• API's Classic 312 Microphone Preamp in a 500 Series module
• Vintage Style Analog VU Meter
• Maximum 69dB of gain
• Traditional API fully discrete circuit design with 2520 OP-amp
• Proprietary AP2516 Input Transformer
• 20 dB pad switch
• 3:1 Output Transformer Tap Selection
• Switchable 48V phantom power
• Peak LED
• API's Five Year Warranty

https://www.apiaudio.com/product.php?id=158

인풋 트랜스포머(API2622, API2516) + API2520 OP-amp + 출력 트랜스포머(API2503)