"High Current"

Jeffreybehr: As discussed in another relatively recent thread, power ratings can be manipulated by the manufacturer. Even if they are rated to "double down", most amps DO NOT really do this, the ratings are just "fudged" to look good to the consumer. That is why i specifically stated "power at clipping" as it is a much more thorough, grueling and revealing test. With this type of testing, the amp either does or doesn't "double down". There is NO guessing involved, regardless of factory ratings at various impedances. Unfortunately, very few reviews actually perform or publish this type of testing, so getting good information becomes harder when trying to make an informed decision. Sean
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Sean,

I'm surprised by your comment:

Unfortunately, very few reviews actually perform or publish this type of testing

for this is certainly something that Atkinson at Stereophile does regularly test and publish.

Regards,

Metralla: The audio world does not revolve around Stereophile alone in terms of equipment reviews. How many other reviews / reviewers do this? That was the point that i was trying to make. Having said that, i'm glad that Stereophile does perform such tests and it is one of the reasons that i still subscribe. Sean
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Sean...This issue of measuring power "at" clipping is new to me. I usually see specs quoted at some specified level of distortion (presumably an acceptable level). But isn't it true that distortion typically begins to increase abruptly just before clipping, and the manufacturer takes the power value just before this happens? I suggest that power measurements at the two points will differ only slightly.

As an aside, how do you deal with an amp that doesn't clip, because it has clip limiting. In that case I think you will just see increasing distortion as the signal peaks are rounded off.

All of this comes back to how the manufacturer wants to market the product and how the marketing department thinks will be the most effective manner at achieving those goals.

Given that i've seen amps rated at 200 wpc @ 8 ohms clip at 280 wpc, there's obviously some discrepancy and sometimes sizeable differences between ratings and reality. Given that the same amp was rated at 400 wpc @ 4 ohms and clipped at 418 wpc may shed some light on the subject.

While some might say that the manufacturer was just being "conservative" with their 8 ohm rating, others might say that the "doubling down" figure of 200 / 400 looked more impressive to the audiophile than a 250 / 400 rating. This is especially true since we are only talking about a percentage of one dB in rated power @ 8 ohms.

I think that a common question / statement in this type of situation, and one that i've seen here on Agon before is, "How much more would an extra 50 wpc get you when you've already got 200 wpc to start with?". Given the average audiophile's way of thinking, and this was already expressed in this thread above, isn't it easy to see why the manufacturer would "lie" about how powerful the amp is?

By down-grading the power rating of the amp by a "mere" 50 wpc, they can now pick up the "prestige factor" and "reputation" of building a "beast of an amp" that "doubles down". If it actually DID double down as impedance was halved at clipping, we would know for certain that it IS a beast of an amp with a very ample power supply and output stage. Seeing that it actually doesn't come close to doing that at clipping tells us that it isn't nearly as "beefy" as they want us to believe.

This is called marketing and it is pretty much what high end is all about. The more successful marketing is, the more product that they can sell and the more they can charge. The approach that i'm talking about removes the gloss of marketing and allows one to see the actual build quality of the entire product at a glance, hence the "newness" of a rating like this to you. They don't want you to know the truth about their product, they want you to be fooled by the hype. Sean
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