for AC power bottle head cord or better a Topaz isolator
for DC power to a USB DAC, use an isolator/regen device and a LPS for best results (which may be zero depending on your DAC etc.) - wind up a DC cord using a star-quad layout or buy from Ghent
for speakers, use short runs with mono-blocks and try various cheap cables until you like the effects of complex impedance changes
for ICs, use balanced
all the above are inexpensive and effective - shills, fan-boys and fraudsters will try to sell you ineffective things for thousands
for DC power to a USB DAC, use an isolator/regen device and a LPS for best results (which may be zero depending on your DAC etc.) - wind up a DC cord using a star-quad layout or buy from Ghent
for speakers, use short runs with mono-blocks and try various cheap cables until you like the effects of complex impedance changes
for ICs, use balanced
all the above are inexpensive and effective - shills, fan-boys and fraudsters will try to sell you ineffective things for thousands