A custom audio amp is a high-end, often hand-built, amplifier with a unique combination of features tailored to a specific user or purpose. Examples include the Custom Audio Amplifiers (CAA) OD-100, a channel-switching tube amp known for clean, crunch, and lead tones, and custom mixer-amplifiers for PA systems. The term can also refer to modern, high-power amplifiers that can be configured with specific components, like a high-current switch mode power supply.