Earthworks 1021 User Manual

EARTHWORKS FIFTEEN-YEAR

Limited Warranty

Earthworks, Inc. warrants this product to be free of defects in material and work­manship for a period of fifteen years from the date of original retail purchase.
This warranty is enforceable only by the original retail purchaser. To be protected
by this warranty, the purchaser must complete the warranty registration either by
mail the enclosed warranty card or on the Earthworks website within 14 days of
the date of purchase. During the warranty period Earthworks shall, at its sole and
absolute discretion, repair or replace, free of charge, any product that proves to be
defective on inspection by Earthworks. To obtain warranty service, the purchaser
must first call or contact Earthworks at the contact information listed below to
obtain a Return Merchandise Authorization number (RMA#) and instructions
of where to return the unit for service. All inquiries must be accompanied by
a description of the problem. All authorized returns must be sent to the Earth­works repair facility postage prepaid, insured and properly packaged, preferably
in the original packing material. Earthworks reserves the right to update any
unit returned for repair. Earthworks reserves the right to change or improve the
design of the product at any time without prior notice. This warranty does not
cover claims for damage due to abuse, neglect, alteration or attempted repair
by unauthorized personnel, and is limited to failures arising during normal use
that are due to defects in material or workmanship in the product. Any implied
warranties, including implied warranties of merchantability and fitness for a par­ticular purpose, are limited in duration to the length of this limited warranty.
Some states do not allow limitations on how long an implied warranty lasts, so
the above limitation may not apply to you. In no event will Earthworks be liable
for incidental, consequential or other damages resulting from the breach of any
express or implied warranty, including, among other things, damage to property,
damage based on inconvenience or on loss of use of the product, and, to the
extent permitted by law, damages for personal injury. Some states do not allow
the exclusion of limitation of incidental or consequential damages, so the above
limitation or exclusion may not apply to you. This warranty gives you specific
legal rights, and you may also have other rights, which vary from state to state.
This warranty only applies to products sold and used in the U.S.A. For warranty
information in other countries please refer to your local distributor.

Precision Microphone Preampliers

Featuring David Blackmer’s

Zero Distortion Technology

™

Owner’s Manual

1021 Single Channel

For an RMA# or questions about service please email:
[e-mail] or phone [phone], ext. 19

Earthworks, Inc.

37 Wilton Rd.

Milford, NH 03055 USA

Phone: [phone]

Fax: [phone]
earthworksaudio.com

Made in U.S.A.

1022 Two Channel

1024 Four Channel

Description

Earthworks Zero Distortion TechnologyTM (ZDT) precision micro­phone preamplifier is a discrete-component Class A bipolar input circuitry de­vice. The primary signal path from the balanced XLR input to a balanced and
symmetrical XLR output is completely differential (the signal is never converted
to single-ended). The are no transformers or electrolytic capacitors in the signal
path. All connectors and switches are gold-plated.
The ZDT preamplifiers have extremely flat wideband frequency re­sponse from 1Hz to 200kHz, slew rate of 22V/μs, and the lowest self-noise
available from any preamplifier on the market. The nonlinear distortion is kept
well below one part per million even at the highest signal levels (below clipping).
Each channel has separate phantom power switch, polarity reversal, and mute
switch that turns off the output while keeping the microphone powered and the
gain unchanged. A separate 1⁄4” output has additional vernier gain reduction of
up to 20dB after the stepped gain.
The ZDT preamplifiers are available in single (Model 1021), two­(Model 1022), or four-channel (Model 1024) versions. The multi-channel pre­amplifiers have separate signal boards divided by electromagnetic shields to mini­mize crosstalk.

Specications

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

Settling Time: 1.4μs

Distortion: XLR out: less then 1ppm (0.0001%); 1⁄4” out: 0.001%

Input Noise SD Enoise: 1.6nV/Hz1⁄2 @ 20dB gain; 0.6nV/Hz1⁄2 @ 60dB gain

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

Slew Rate: 22V/μs

Output DC Offset: ±1mV typical, servo balanced

Power Requirements: 120V AC (100V and 220-240V versions available)

Inputs: XLR3-F balanced transformerless

Input Impedance: 10kohm phantom ON, 100kohm phantom OFF

Outputs: XLR3-M balanced transformerless (stepped)

1⁄4” TRS Jack balanced transformerless (variable)*

Output Impedance: 5 ohm nominal

Max. Output Level: +33dBu (37V peak-to-peak)

Dimensions H x W x D: 1 rack space 1.75” x 19” x 10.375” (1021 is 1⁄2 rack)

Weight: 1024, 1022: 6lb (ship.: 10lb); 2.7kg (ship.: 4.5kg);

1021: 4lb (ship.: 7lb); 1.8kg (ship.: 3kg)

Specications subject to change without notice.

*note: on some units the 1⁄4” TRS outputs may be incorrectly labeled as “unbalanced”

Version 4, June 7, 2011

Block Diagram of the Signal Path

Front Panel (one channel)

48V phantom switch Clip indicator
(yellow LED) (red LED)

polarity
reversal
switch

output
standby

stepped gain switch
5 to 60dB to XLR
output

variable gain
0 to -20dB from the
step (1/4” output)

power indicator
(green LED)

Rear Panel (one channel + power)

IEC power
connector fuse
compartment

Important: the XLR stepped output is fully differential, that is, it has equal and opposite
signal present on pins 2 and 3. NO extra gain stage is used, and the preamp relies upon
the signals on pins 2 and 3 to be equal and opposite for distortion correction. Never

short pin 2 or pin 3 of the male XLR output connector to ground (pin 1)!

AC voltage and
serial number

variable gain
out (balanced)

stepped gain
out (balanced
symmetrical)

mic input