Pure Power

For those of you who are looking for AC power that is already clean to start with, instead of trying to clean it up, I have found somthing you may want to try. I have been using it for some time now, and it is very good. I use a Studer(Revox) Pure-Sine power inverter to create my own 120VAC power from a battery bank of 12vdc Trojan T105 golf cart batteries. It creates a pure, clean 120VAC 60Hz sine wave output that is fully regulated to within 5% and has less than .05% distortion at rated power. It is totally quiet, both audibly and electrically. For those on street mains power, a suitable inexpensive battery charger can be used to charge the batteries out of your wall socket during periods of non-use of the system. Turn off the charger during the playing of your audio system to avoid noise from the charger. I can turn my system up full, and put my ear to my 100db speakers and hear NOTHING. It's black.(Except on phono input, where I hear the tubes because of high gain.) You have to get a suitably sized battery bank and inverter to meet your system's power requirements and desired run-time. I have a 400 watt inverter and 880 amp/hour battery bank, and I can run mine all evening with no problems, but my system only pulls about 100 watts. Owners of large watt Class A systems will need much more battery and inverter capacity. The Studer line of inverters covers output wattages in different models from 200watts to 2000 watts-continuous. Someone who wants to use 2000 watts continuous will need alot of batteries. However, this is a way to get clean power from batteries, without modifying your equipment. You eliminate all sources of interference, including the stuff in your house, like the refrigerator and the low voltage lighting, etc. It has absolutely no common connection to the audio system at all. My 400 watt Studer inverter will run about a 100w amp, a typical preamp, a CD player, turntable, tuner, or (separately) most TV's and possibly a small HT setup. Anything under 400 watts total. If you need more, then simply get a higher power inverter. My 400 watt unit cost abut $450. My batteries cost about $400. A charger is about $50. If you want to, Studer offers the same inverters with a solar charging circuit, to allow you to hook solar panels directly to it, and charge the batteries by the sun. The 2000 watt unit is around $2k. So for an expenditure of about $900 minimum(for a smaller system like mine) you can get total purity of power. This is less than a single high end power cord from some companies. And this power will be better than you can get from the street mains, with ANY KIND of power cord or conditioner, no matter how much you spend. The absolute finest power cord and line conditioner money can buy cannot equal this setup. I used a hospital grade receptacle for the output of the inverter, and my regular audiophile-quality power cords to plug into it. For those who want the best, and have some room for battery bank storage, this is the way. And, as an added benefit, it is cheaper than many "power scrubbers" that cost more, but are not as good. I am using this, so I do not overstate or have a lack of understanding of the real-world characteristics of using a system like this. I live with it every day, and listen to it every night. BTW, you won't believe how your TV picture looks with a rig like this to provide ultra-pure power to it. These units are Swiss-made to the most exacting standards. The quality is up to the best of any of your audio components. The batteries are the industry standard for golf cart deep-cycle severe duty. This setup has been tested over the long term by me, and I can recommend its use without reservation. It is NOT a half-baked theory. If you are using any 12vdc operated preamps, or directly heating your tube filaments with 12vdc, you can tap the dc directly off the same battery bank to run your 12vdc stuff. I do this with my filaments and TT motor. My amp is all 12vdc operated triode ZOTL. My CD player and the high voltage in my preamp is run off the Studer Inverter AC supply. Also, my TV is too. When listening upstairs, I use the Studer to power my Armstrong 626 reciever (40 watts) to very good effect. If you need 240VAC for your rewired componets like amps, you can use a toroidal autoformer to step-up the voltage for you. Trace Engineering makes a 2kva or 4kva one that is very good for this use. I'm just sharing this as an option for you to get the right kind of clean power, without spending a ton of money to clean up the dirty junk that comes from the street, that never gets really clean anyway. Another cool thing is, that if the street power ever goes out, you can still listen to your system, watch TV, or run a few lights and appliances off of your battery powered auxiliary AC supply. Try it, you'll like it.
While i have a great amount of respect for the engineering capabilities and products of Studer / ReVox, i have yet to see an inverter that did not produce a GOB of interference. Nor have the ones that i've looked at produced a very "clean" sine wave i.e. distortion was noticeable. Having said that, i've often wondered what running directly off of batteries ( no inverter ) would do. I'm sure that it would be quite fabulous sounding.

I do have a 2000 watt inverter that i recently purchased. It is still sitting in the box. Mind you, it is probably not of the build quality of a Studer / ReVox, but it is probably the sturdiest "bang for the buck" unit that i could find. The fact that it set me back next to nothing was how i ended up with it in the first place.

The other alternative would be to set-up a small yet powerful generating system. This would not be hard to do and is something that i may consider doing once i relocate. Sean
Sean, as I previously stated the interference is non-existant. You are probably referring to the cheaper modified sine wave units that are popular for campers. This is a "perfect sine-wave" device, with the characteristics described above. I have used modified sine-wave units in the past, and they definitely put out some big time noise. This is a complete departure from that type. It is clean, clean, clean. I don't even have a single line scrubber on my power line or any shielding on my IC's. My sonic background is totally black. ZERO noise on the line stage with the volume up high and my ear right next to 100db/efficient speakers. I don't think that it can get any quieter than dead quiet. I had to check to see if the power was actually on, because it was so dead that it seemed like it was not turned on! It was only when I switched to the phono stage that I actually heard the higher gain output of the phono tubes as some hiss. I have over 65db gain on that tube phono section. Take my word for it, it's quiet. And as far as headroom goes, it can slew up to 800 watts for up to 30 seconds in demand-surge conditions. I do use the straight DC battery power as much as possible, but for the CD player and TV and certain other items, this is impossible. As such I have used, and recommended this Studer inverter as a very good AC power source. And for those who cannot use DC power on their gear, it is a good way to get real clean power. If the powerline was great, we wouldn't have a raft of power conditioning products to add to our systems. I'd be willing to put the unfettered output of this inverter up against anybody's wall socket output and see which has more grunge.
How long does the charge last? How many charge/discharges can the batteries handle? Both ideas are very interesting.
Unsound, that would depend on the batteries and amount of draw upon them. The use of deep cycle batteries would allow longer than normal use without the need for charging quite as frequently. Then again, batteries of high surge capabilities ( such as those used in electric golf carts ) could provide slightly greater instantaneous power on demand. Just as selecting hi-fi gear can be as easy or difficult as you make it, so can selecting a battery : ) Sean
You can determine the run time by multiplying the amps drawn by your equipment, times the number of hours you want to run. This will give your amp/hours, which is how deep cycle batteries are rated. If you don't know how to calculate the current draw of your equipment, divide watts by 120(or 240 depending) and you get amps.You shouldn't run the batteries below half charge, if you want to maximize their lifetime, so get twice as much amp/hour capacity as your calculations suggest. The Trojan T105 batteries are 6 volt heavy duty type, so you need a pair of them to make a 12 volt battery. One pair of T105's will give 220 amp hours at 12 volts. Since your current draw will be at 120 volts, the current draw on the battery bank will be 10 times that much. If you draw 1 amp at 120v from your inverter, your batteries will have to provide 10 amps of 12v current to the inverter to meet the demand. This is why we locate the inverter near the batteries, and run a dedicated circuit to the audio system. It keeps the 12v battery cables short, since they have to handle 10 times the current draw. Better to make the long runs with the higher voltage. As a typical rule of thumb, a pair of T105's will give you 10 amps for an hour at 120VAC, and still retain about 50% of their charge. So, if you need 10 amps/120VAC for 3 hours of listening, you need at least 6 T105's. 8 would be better, since there are inefficiencies that I've not calculated in this example. 8 T105's cost about $400-$450. With the proper inverter, they will provide 1200 watts of power for 3 hours a night, still retaining 50% of charge. If you maintain them, they should last at least 3-5 years at a 50% discharge rate.
You must use very short, heavy cables from the battery bank to the inverter. In the above example, where the inverter is providing 1200 watts, the battery cables will be carrying 100 amps. Too small cables will get you a fire. Also, you must install a DC disconnect(fuse) of a proper rating in-line with the battery cable, because of a possible short. The battery bank can dump enough instantaneous current to arc weld. Common sense prevails.
Can a trolling motor and stereo be run off the deep cycle batteries at the same time? Any suggestions for some bass-kicking tunes? Sorry, .....

Off track again, I attended my parents 60th wedding anniversary this weekend. Some of us tried to guess how many make it this long. We figured about 1%.

Find this group really humorous and interesting.