Myths...
Good amplifiers still benefit from power conditioners. The difference is in the conditioner. The real problem is that when your sound improves in many ways, it shows you the lack in others. When you AB, if you can hear the difference right away, it's often that the music isn't as full, you might call it "dynamics" or a host of other things depending on your ear. But what's happened in many cases is that the refinement has reduced the bloat of poor information that was perceived as part of the music before.
When you're at that point, the type of resistors in key places, capacitors, circuit topology, it all starts to play a bigger role because the differences become more notable.
This is fundamentally obvious given that entirely passive parallel filtration will do this just like series active filtration will. Essentially many power conditioners take the blame for the let downs in your equipment. But I will say there's a fair amount of crap out there that's been sold as a power conditioner. The giant chokes by Gray did work, but no one ended up liking the sound, the resistance was through the roof too so they wasted a ton of energy, and his pricing may not have been very appropriate.
This all seems ridiculous to me since a system with a good power conditioner is a pleasure to listen too, and one without is a chore by comparison.
Also to note, almost no amplifier has any serious filtration to speak of. The design usually rejects a fair amount of RF and ground loops, but even very well designed units benefit from power conditioning.
Sorry but I am not able to understand the point being made here. However I will qualify a few things that I know.
1, The Gray choke that I measured drew 6 mA from the wall. That is nothing, but then it did nothing, because it couldn't at that small current. If they "wasted a ton of energy" they would run very hot and the one I measured was stone cold. I doubt anyone would put up with a hot conditioner.
2. Any "passive parallel filtration" would have to fight the low impedance of the power line and would lose that battle.
3. I don't believe any filter can do squat against ground loops. The only way to solve ground loop problems is to break them with ground floats or go balanced as we do in the RM-200.
This I disagree with emphatically... """Also to note, almost no amplifier has any serious filtration to speak of. The design usually rejects a fair amount of RF and ground loops, but even very well designed units benefit from power conditioning""".
The truth is that the power transformer presents more leakage reactance (a good thing) than the chokes in power conditioners and 1000 uF of filter capacitance is a lot bigger than a the few tenths of uF that most line conditioners have. For the uninitiated, a line filter typically provides series inductance and parallel capacitance to filter out the high frequency noise on the line. However the values of these are much larger
inside the amplifier than values that could be placed
outside the amplifier. If these values were used outside the amplifier the parallel elements would draw serious current while the series elements would add to the primary resistance of the transformer and impede it's regulation.
The power transformer in an RM-9 or RM-200 is on the order of 1 ohm. I am proud to say that is very low. Now add in the power cord resistance (here is a slight positive for heavy power cords). However a 6 foot 18 ga power cord is only 0.072 ohms and a 15 ga cord is half that (good rule to know is that every 3 gauges is half or twice the resistance depending on which way you go). So either way we haven't added much yet. Enter the power conditioner boys. They wind chokes that go in series with the line. What is the resistance of those? They are typically wound with several feet of 18-15 gauge wire. There usually several on both sides of the line (2 minimum). Perhaps they add more than the power cord. This is why I don't recommend them period.
I cannot speak for other designers but all my amps and preamps have excellent RF filtering as any good engineer would do. All of my customers that I have spoken with have felt relieved to hear that I suggested they dispense with power conditioners.
