JDK R20是一款十分细致和构造坚固的双通道话筒前置放大器。是全部由API设计团队设计的。R20拥有低噪音性能。并且有高质量的话筒和内部电源的机架底盘乐器的输入。上架式机箱内有内部电源。每个通道包括可旋转增益控制和独立拨动开关，控制幻象电源、相位、衰减器和话筒＼乐器输入选择。每个前端面板上的高阻抗乐器输入能提供最高为31dB的增益。每个通道的衰减器开关能把话筒输入信号减弱-20dB，把乐器输入信号减弱-10dB。

Features:

• Dual Mic Preamplifiers with 54 dB of gain
• Custom analog VU meters for monitoring output level
• Front panel, high-impedance instrument input with 45 dB of gain
• Peak indicator
• Pad switch attenuates the microphone signal by 20 dB, or the instrument signal by 10 dB
• Switchable 48v Phantom power
• Low distortion, low noise circuitry
• Fully balanced output, both 1/4" and XLR