Audio engineers and producers searching for a reference-quality microphone preamp with an ultrawide bandwidth, extremely low noise floor, impressive distortion specs, and a remarkable impulse response will be impressed with the Fredenstein HD Reference, a fantastic two-channel microphone preamplifer. Its unique topology features a true Class-A design, zero negative feedback, and a 100% balanced circuit with 72 premium transistors for gain, as well as a ±24V power supply.
The preamplifier provides extremely low noise and low distortion with an ultrawide frequency response (1 Hz to 920 kHz, -3 dB) at all gain settings. The preamp sports a combination of high-end specifications to provide a smooth transition into saturation. This is due to the absence of negative feedback and the fast recovery inherent in the topology, which allows the sound to go from pristine and three-dimensional through rich and powerful depending on how hard one drives it.
Each channel features a combination rotary encoder that doubles as a push-button mute and gain control with 1 dB stepped operation from 0 to +64 dB (using highly reliable relays). A large 7-segment LED display indicates signal levels and clipping. There are three impedance settings, three high-pass filter frequencies, 48V phantom power, and a polarity switch.
Other notable features include automatic muting when changing phantom power settings to prevent damage to your monitors, and a pair of high-quality Direct Inputs (DI) for use with instruments.
The HD Reference is compatible with the separately sold Commander remote, which allows you to keep the preamp close to the microphone, while being able to make adjustments in the control room. By keeping the mic cables short, the preamp is able to preserve the fragile mic-level signals without degradation or noise and send a robust line-level signal to any reasonably distanced converter, console, or compressor. There is a Lock button, which prevents the HD Reference settings from changing when using the Commander remote.
Low-Cut 82 Hz: A 82 Hz low-cut filter is activated when lit, avoiding unwanted low frequencies while tracking.
The gain range for the DI is from 0 to +40. Turning the Gain knob past +40 will have no effect. When a 1/4" plug is inserted into the DI jack, the HD Reference automatically switches on the DI preamplifier and lights up a LED at the bottom right of the Gain display. If a separately available Commander is used, it will also use that LED to display that the DI is plugged in.