The AudioQuest DragonFly Black is the best DAC under the $100 budget, and in price, the DAC will give you tremendously enhanced sound. It is a lower power consumption DAC and works fine with Apple and Android phones, tablets, etc. The brand HIDIZS is also manufacturing portable plug-and-play DAC amps under a $100 budget, and for Ultra-low-power dissipation, you find HIDIZS Dac is best.