Specifications

Prism Media Products Limited AD-2 Dual-rate A/D converter
Operation Manual
Issue 0.2 © Prism Media Products Limited
11 August 1998 Page 41 of 58
Level-dependent logarithmic gain linearity: << 3dB at -144dBFS
Note: This is a measurement of the output level of a 996.115Hz tone with respect to the input level. The output
level at 997Hz is measured using 32 averages of an 8192 point FFT with a rectangular window. This method
has much higher resolution than the test in AES17, which specifies a third-octave band-pass filter to eliminate
noise. Even so, the signal level measurements are still dominated by the noise floor at -144dB FS.
7.1.4. Phase-related
Group delay: Nominally 102/fs (1.06ms at fs=96kHz)
Phase linearity error (5Hz - 20kHz): <1E
Inter-channel phase deviation (5Hz - 20kHz): < 0.5E
Absolute phase: Correct
Note: Negative analogue inputs produce a negative digital output. Thus if pin 2 of the input connector is
negative with respect to pin 3 the most significant bit of the (2s complement) digital output is set. This is in
accordance with the standards IEC268-12(1969) and AES14.
7.1.5. Jitter
Sampling jitter rejection:
Jitter attenuation slope: 80dB per decade
Corner frequency: approx 80Hz
Attenuation above 500Hz: > 60dB
Intrinsic conversion jitter: <18ps RMS
7.2. Analogue Inputs
The analogue inputs are connected via a pair of 3-pin female XLR connectors with
positive and negative signal polarities on pins 2 and 3 respectively. Pin 1 is coupled to
the chassis using a capacitor and resistor to limit screen currents and provide EMC
coupling.
Differential input impedance: 20 kS (pin 2 to pin 3)
Common mode input impedance: >200 kS (pin 1 to 2 or 3)
Common-mode range: 70 V