4 channel zero distortion preamp

The ZDT preamplifier series is based on discrete circuitry designed by David Blackmer, establishing a new standard of sonic excellence in electronics. This exacting new standard provides frequency response from 1Hz to 200kHz +0.5dB, a rise time of 0.27 microseconds and distortion of less than 1 part per million (0.0001%), eliminating all possibility of sonic degradation. These preamps are so fast, so clean and so transparent that you don’t even know they are there. It is like plugging your microphone into a “piece of wire with gain”. You will hear clarity and detail with the ZDT preamps that is not available in any other preamp at any price.

    • • Zero Distortion – less than one part per million
    • High output level +33dBu
    • Very Low Output Impedance will drive long lines without interference or signal loss
    • True 48 volt phantom, polarity reverse & clip indicator
    • Separate XLR & 1/4” Phone (t-r-s) outputs, each with its own gain/level controls
    • 1/4” Phone connector output will drive balanced or unbalanced inputs
    • Lowest Noise of any preamp on the market
    • Full Differential (balanced) from XLR in to XLR out – no internal conversion to single-ended
    • All Discrete Components; Class A Amplification (No ICs in the signal path)
    • Greater Transparency with minimum signal path and minimum features


Specs :

Preamp Type: Solid State

Number of Channels: 4

Frequency Response: 2Hz to 100kHz ±0.1dB, 1Hz to 200kHz ±0.5dB

Impulse Response: 1.4µs

Distortion: XLR out: less than 1ppm (0.0001%); 1/4” out: 0.001%

Input Noise: 1.6nVHz½ at 20dB gain; 0.6nV/Hz½ at 60dB gain

EIN: -132dBV at 20dB gain; -143dBV at 60dB gain

Slew Rate: 22V/µs

Output DC Offset: ±1 mV typical, servo balanced

Power Requirement: 120V AC (100V and 200-240V versions available)

Input: 4 XLR Female balanced transformerless

Input Impedance: 10KΩ phantom on, 100KΩ phantom off

Outputs: 4 XLR Male balanced transformerless (stepped)
4 ¼” TRS XLR Fem. balanced transformerless (variable)

Dimensions: 1 rack space 1.75” x 19” x 10.375”

Weight: 6 lb. (2.7kg)


Earthworks 1024 Preamp  Earthworks 1024 Preamp rear