Where to learn about bypass capacitors?

Can anyone point me to a source of information about the use of bypass capacitors, mainly in source gear? I'm beginning to have an understanding on their use in crossovers.

Basically, what gear benefits from the bypasses, and how to visually I.D. which caps to bypass?
It depends upon what you mean by "bypass" capacitors. I'm going to assume that you are referring to the practice of using smaller value caps in parallel with larger ones rather than the "decoupling" definition. The smaller value bypass capacitors are better (faster) at higher frequencies.

For example, a 2uF coupling cap might be bypassed with a parallel .01uF cap. The overall capacitance change is negligible, but the sonic benefit at high frequencies can be significant. Large power supply electrolytic capacitors are typically bypassed with smaller value film caps to nullify the negative sonic aspects of electrolytic type caps.

One of the advantages of bypassing is that the smaller value film and foil caps can be much less expensive than the equivalent brand/type in a larger value. Bypassing makes the sound quality more closely resemble the better smaller cap- especially at the more critical higher frequencies.

Some purists do not believe in bypassing, choosing instead to employ a sufficiently high quality single cap of the correct value. They argue that time smear and incoherence is caused by bypassing with smaller value faster caps.
Be sure the cap you are adding(in parallel) has a voltage rating at least as high as the original cap.

If theres room you could solder aligaror clips to a bypass caps leads and easily A/B test its effects.

Do be careful of the charge that a cap can hold after the power has been shut.

John C.