Atmasphere use teflon film and foil capacitors to couple one stage to another where it is necessary to block DC. Typically they use the VCap brand, which at least for the hobbyist like me are among the most expensive. And coupling capacitors are the most critical in the signal path. In general, teflon film and foil capacitors are most expensive, made by VCap (or whoever makes them for "VCap"), Solens, and RELcap, so far as I know. There’s also Mundorf film and foil using various kinds of foil. Metallized film capacitors can sometimes be excellent although few of them are high in cost. Dynamicap, Auricap,etc., are good brands. REL are always decent. I also like polystyrene film and foil capacitors but they seem to be nearly out of production in high voltage ratings. REL makes them too. You can get them with 100V ratings and maybe a bit higher for solid state applications. Texas Instruments "nude" bulk foil resistors (TX2575) are very transparent and cost about $12 and up, each. Dueland resistors are even much more expensive but so large as to be useful mostly in speaker crossovers. Also excellent and cheaper than TX are Caddock TF020, sold by M Percy, and tantalum resistors, probably in that order of excellence. You want the best possible resistor in phono loading and at the interface between stages. These are brands to look for in tube gear. In SS gear, which is nearly always on a PCB, you will find SMDs (Surface Mount Devices). These are tiny resistors/capacitors, and their use minimizes inductance in the circuit, because there is practically no space between them. I’m sure I am missing some pointers here. In my experience, using good parts, that may or may not be "expensive", is more important than, for example, tube rolling. For one thing, tubes age and change inevitably over time. A good film cap is nearly forever, unless it sees a voltage much higher than its rating, which only happens if some other part goes bad. Resistors are less profound, except as phono load resistance.