*Please note -- this item is pre-owned and may show signs of use. Includes a six-month Alto Music warranty. 

The Fredenstein F660 Limiting Amplifier is a valve (tube) based compressor and limiter with the same very short signal path as the famous Fairchild 660/670. It uses the exact type of tube, the 6386 LGP, as the Fairchild. Fortunately, new production tubes are available today, since the original tubes are hardly available anymore. The four tubes form a single-stage push-pull Class A amplifier and the whole signal path consists only of a T-type input attenuator, input transformer, Class A amplifier, and finally an output transformer. At this point, the similarities end. The F660 uses a DSP to control the operating points of the tubes, guaranteeing perfect working conditions all the time. The side chain amplifier is designed with semi-conductor components since it “only” generates the control voltage for the tubes. The final result is a compressor with the compression characteristics of the Fairchild, but with an extended frequency response, lower noise and lower distortion. The perfect bus compressor is for today's high-resolution audio.