What It All Means: line-level preamplifier measurements
Though we sometimes take for granted that the basic "language" of our measurements is clear to all of our readers, letters to the editor tell us that this is not the case. Periodically, then, we will attempt to explain exactly what our measurements are and what they purport to show. Though those with technical training may find our explanations a bit simplistic, they're aimed at the reader who lacks such experience.
Why a Preamp?
That was the question asked by a reader who was perfectly happy with his CD-based system. He was using the gain control provided by the variable output of his CD player and was apparently in no need of phono playback or greater flexibility. He asked us to answer this question, ignoring for the moment the obvious functions of switching, volume and tone control, and phono preamplification. With those hardly trivial qualifiers—and bearing in mind the high output available from many of today's line sources, CD players in particular—do you really need the added expense and complexity of a preamplifier?
Zen & the Art of A/D Conversion
In a series of recent feature articles for Stereophile, Jim Austin has examined how the controversial MQA codec works: "MQA Tested, Part 1," "MQA Tested Part 2: Into the Fold," "MQA Contextualized," "MQA, DRM, and Other Four-Letter Words," and, most recently, "MQA: Aliasing, B-Splines, Centers of Gravity." I doubt there is a Stereophile reader who is unaware of the fracas associated with MQA, and I have been repeatedly criticized on web forums for describing its underlying concept as "elegant."
But elegant it is, I feel.
Zen & The Art of D/A Conversion
It has become accepted lore in audiophile circles that the 44.1kHz sampling rate adopted for Compact Disc is too low. Some writers have argued that, as a 20kHz sinewave will only be sampled about twice per cycle, it will not be reconstructed accurately, if at all.