Harmonic Integrity
Current Testing
Testing of amplifiers has changed very little over the decades of
existance. The current tests which measure the
"quality" of audio circuits (THD, Frequency Response,
noise) has proven to be of little information as to indicating
the sound of an amplifier. One of the reasons for this is due to
the simple waveforms utilized by measurement instrumentation. In
fact, most tests are done with a single sine wave. One thing that
we know about music is that it is never made up of a single sine
wave!
We have spent a lot of time developing methods to determine the quality of an amplifier's ability to pass a complex waveform. One of the things we have learned about distortion measurements has to do with the nature of music and sounds.
Musical
Signals
Music and natural sounds have a characteristic that higher
frequencies components have lower amplitude. When these smaller
higher frequencies are mixed with larger lower frequencies, a
slight distortion of the larger frequency can completely change
the character of the high frequency signal.
For example, if 10 Volts at 60 Hz were mixed with .1V at 3kHz, and the 60 Hz signal had 1% distortion (or a .1 volt distortion component). Then the distortion from the 60 Hz signal would be as large as the 3 kHz waveform! This can completely change the audible character of the 3 kHz waveform.
It would be unrealistic to try to make a distortionless amplifier so we used another approach. We aimed to ensure that distortion components did not affect the sound of the smaller signals. This is a difficult task, and requires a lot of knowledge about how the ear "hears". Only listening will determine how well we have done. We feel that we have done a tremendous job!
Michael Yee
Audio
101 E. Alma St. #301
Mount Shasta, CA 96067
PH: (530) 926-4844
F: (530) 926-4808
email: mikeyee@michaelyeeaudio.com