D-Sonic peak current output compared to other

This is a video explaining why current output is so important in audio playback:
http://www.youtube.com/watch?v=Y_22XOakyxM&feature=player_embedded

Not sure I buy the explanation in the video. It needs elaboration to know what he is trying to say.

The exert below is very clear and it is consistent with basic electronics course content.

This is an exert from The Complete Guide to High-End Audio as published for free by The Absolute Sound at AVguide.com

This link has the free download guide to electronics 2012. The section of this exert is on page 13.

http://media.avguide.com/BG_Audio_Electronics_2012.pdf

"
Excerpted and adapted from The Complete
Guide to High-End Audio (fourth edition).
Copyright © 1994–2012 by Robert Harley.

Why Amplifier Output Current Matters

Some amplifiers barely increase their output
power when driving 4 ohms; others can double
it. This means that not all “100Wpc” amplifiers
are created equal. One “100Wpc” amplifier
might put out 150W into 2 ohms, while another
might deliver 400Wpc into 2 ohms. This ability
to drive low-impedance loads (specifically, to
deliver lots of current) has a large influence on an
amplifier’s sound and subjective power capability.
Loudspeakers have dips in their impedances at
certain frequencies, which puts greater currentdelivery
demands on the power amplifier.

This difference has real-world consequences.
The ability to increase output power into low
impedances indicates how much current the
amplifier can deliver to the loudspeaker. It is
current flow through the loudspeakers’ voice
coils (in dynamic loudspeakers) that creates the
electromagnetic force that causes the cones
and domes to move, and thus produce sound. If
current flow through the voice coil is constrained,
so is the music.

An analog is helpful to understanding this
concept. Think of a power amplifier driving a
loudspeaker as a water faucet and a hose; the
water pressure is voltage, the flow of water through
the hose is electrical current, and squeezing the
hose forms a resistance (impedance) to the flow.
In this analogy, the loudspeaker’s impedance is
the resistance in the hose that impedes the flow
of water. The lower the loudspeaker’s impedance,
the less the resistance to current flow from the
amplifier, and the harder the amplifier must
work to deliver current to the loudspeaker. If the
impedance is halved (say, from 8 ohms to 4 ohms),
the amplifier is asked to deliver double the current
to the loudspeaker (all other factors being equal).

If the amplifier isn’t up to the job, the musical
result is strain or even distortion on musical
peaks, weak bass, loss of dynamics, hardening
of timbre, and a collapsing soundstage. In short,
we can hear the amplifier give up as it runs out
of power. Conversely, amplifiers that can continue
increasing their output power as the impedance
drops generally have very deep, extended, and
powerful bass, virtually unlimited dynamics, a
sense of ease and grace during musical peaks,
and the ability to maintain correct timbre and
soundstaging, even during loud passages. If you
have relatively high-impedance loudspeakers
with no severe impedance dips, you’re much less
likely to encounter sonic problems, even with
modest power amplifiers; the loudspeaker simply
demands less current from the power amplifier.

Amplifiers with high current capability (indicated
by their ability to increase output power into low
impedances) are often large and expensive. Their
current capability comes from massive power
transformers, huge power supplies, and lots of
output transistors—all expensive items.

Keep in mind, however, that not all systems
require large power amplifiers. If you have sensitive
loudspeakers with a fairly high impedance, the
loudspeaker’s current demands are vastly lower.
Consequently, smaller amplifiers work just fine.
Single-ended triode amplifiers with as little as
3Wpc and very limited ability to deliver current
can sound highly musical when driving a load-appropriate
loudspeaker.

Excerpted and adapted from The Complete
Guide to High-End Audio (fourth edition).
Copyright © 1994–2012 by Robert Harley.
"

There are a number of things in the excerpt above that are patently false (despite the source) but are indeed widely-held opinion in the form of myth.

For example the ability to play deep effortless bass has nothing at all to do with the ability of the amplifier to double its power as impedance is halved.

If you would like an example of this, try that of a Sound Lab ESL being driven by a transistor amplifier. The tendency is for the amp to be bass-shy on that speaker while also being too bright.

What in fact is far more important is the relationship between the amp and speaker, as well as the intention of the designer of the speaker. Very closely related to this fact is the experience of seeing 'good' specs on paper, but also knowing full well that the specs will not tell you how that amp will sound in your system.

Here is an easy to read article about what is going on:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

Most box speakers have a woofer in that box that makes the bass. The woofer has a resonance in that box that is expressed by a peak in the impedance curve. This usually shows up in most designs right near the low frequency cutoff of the speaker itself. So you can see that the comment:

amplifiers that can continue increasing their output power as the impedance drops generally have very deep, extended, and powerful bass

is not really true at all. In fact making deep bass has nothing to do with 'tons of current', since at the resonant peak in the box, the speaker's impedance will be high, not low, forcing the amp to make *less* power, not more! Obviously something else is at play in the way amps make good bass.

It is true that lots of capacity in the power supply (which is the source of the 'amplifier' current that generated this thread) is generally associated with the better amplifiers made. But it is the relationship between the amp and the speaker that actually governs the things we hear from them. Understanding that fact is how you avoid flushing large amounts of dollars down the loo.

Whatever Robert Harley said is his experience, which becomes statistical fact. Others can agree with him or not based on their own experience, which can be totally different.

I don't think there is actually a "myth" related to the importance of current in amplifier design. The proof of that is there are actually very few amp specs (tube or solid state) that actually mention the current output. "Watts" is the myth here, I think.

Magnepan thinks amp current output is important in the context of their speakers. I would think they actually have experimented with their speakers mated with all kinds of amps to come to this conclusion.

It is impossible to come to a consensus as every designer's opinion is biased based the intricacies of their designs. Hence, what Parasound said is true and what Atma Sphere said is also true.

At the end is the music that matters. Your amps sound great, so do Parasound amps and many other amps out there with totally different designs.