Fredenstein HD Reference 2-Channel Microphone Preamp

HD Reference

The HD REFERENCE Microphone Preamplifier can be described as unique, revolutionary, and among the best performing mic pre's of all time.
Well almost unique. The internal topology was first introduced in the 500 Series Fredenstein HD PRE which features the new current mode, true class A, zero negative feedback, 100% balanced circuit that uses 54 discrete premium transistors for gain. The HD REFERENCE goes a step further with 72 transistors and a +/- 24 volt power supply. The HD REFERENCE is also designed to be remote controlled (or not) and offers 1 dB gain steps shown clearly on the front panel.

Technical performance can only be described as extreme or exceptional. Extreme low noise (EIN - XX dB), exceptional low distortion (.XX% at 60 dB of gain), extreme bandwidth (-3dB down at 900kHz) and is can deliver +30 dbu at the outputs. And while it sports the holy grail, grand combination of high end specifications, The HD REFERENCE also out-performs typical tube pre-amplifiers in the area of smooth transition into saturation, due to the absence of negative feedback and the fast recovery inherent in the topology. In other words, it goes from pristene to 3 dimensional through rich and then power house depending on how hard one drives it.

Features include 1 dB stepped gain from 0 dB to +64 dB (using high reliability relays) indicated with a large 7 segment LED display. 3 high pass filter frequencies, 3 impedance settings, phantom power and polarity switching. Details like, automatic muting while phantom power is changing, to prevent thumps and damage to monitors is built in. There are also a pair of Direct Inputs for instruments with low noise discrete JFET inputs (2 meg ohm) and 0 to 40 dB of gain.