iBasso D-Zero Mk2 Headphone AMP and USB DAC. The D-Zero is a minimalistic and sleek headphone amplifier and USB DAC. Housed within a beautiful and strong anodized aluminum housing, the unit is clearly made with passion and precision. The front of the device features a headphone jack, an aux jack, a power switch with white LED to let you know when the device is on, and a volume controller. On the back there's a USB output for charging the D-Zero and for connecting it to a computer, a gain switch and a USB charge switch. There's also two LEDs, a red one to indicate charging which also blinks to let you know when to charge it and an orange one to indicate USB connection. So buy this iBasso D-Zero Mk2 Headphone AMP and USB DAC Now £99.00.

Brainwavz AP001 Portable Headphone Amplifier. The Brainwavz AP001 is a ultra portable headphone amplifier that is designed to help deliver more power to your headphones, earphones or other portable speakers than your standard iPod, iPhone, Smartphone or MP3 player. Using an OP Amp the AP001 is able to deliver powerful audio amplification and bass enhancement, without overly colouring or distorting the original audio signal. So buy this Brainwavz AP001 Portable Headphone Amplifier Now £25.00.

Fiio E17K (Alpen 2) Portable Headphone Amplifier with USB DAC. The FiiO E17K is a portable lightweight brushed metal headphone amplifier and digital to analogue converter (DAC). The E17K model is FiiO's replacement of the very popular E17. So buy this Fiio E17K (Alpen 2) Portable Headphone Amplifier with USB DAC Now £99.00.

The NEW FiiO E12A special edition portable headphone amplifier adopts an upgraded high performance OP AMP combination. Designed around the MUSE02 by muses. The audiophile semiconductor division of New Japan Radio Co. Ltd, achieves unparalleled subjective and objective quality coupled with the LME49600 buffer to achieve <0.0003% distortion and increased S/N ration 115dB. The E12A gives the perfect balance between high performance sound fidelity and long lasting durability. The unit gives you low distortion as well as low internal resistance. The E12A has a built in Li-polymer battery with a large capacity, supplying a strong power supply. +11V comes from the three cascaded batteries, while -11V is the outcome of the high performance DC/DC circuit transformation, which in the end creates a 22V working voltage. So buy this Fiio (Mont Blanc) E12A Portable Headphone Amplifier - IEM SPECIAL EDITION Now £129.00.