Lavry AD122-96 Mark III Operation Manual - page 5
AD122-96 MKIII
Operations Manual
4
PART I: Introduction
The
Model AD122-96 MKIII Mastering Quality Analog to Digital Converter
receives analog input
signals at the left and right analog input channels. The converter can receive balanced or unbalanced
analog input signals. Individual left and right analog gain adjustment can be achieved via the front panel
adjustment pots. Fine tuning of reference levels can be achieved by setting the front panel bar graph
display (LED's) to “Fine” mode (reference meter bridge). The digital output is available at the AES/EBU
output.
Front panel selection enables setting word length between 16 and 24 bits (NI is a 20 bit setting as per
AES/EBU specifications). The recommended normal setting for word length is 22-24 bits (the audio
content utilizes 22 bits). Lower bit settings are aimed at redithering using the available Acoustic Bit
Correction™ feature. Redithering to smaller words retains much of the acoustic information in the full
word width output.
The converter can operate with internal or external clock synchronization. Available internal crystal
frequencies are 44.1 kHz, 48 kHz, 88.2 kHz, or 96 kHz. For external synchronization, a signal is applied
to either the SYNC/WC input or the Word Clock input. The external synchronization parameters are
programmed into the converter according to desired frequency lock range and input type. The input types
are digital audio (AES/EBU) or word clock signals. The desired frequency lock range settings are
44.1 kHz narrow lock range, 48 kHz narrow lock range, 40-50 kHz wide lock range, 88.2 kHz narrow lock
range, 96 kHz narrow lock range, 88/44 kHz, or 96/48 kHz.
Vernier Transfer Function Correction™:
The exceptional performance of Lavry Engineering’s
AD122-96 MKIII
is due to design innovations in
both analog and digital sections. The high power consumption of the A/D modules, using high voltage
rails and high current, enables the use of discrete large geometry components. This provides advantages
from improved circuit architecture-- including class A amplifiers for fast settling and lower distortions,
and the use of low value resistors for lower noise.
The performance of the low-noise high-linearity converter is optimized by a set of proprietary algorithms
utilizing a "digital vernier" technique which provides superior resolution and correction for changes in
circuit parameters, including component drift due to temperature and aging.
Additional features:
Test Tones: a fully programmable digital test tone generator for calibration.
D.C. Removal: enables conversion of signals down to 0 Hz. D.C. removal is achieved by subtracting the
offset from the signal.
Polarity Inversion and Soft Saturation: for emulating analog tape saturation.
User-Defined Power-Up Default Setting
Stereophonic Bar Graph Display: features wide dynamic range; the bar graph can be extended by 30, 60
or 90dB for viewing the noise floor. The bar graph may also be altered for use as a reference meter
bridge.
Clip Indication: when digital full scale indication is enabled, the full scale “MAX” light holds until reset
by the user.
Format Control: pro or consumer data format. When in consumer mode the user can choose category,
C and L bit settings.