More examples of 'replacement for its own sake' Lots of audio enthusiasts love changing normal electrolytic decoupling capacitors with expensive audiophile types.. why? I don't now why!! A decoupling capacitor passes unwanted currents to ground away from the signal path. The important function is, to offer a low impedance path for unwanted currents e.g., noise, ripple, and signal bypassing. To effect this, the equivalent series resistance (ESR) and inductance must be as low as possible. A typical good quality low ESR 220uF 100V decoupling capacitor costs less than 30p. A well known audiophile capacitor of the same value and ESR can cost several pounds! The difference audibly... there isn't any! Those nasty ceramic capacitors we hear audiophiles ripping out of circuit and replacing by foil ones are superior for HF decoupling due to their inherently low inductance. You often see these sensibly shunting decoupling electrolytics to improve HF and spike suppression. Speaker cable Solid state amplifiers have a very low output impedance relative to the speaker impedance. The output acts as a voltage source. Therefore, short lengths of thick twin copper wire to each speaker will make the best use of the amplifier's excellent damping factor. Valve amplifiers have much higher output impedance than solid state amplifiers, so the effect of the speaker cable resistance is much less pronounced. In both cases, ordinary multi-strand thick twin flex is perfectly suited. Don't spend £100s on speaker cables. The important parameters of a speaker cable are as follows: • A relatively low series resistance compared to the speaker DC resistance to maximize efficiency (i.e. several hundred times less across the cable length). (The difference in resistivity between copper wire and silver wire is not at all relevant at the lengths used. If a 3mm square section copper cable was 1km long it would have a resistance of 1.86 ohms or 3.7 ohms for twin runs. The same length solid silver twin run would have a resistance of 3.53 ohms. Thick multi-strand copper wire is perfect. Don't waste your money on silver or silver plated wire) * • Low inter-cable capacitance and therefore high capacitive reactance across the audio spectrum, relative to the loudspeaker impedance. (The inter-cable capacitance of decent low cost twin flex has a capacitive reactance way above that of the speaker impedance across the audio spectrum, so it is irrelevant) • Low series inductive reactance relative to the nominal speaker impedance across the audio spectrum. ( ordinary thick multi-strand loudspeaker twin flex has a negligible inductive reactivity at audio frequencies To achieve the best performance use inexpensive 80 to 200 multi-strand twin (figure of eight) cable and keep the length as short as possible ( i.e., a few metres). 80 strand 0.2mm twin speaker cable is typically around £1.20 per metre! * From Pouillet's law: R = p x l /A 'R' is the resistance in ohms. 'p' is the resistivity of the metal used (copper 1.68 x 10-8) (silver 1.59 x 10-8) 'l' is the length of the cable in metres 'A' is the x section area of the cable in metres