There are only two things that don't affect the sound of an audio system: the brand of batteries in the remote control and whether or not you're wearing a digital watch, but I'm not sure about the latter.
This statement may be truer than you suspect. I have found very little that did not matter including: wire, fuses, chassis, resistors, capacitors, feet, vibrations, ad nauseam (from the Latin term to drone on until the point of vomiting, but let's not go there).
The tiny bits we call surface mount parts now populate nearly everything electronic including modern digital audio equipment. We're the better for their use in one area, worse in others. Without surface mount parts, digital noise would overwhelm our music in ways we would not appreciate. Yet running decoded analog through them may not sound as natural as the live music we hold as our reference.
To address the performance difference between resistor types we choose the appropriate style for each application. For example, the analog path of a PerfectWave DAC is built from expensive through hole types, the digital constructed from surface mount; each choice made with purity as its goal, and there are many other examples as well.
The choices we designers make when conceptualizing the types of materials music must pass through on its way to your loudspeakers are many. They are made with the understanding that it all matters.
