...nobody seems to pay attention to.

Miller capacitance of transistor amplifiers is about 10-15 times that of valve amplifiers at higher frequencies. Simply put, Miller capacitance is the lag between line input and amp output. Transistors, therefore, lag in treble and even high midrange, compared to valves. Wonder why guitar players prefer valve amps? They've better contour and presence. Transistor amps are more neurotic/inaccurate in treble.

Copper has higher capacitance at higher frequencies than silver. Even though it is not by as much, it adds up to the rest of lag to make a serious difference in dynamics. Wonder why silver wiring is better? There's why.

Different types of capacitors have different sonic transparency. Again, this is because of lag at higher frequencies. Polypropylene, teflon, and silver mica are the most audio-friendly. Capacitors, especially electrolytic, can also have lag in high frequencies due to increasing resistance: this distortion type is called ESR - equivalent series resistance. Cheap electrolytics are the worst in terms of ESR - some are so bad, they audibly lowpass at 3 KHz.

Overall, the audio electronic engineers' fixation with numbers and frequency response is something of a bugger, if only because they forget about dynamics and accuracy in the time domain. A playback device is so much better when it responds quickly - even if in measured terms a treble delay introduced by combined HF lag of transistors, copper, and barmy capacitors and resistors might be something like 1-4 msec., it's usually enough to make or break liveliness and realism.

You have no rights to post comments