Do Specifications Lie? Do Our Ears Lie? Where does the Truth Lie? Interesting New Paper from Benchmark

[alexwgoody]

http://test.benchmarkmedia.com/discuss/sites/default/files/Headphone-Amplifier-Performance-Part-1.pdf

 

I'm still making my way through the paper and will post my thoughts later.

[Paul R]

That came out a couple years ago and sparked hot dispute on some of the more headphone oriented forums.

-Paul

[alexwgoody]

That came out a couple years ago and sparked hot dispute on some of the more headphone oriented forums.

-Paul

 

Really? They just emailed it to me today and said it was new. How bizarre.

[Paul R]

Really? They just emailed it to me today and said it was new. How bizarre.

 

Perhaps I went to the wrong link - the one I hit I believe I remember reading before...

[alexwgoody]

I see the problem. The original paper was from 2011, they updated it today and summarized the updates at this link.

 

Benchmark Media Systems, Inc. - Headphone Amplifiers - Specifications are Only Part of the Story

[esldude]

This is not surprising really. I don't know if headphone amps typically have specs quoted into 100 kohm loads. I know some I have in some low end recording gear aren't. Basically it would be the same as measuring power amps into a 100 kohm load. Load it even with a resistor and it may measure poorly. Which was the case here. Load it with a real headphone which is a bit of a reactive load and it gets even worse. Power amps with speakers would be the same. The Benchmark shows this need not be the case.

 

But all that is going on here is demonstrating that sub-standard designs into basically no load at all (100 kohm load is neglible for a product that could feed something below 100 ohms) may measure fine and choke when asked to power a real load. So headphone amps like power amps need at the very minimum a resistive load for testing that is near what it may see in use.