also end up paying a shipping premium for handling and weight. I believe the inefficient numbers quoted for the BelCanto and PSAudio amps are related to the Powersupply only. The driver/output stages are of fairly hi efficiency and will be in the hi-80s or better at 100% output. Many reviews of this equipment comment on the cool running properties. All current BelCanto equipment is issued in the same size enclosure. Even the 1kilowatt monobloc. The case is about 1/2 rack width and only 75mm tall. An AB amp of these dimensions and output, if even possible, would have to be cooled by Liquid Nitrogen....another asphyxiation hazard. In conclusion: Most people would frown at car stuff in the home. True. But the car designers are leading the way to better power utilization. It is not out of bounds to think that eventually some of this technology will filter into your home theater or stereo. Imagine, a HT receiver you can't cook on. |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2770 Registered: Dec-06 | Aww, then I'll have to buy a real stove.  |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 11950 Registered: May-04 | . I an unfamiliar with the current PS Audio and Bel Canto line ups. Are all their power amplifiers now class D? I know Rowland has one class D amp in their line up but the other four (?) are typical class AB designs. Do these amps run off a switch mode supply or a conventional ps? I thought a few of the Bel Canto designs were using the Tripath chip only as a driver stage feeding a class AB discrete output stage. . |
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Bronze Member Username: MagfanUSA Post Number: 77 Registered: Oct-07 | Jan, The BelCanto lineup includes a 100/200 @8/4 ohm mono and a stereo version. also an Integrated of same output. they call it 150/300, but @10% distortion for short time periods. I'll go with the lower number, since this is the 200???module from B&O. the Integrated has a USB digital input, which I suspect near future-proofs this stuff. They also have a 500/1000 monobloc ALSO using the big B&O module. This one gets bangup reviews, but name your reviewer and poison..... All the BelCanto stuff uses the SAME CASE size which probably saves 'em bunches of money. The stereo basic amp also has balanced/unbalanced inputs and a biamp switch which puts the left channel input to BOTH channels. Can you make it any easier to Bi-Amp? (i'm tempted) The PS Audio stuff also uses the B&O modules exclusively. The GCC integrateds are of particular interest to me, in the name of 'component matching', since you already know i run a bastardized NAD/ROtel system..... They go 100/200 or 250/500 or 500/1000 (YIKES) at 8/4 and also get good reviews. The PS Audio HCA-2 (Sterophile 'A' list) was a tripath based unit, and has been dropped but not forgotten. This amp was dropped by a reviewer in mid-review when the GCC / GCA series came out. These 2 manufacturers distinguish themselves by detail treatment to essentially the same modules and are said to have slightly different sounds. On this, you'd be a better judge than I. There are some in-the-case photos on the net and you can't see a big toroid at all. My guess is the SMPS operating at 400khz or so..... From our 'for what it's worth' department. Stereophile LIKES the GCC 100 and puts it on the 'A' list. Read there review if you have time. Reviews? Name your poison. I don't see many or any 'pan' reviews printed. Bad for advertising, I suspect. I think a review of reviewers is in order,so you can begin to tell real from fake. When I look at movie reviews, I never fail to look at WHO it is I am reading. Some reviewers I can clock and trust......others are gibberish and don't have a pattern relative to my likes/dislikes. My advice (also for what it's worth) is to get to know reviewers and how they relate to what YOU do and don't like, so you can kind of get a handle on there reviews....If they love it, you either strongly suspect it is true (subject to your personal review) or know they are full of it and wouldn't trust 'em with knife and a jar of peanut butter. Before I go shopping, I try to get a handle on stuff....anything I am in the market for from tires to photo gear. Finding a review AND a store you can trust are critical to me. Then the tough part is making up your mind! |
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Bronze Member Username: MagfanUSA Post Number: 78 Registered: Oct-07 | http://www.stereophile.com/integratedamps/106ps/ Link to Stereophile review of GCC 100, |
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Silver Member Username: MagfanUSA Post Number: 103 Registered: Oct-07 | Link to amp with battery driven outputs. There is a used one on Audiogon which has a price of nearly 10,000Euros. This works out to over 12 large and would be a dent in any but the most ambitious wallet. http://www.stereophile.com/integratedamps/1006asr/index.html So, Andre, in answer to your question....Yes, it is possible, but why? |
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Gold Member Username: NuckPost Number: 9680 Registered: Dec-04 | Just ain't giving up eh, Leo? Good link, thanks |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2799 Registered: Dec-06 | Eh.. Batteries are practical for portable apps, of course. SQ is usually sub-par in a lot of situations, though. |
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Silver Member Username: HuronPost Number: 354 Registered: Mar-07 | andre what happened to creating the worlds baddest sub woofer? anyways interesting thread but cant AC be conditioned enough to eqaul the battery thingy that your talking about? Im just poping in to couse trouble and to show off my bad spellingg |
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Gold Member Username: NuckPost Number: 9684 Registered: Dec-04 | The spelling part worked. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 12139 Registered: May-04 | . "Conditioning" the AC is not as easy as it sounds and certainly not inexpensive in practice. Whatever you place in line to perform the clean up will cause problems of its own. Transformers and capacitors are the most common devices used to "smooth" the noise from the AC line by creating a buffer between the outlet and the component piece. Both devices cause phase problems in the AC Voltage and therefore cause lead/lag problems between current and Voltage when the amplifier attempts to draw large amounts of "power" through the supply line. Capacitors can only recharge at a specified rate which means the amplifier might drain the reserves of the conditioner with one large burst of power. Typically, very large multi-capacitor reservoirs are installed after the components that perform the "cleaning" of the AC components. These reservoirs don't need to be very large for most source components such as a CD player but beyond that in the system, the amount of reserve on tap increases dramatically and so does the cost and size. So the answer to the question is the same as always. Yes, it can be done if you are willing to invest the time and money required to properly do the job. The same could be said for battery supplies. If I show you one advantage with this approach or that component, I'll probably take away two you could gain from the alternative. I don't know why but that still almost always seems to be true. . |
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Silver Member Username: HuronPost Number: 355 Registered: Mar-07 | thanks jan, I recently bought a power conditioner and a ups for my porjector look at my profile and see what you think, I will do research on the subject when I have the time, I new capacitors and transformers are a part of it and I new the lag issues, but thank for the great explaining, Im not an expert and my schooling in electonics was a long time ago, wouldnt the cycles of ac be an issue? |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 12143 Registered: May-04 | . "wouldnt the cycles of ac be an issue?" I can't think of why. The line conditioner doesn't attempt to alter the frequency of the incoming AC with any sort of step down/up transformer. Maybe I'm not understanding your question. . |
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Silver Member Username: MagfanUSA Post Number: 104 Registered: Oct-07 | In the link above, I also looked at the photos. There were NO torroids in evidence. A fine example of the give / take of real design considerations. In a cost-no-object piece, you'd think they could use the finest transformers available....and they chose NOT to use torroids. just a thought about 'are torroids really best?' While it is true that every design approach has its good/bad points, sometimes the the bad points have nothing to do with sound...or the easy, 'good' way, either. |
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Silver Member Username: HuronPost Number: 356 Registered: Mar-07 | sorry jan but I wasnt talking about the conditioner I was talking about andres thread in genral, this is stuff I never thaught about, using batteries over ac in our homes for amps or other things, then leo hear starts talking all this stuff and showing products, In reality isnt it getting the purest you can get but at a heffty price? and what I was getting at with the ac cycles is the ripples after the conversion, yes I know a good bridge rectifier and capacitors and maybe a voltage regulator but I will leave that stuff to the manufacture, I gess I should ask how much is there to gain with the battery thang? jan thanks for your post 12139 I read it a few times |
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Silver Member Username: HuronPost Number: 357 Registered: Mar-07 | nuck what is opus penguin on the tuba |
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Silver Member Username: MagfanUSA Post Number: 106 Registered: Oct-07 | Angelo, For 99.9% of all audiophiles, AC vs Battery will make no discernable difference. For the cost-no-object, lunatic fringe who simply must have bragging rights AND have near-limitless deep pocket funds available, an amp like the ASR Emitter II Exclusive at (GASP!) 25,000$ will probably about do it. Just imagine the look on your friends faces when you shut down the stereo and drag out the 'ole Sears Craftsman Battery Charger...... 'Funs over for tonight, boys. Gotta charge the Amp!' |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 12158 Registered: May-04 | . al - Read Post Number: 11908, posted on Sunday, December 30, 2007 - 02:08 pm above. See if that doesn't answer your question. And, really, 12139 wasn't all that special. You shoulda caught number 477! Whoowhooooo!!!! |
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Silver Member Username: HuronPost Number: 358 Registered: Mar-07 | your right about batteries getting better fast but you didnt mention Li-Po batteries thats used in RC like my little walkera 4#3  there are some people around were I live that invested in solar because there to far away for power, the solar panels charge batteries I would have to do research but dont thoughs systems run both ac and dc? |
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Silver Member Username: HuronPost Number: 359 Registered: Mar-07 | yeah I read that one jan very nice, In your 914 when you mention how your class T amp is some what spooky, is that some experiment of yours? leo Im looking at that amp right now and, WoW |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 12160 Registered: May-04 | . Just a project, al. The batteries make for one quiet amplifier. |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2805 Registered: Dec-06 | hmm interesting Angelo, I'm working on laying out the plans for the sub system. I'm also getting my resources lined up so I can fly through it when the time comes. It all has to be just right. Anything else I would have said has been covered. |
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