BuyDig cut its price on the FiiO E6 Portable Headphone Amplifier (pictured) to $18 with free shipping. That's $1 under our mention from a month ago and the lowest total price we've seen. (It's a current price low for this model by $7.) It's designed for high impedance and low sensitivity headphones.

Also available is the FiiO E10 USB DAC Headphone Amplifier for $49 with free shipping. That's a buck under our July mention and another all-time price low. (It's a current price low by $13.) It has an all- aluminum Shell and enhanced anti-interference ability.