Simplicity of design. Purity of sound. Introducing Robbie Blues new Class-A discrete tube microphone and instrument preamplifier. All of the technical quality and design innovation that goes into our line of award-winning microphones has been engineered into making Robbie one of the finest tube preamps available today. With no ICs and only the highest- quality discrete components from input to output Robbie is one of the quietest (-131 dB EIN @ 50?) and most detailed (THD 0.006%) tube preamps