Carry it in your pocket.

At less than 1/2 inch thick, the UHA-4 is our slimmest amplifier. The low-profile controls make it easy to tuck the amp into a pocket and take it along. The internal rechargeable battery provides up to 24 hours of amplification using the line input. With USB connected, you can charge the battery and listen to music simultaneously, either from USB or the line input.

Stay centered.

Unlike analog volume potentiometers, which can sound unbalanced at some settings, the UHA-4’s digitally-controlled volume maintains precise matching between the left and right channels. It uses a series of discrete resistors to keep the image stable and centered at any volume setting. With 2-dB steps and two levels of gain control, you are guaranteed smooth and accurate volume adjustments at any gain level.

Change your soundstage.

In a natural acoustic environment, low-frequency sounds are able to diffract (or “bend”) around the head, and we end up hearing those sounds with both ears. Not so with headphones — a low-frequency sound in one channel is only heard by the corresponding ear. With some recordings, this can create an unnatural experience, causing fatigue over time. The UHA-4 includes a crossfeed feature which allows you to blend some of the low-frequency sound from each channel into the opposite ear, creating a more natural soundstage.

iOS

Supports analog connection from headphone output or line out dock (LOD) to line input.

Android

Supports analog connection from headphone output to line input.

Mac

Supports USB digital interface with sample rates up to 48kHz/16-bit using built-in operating system drivers (USB Audio Class 1.0).

Windows

Supports USB digital interface with sample rates up to 48kHz/16-bit using built-in operating system drivers (USB Audio Class 1.0).