Is data hidden or lost?

• a quick note before we get into today's subject. If you are interested in securing a signed copy of my book, 99% True, they are now available. There's only a limited number and I promised I would let you know before they are gone. You can order here while supplies last. The regular editions (at a much lower price) go on sale here on June 4th.

If we know a track of music well enough to use it as a reference we've likely memorized the important qualities like harmonic structure, imaging, tonal characteristics, and inner details. Armed with this information it's then not unreasonable to see how it fairs when amplified by different circuit topologies. One of my favorite tests compares levels of details retrieved. Played through different circuits do I hear the same, more or less detail? Are those details hidden or lost? It may seem picayune to some, but for me, it's an important tool when figuring out what's going on inside a circuit. If the information is still evident but obscured by surrounding tones and colors—clouded as speech gets in a crowded room—I can make one determination of what's going on. This condition might suggest a little better open loop performance would help. Worse is when intricate details are simply missing. In circuit designs, this points us in a completely different direction. We might want to raise the upper-frequency limits or reexamine the input stage to see where the loss occurs. Simple seeming evidence, like data loss or obfuscation, have very different underpinnings pointing designers in completely different directions. Just another example of why it is critical for engineers to listen to their circuits.