Fredenstein HD-REFERENCE 2-Channel Microphone Preamp

The Fredenstein HD Reference Stereo Microphone Preamp stands out as a groundbreaking design renowned for its exceptional performance among mic preamps. Based on the acclaimed topology of the 500 Series Fredenstein HD PRE, which employs a current mode, true Class A, zero negative feedback, and fully balanced circuit with 54 discrete premium transistors, the HD Reference elevates this with 72 transistors and a +/- 24 volt power supply. It offers precise 1 dB gain steps displayed on its front panel.

Technical specifications highlight its extreme performance: ultra-low noise (EIN - XX dB), minimal distortion (.XX% at 60 dB gain), wide bandwidth (-3 dB at 900 kHz), and capable of delivering +30 dBu at the outputs. Unlike typical tube preamps, it excels in smooth saturation transitions, leveraging its feedback-free design for fast recovery and dynamic range.

Features include stepped gain from 0 dB to +64 dB via high reliability relays and a large 7-segment LED display, along with three high-pass filter frequencies, three impedance settings, phantom power, and polarity switching. Automatic muting during phantom power changes prevents thumps and monitor damage. Additionally, dual Direct Inputs cater to instruments with low-noise discrete JFET inputs (2 megohm) offering 0 to 40 dB of gain.

When paired with the Fredenstein COMMANDER Remote Control, users benefit from keeping the mic pre close to the source while controlling all HD Reference features. This setup preserves mic-level signals over short distances, transmitting robust line-level signals to converters, consoles, or compressors via standard mic cables. The COMMANDER includes a LOCK button for preventing unauthorized adjustments at the remote preamp, ensuring reliable operation in professional environments.

Fredenstein HD-REFERENCE Includes:

• 1 x Fredenstein HD Reference Stereo Microphone Preamp
• 1 x Operating Manual
• 1 Year Warranty

Fredenstein HD-REFERENCE Features:

• 2-Channel microphone preamp with 64dB of gain
• Fully discrete signal path and Class A balanced output stage
• Current amplification circuit eliminates internal transistor capacitance
• Experience warm, natural sound through zero-negative-feedback topology
• Transformerless design won't color your sound
• Digital displays allow you to set your gain level in accurate 1dB steps – great for setting up stereo pairs
• 7-Segment LED meters make monitoring your levels easy
• 3 Impedance settings optimize the preamp for your microphone
• 3 Highpass filter frequencies eliminate unwanted low-frequency rumble
• Phantom power and polarity reversal
• Discrete JFET inputs for your guitars and other high-impedance sources
• Optional HD Commander remote control for keeping the preamp close to your mic (sold separately)

Fredenstein HD-REFERENCE Specifications:

• Frequency Response: 2 Hz – 700,000 Hz, - 1 dB, 1 Hz – 920,000 Hz, - 3 dB
• Distortion: < 0.0082 at +4 dBu Output Level (31 dB Gain)
• Input Noise (EIN): < -128.5 dB (150 Ohms Source Impedance 64db Gain),
• Input Impedance: > 200 k Ohms or 1000 or 300 Ohms Selectable
• CMRR: > 60 dB at 54 dB Gain
• DI Impedance: > 2 M Ohms
• Max. Input Level: + 20 dBu
• Output Impedance: 600 Ohms Max.
• Output Level: + 30dBu
• Max Input Signal: +20 dBu
• DI or Microphone Input: + 0dBu
• Rack Units: 1 RU
• Dimensions: 19 x 1.8" / 48.2 x 4.4 cm