NAD PP4Digitise your vinyl collection Offering superb measured and sonic performance, NADs two simple solutions, the PP 4 Digital Phono USB Preamplifier makes it easy to add phono to many of todays stereo amplifiers and AV receivers that have either eliminated the phono input or included a low quality circuit for attaching your turntable. As part of NADs commitment to the environment, the PP 4 features a more efficient green power supply that reduces power