Power line conditioner cuts high frequency ?

The DC power supply in your amp also filters out high frequencies....that's its purpose.

The AC fed to your power supply is filtered, removing all 'frequencies', resulting in flat line DC. This DC is then modulated by the power transistors, producting an AC waveform.
It doesn't matter what a "power conditioner" does to the incoming AC, it'll be converted to DC anyway.

A power "conditioner" won't change the frequency response of your system.

To make the above comment more complete, a power conditioner won't change how your system sounds at all. If one is needed, all it will do is make the input ac of your system more stable, but there are internal circuits that convert the input to dc, then to ac through a chopper circuit, which outputs a higher hz ac for use with a smaller transformer. However, during the dc stage the power supply can be used to deal with most fluctuations, as such, most fluctuations get filtered before the dc is converted back to ac, giving the system better ac to use than the input ac. Simply adding a power conditioner will only make the input ac more clean, though, unless you were experiencing fluctuations so great that the device was having trouble operating, i don't think you would need a power conditioner.
However, ignoring that, a power conditioner cannot affect the output audio of the amp, let alone its frequency response, which is modulated by the input signal.

This is called a switched mode power supply, common in PC's not so common in linear amplifiers.


No, the point of the SMPS is to provide low voltage high current, efficiently. The Chopped DC is rectified and filtered back to DC....high frequency AC is pretty useless, unless you're making a plasma lamp. BTW, the chopped DC looks much much worse the the incoming sine wave....certainly not better.


If your AC fluctuates to the point where the equipment doesn't work properly, you have much bigger problems then a "power conditioner" can cope with. Also, if it doesn't contain motor driven variacs, how does a "power conditioner" regulate voltage?

Unless there's something really wrong with your amplifier -- either a bad power supply, or a really bad design. There are some guitar amps (especially tube amps) that do not properly filter out AC noise. In those cases, things like balanced power or power conditioners actually will help.

If there is an actual difference in sound (and not just a placebo effect), then one or two things are true:
1) There's a design problem or wear-out problem with your amp.
2) You were so used to the noise from the power lines that the removal of that noise (leaving only intended signal) actually startles you.

However, for 2) to be true, 1) pretty much needs to be true anyway.

Oh, ok, what is the name of the type that is used commonly in linear amps?


My understanding is that you would rectify the ac to dc, then chop the dc to create ac again (though possibly a bit messier ac), but at a higher hz, then run this through a transformer to lower its voltage, then rectify it to dc for use. This way, with the higher hz ac you could use a much smaller transformer to step down the voltage (as lowering voltage at the ac stage through inductance is more efficient than other means with dc). Or is this incorrect?

Does it suppress surges as well?

Most power amps are linear, and most use conventional line-frequency power supplies. And an increasing number use switch-mode power supplies, as more designers gain competence with that technology.

A small fraction of power amps are non-linear--e.g., class D. Some use a conventional supply, but probably most of them now use switch-mode supplies. If you can design class D well, then it's not too much of a stretch to understand switching supplies.

typically a linear supply, a transformer, rectifier and capacitor.


Yes, that's what I said.

Non-industrial mains voltage regulators often use tapped autoformers, with control circuitry that automatically selects appropriate taps that will maintain the output voltage within the desired range.

Such a supply is not linear at all, whether it is a switch-mode or a line-frequency conventional type.

There are many misnomers in electronics....just read these forums for a good example.
I wonder why the transformer, rectifier, capacitor combination is called a linear supply?


http://en.wikipedia.org/wiki/Power_supply

Ok, i was just confused why you stated "high frequency AC is pretty useless, unless you're making a plasma lamp" when in fact the high frequency ac, in my post, was to increase the emf to then use a smaller transformer... so it is then in fact not "useless."

How does frequency increase "the emf"?
The high frequency allows the use of a physically smaller transformer, physically smaller and lower capacitance capacitors, and finer regulation.
In your post you stopped after the chopper circuit, there was no final rectifier or filter that why I mentioned that high frequency AC is pretty useless...what uses high frequency AC?

I guess i figured you'd assume it would be rectified...
And the universal emf equation provides proof of the increase in emf with frequency.


Which allows the core flux density to be less for the same voltage, preventing saturation from happening sooner.

Only if all parameters are held constant and frequency is changed....and, of course, this is for sinusoidal waveforms only...so it doesn't really apply to the chopped waveforms present in SMPS.

I guesss I figured you'd understand the equation you posted.

No need to be rude, my comment was a fair one, as it could very well have been assumed that the ac would be rectified.
And the resulting signal is still close enough to sinusoidal (if the chopper circuit contains a pulse width modulator) to at the very least loosely match the equation. I'm no mathematician so i was not able to provide an exact equation for the purpose.
But, obviously it still applies, even loosely, as the outcome is as it predicts. Even if the other variables are not held constant, an increase in frequency does increase electromotive force, assuming of course you don't intentionally alter the other variables to make it not... but that is true for any equation.

Take your own advice, I responded in kind.


I'm guessing you've never seen this on a 'scope, if you think it's a sine.


Not according to the equation you posted....or the other laws of physics.

I was never rude to you, and if it seemed that way, you've misunderstood.


The problem with the turn this discussion has taken is that, from what i can tell, there are a ton of different chopper circuit designs. As such, its hard to tell which we are referring to. I know you can get "simulated" sine wave depending on your inverter design. As such, i said "close", which of course is dependent on your own personal definition of close.


Well, then the design of many switch mode power supplies defy the laws of physics. From your own link:
"High frequency and high voltages in this first stage permit much smaller step down transformers than are in a linear power supply."
Higher frequencies cause an increase in the emf to achieve less flux density for the same voltage, again, preventing the saturation from being reached as soon. This either allows an increase in capacity or a reduction in size.

When you figure out what this means, come back and we'll discuss it like two educated adults.


If you say so.

I'm at a loss if i am incorrect. Looking around i found another wikipedia page on transformers specifically, and it states:
"The EMF of a transformer at a given flux density increases with frequency.[12] By operating at higher frequencies, transformers can be physically more compact because a given core is able to transfer more power without reaching saturation, and fewer turns are needed to achieve the same impedance."
Which unless i am misunderstanding something confirms what i thought.
The wiki page

Can't think of any reason why a power conditioner should change the FR of the system.

If the power line conditioner removed "buzz" then the rest of what you hear may be due to your general perceptions being altered by the removal of the buzz.

It's well known that different parts of the audible spectrum change our perceptions of other parts of the spectrum. For example, raising the bass will tend to make most people more receptive to a raised treble.

OK. I could believe this..the dynamics part, anyway. I experienced the same phenomena, but I was running four pretty good sized power amps (1,230W total output) from one filtered power strip.

I noticed the deficiency in dynamics only when using most of the amplifer's potential. No noticable problems with it at low to moderate levels for me.

My solution was to put the amps directly to the wall on a dedicated circuit.

zeiter, basically your power conditioner provides surge protection and AC noise filtering. What it does not do, as apparently assumed by all, is regenerate new, clean AC. For that you're looking at over ten times what you paid for your Panamax, for example PS Audio's Power Plant Premier.

Your description of constricted dynamics and muffled/veiled sound almost exactly parallels my experience with entry-level conditioners. Plan on spending $500 and up for a conditioner that doesn't degrade (or actually improve) your sound. Even then, most conditioners, including yours (sorry!), can't provide enough combined steady-state and peak current demanded by many power amplifiers such as yours.

It appears your salesman, cognizant of your equipment and AC quality, sold you a conditioner inadequate for your needs. Or he sold you an inadequate conditioner without knowledge of your equipment and AC quality. Either way, if I were you I'd get a refund and go elsewhere. And don't let anyone tell you that a-v equipment doesn't benefit from voltage regulation, especially if your AC is crummy.

Trust your own ears. Buy what sounds best that you can afford.