Is a high priced Line Conditioner needed

There is only one power conditioner that can really deliver, that won't limit a large power amplifier. It was made by Elgar and was for industrial/commercial purposes, so you have to find one used on ebay, and may have to get it refurbished.

It is mechanically noisy, so you have to place it near the breaker box in your house, and run the wiring from it to your audio room. You might have to have an electrician do the work.

However. It is easily the best made, and the 3006 can deliver a perfect sine wave at full load of 28Amps at 117Volts. Seems to me there is a 1KVa version as well. No noise, no distortion, no spikes. The principle of operation is sophisticated- well beyond what typically passes for 'high end'. It uses an isolation transformer, a precision 60Hz oscillator that is synchronous with the AC line, a power amplifier and a comparator circuit. If the output deviates from the reference oscillator, a feedback signal is created and applied to the feedback winding on the transformer- the result: a low distortion sine wave free of noise.

This is the only conditioner I know of that can handle a set of our MA-2s or MA-3s. Most conditioners I have heard mess things up even when presented with our M-60s as a load, so usually I recommend plugging straight into the wall unless you have an Elgar.

A good power condition can really be a marvelous improvement.

Most of them I have seen in high end audio do more harm than good, unless they are operated well below 50% of their ratings. This is especially true if you have a high power tube amplifier!

I have seen AC conditioners that can run at their full ratings but none of them have been high end audio devices- they have all been commercial/industrial. I find it puzzling that high end audio can't seem to get its act together in this regard!

Here is an example of a conditioner that will knock the socks off of any high end audio unit:

http://www.ebay.com/itm/Elgar-AC-Line-Conditioner-Power-Supply-Unit-6000-Series-6006B-/111408675313?pt=LH_DefaultDomain_0&hash=item19f07979f1

Akg_ca, I don't think I agree entirely with your post. Certainly additional filters can add up to current restrictions. And most high end audio conditioners don't do much more than that.

But the one that I linked to in my earlier post is not a filter and can produce an undistorted sine wave at full capacity (15 amps) without distortion or noise on the AC waveform, and can regulate the line voltage as well.

They made a bigger one that could handle 29 amps at full capacity! They do tend to be mechanically noisy so you usually have to place them near your breaker box, and run the audio room wiring off of the conditioner. But unlike the ones your dealer demonstrated, this kind actually works. The Elgar at the link has not been made in some years, so you have to jump through some hoops to use one, but having seen it first hand I can say its worthwhile. And this is coming from a manufacturer who normally does not recommend power conditioners for precisely the reasons you described.