500 Series Zero Distortion Technology™ Preamplifier
Based on the Earthworks ZDT Zero Distortion Preamplifiers™ technology designed by David Blackmer, the 521 brings the exacting standards of the Earthworks Zero Distortion Technology preamplifiers to the convenient 500 series format.
The solid state 521 features switchable phantom power, polarity invert, and peak amplitude clip detection, just as in the original 1021 single channel ZDT Preamp. The transformerless output stage of 521 ZDT easily drive long cable runs without loss of quality, making it ideal for long cable runs. Transparent gain is switchable from 5dB to 60dB in 5dB steps.
The Earthworks microphone preamplifier topology provides outstanding common mode rejection, excellent overload margin and an incredibly low noise floor, combined with the ultra wide bandwidth of the ZDT Preamps and distortion of less than 1 part per million. This exceptional level of performance is maintained over an extensive range of impedances applied to the input making the 521 suitable for practically any microphone – ribbon, dynamic or condenser.
Zero Distortion – less than one part per million
Switchable 48V phantom power
Polarity invert switch
Peak amplitude clip detection
Transparent gain switchable from 5dB to 60dB in 5dB steps
Ultra-low noise floor
Suitable for most ribbon, dynamic or condenser microphones
Preamp Type: Solid State
Number of Channels: 1
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
Input / Output Connector: 500 Series EDAC Edge connector
XLR Input Impedance: 10KΩ phantom on, 100KΩ phantom off
Front Panel Balanced Out: ¼” TRS XLR Fem. balanced transformerless (variable)
Dimensions: 1 500 series rack space 1.5” x 5.25” x 6”
Weight: 0.8 lb. (0.36kg)
The ZDT preamps are very transparent, like the preamps are not even in the chain, and let the mic do the work it is supposed to, and translates it beautifully.