Do power conditioners help with unwanted hum/noise

Edesilva brings up some valid points, but i'm with Kal on this one. The effectiveness of the power line conditioning in terms of noise & hum will have to do with the source of the noise & hum. If you've got a ground loop, adding a PLC won't do much to cure that. At least, not in most cases. Sean
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I think that we are all in agreement here. That is, even dedicated lines, line conditioning, etc... can't solve a problem that is component or system based. How about describing the problem that you're having? Someone here might be able to point you in the right direction.

Gs: "it's like saying all a wrecked car needs is a coat of wax"

Isn't that like the old saying about a "dog" of a muscle car i.e. "if it don't go, chrome it" : ) Sean
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Tobias: I'm glad to hear of your results. I've been advocating isolation transformers for several years now and have helped others find suitable models for their given installation. Lak and Psychicanimal can testify to the benefits involved and i'm certain that others can too. That is, when the iso's are properly selected and installed. You might want to do some further research on the subject in the archives before investing more money into various iso's as some surely work better than others. Some iso's are more prone to introducing problems into the system, both due to poor design and improper selection for the intended application. Sean
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Edesilva: The "magic box" is basically an impedance compensated isolation transformer and that is why they work as well as they do : ) Sean
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Tobias: You don't need a bucking transformer at all. You can simply use a 220 - 240 volt transformer and separate the legs down to two 110 - 120 volt lines. Personally, i prefer to keep all of the equipment on one leg of the 220 line, but there are those that have split them and never run into problems. Many of these transformers can be run with multiple taps i.e. 110/120, 220/240, etc...

The spec's that you quoted as far as capacitance and "ultra isolation" are right on the money. The only other real factor is current capacity. This would be the rating in KVA's. If you have a 5 KVA ( 5000 watt ) transformer and are running it at 220 volts, you can use ohm's law to tell you how much current it can sustain. Divide 5000 by the input voltage ( 220 or 110, etc... ) and you'll arrive at how much current the transformer can pass. As mentioned in other threads about this topic, i recommend staying below 60% of the rated capacity of the transformer if possible. That is, if your entire system adds up to 2000 watts of draw, you should have a transformer capable of 3 KVA ( 3000 watts ) at the very minimum. A 3.5 KVA unit would be better and closer to the ratio i described. Obviously, a 5 KVA would provide even more headroom with the potential for an even lower noise floor due to less noise induced by the transformer itself.

Hope this helps. Sean
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Warren, i'm sorry if i never got back to you about this subject. I sometimes get plastered with a large quantity of emails at one time. As a result, i sometimes end up losing track of where i left off at or which ones i had enough time to read but not enough time to respond to at the moment. By the time i log back on, more email has shown up and i get lost all over again.

If you would be kind enough to do so, please post your question publicly and i'll do my best to answer it. This may help others to follow along too, reducing some of the emails i may end up getting that ask similar questions. Sean
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Cdc: Each of these are different designs with different outcomes. A choke regulated supply should lower the noise floor and provide less ripple ( voltage fluctuation ). The isolation transformer won't do anything in terms of reducing ripple, but it should lower the noise floor to a measurably greater extent. That is, in terms of how most chokes are used in most power supply designs. Given that i prefer to run the Iso at the breaker box / out of the listening area and the other approach is actually built into the gear, one could actually use both with compounded benefits. Sean
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