Atec Audio-Precision-ATS-1A_ATS-1DD - Manual (Page 4)

Turn on ATS-1: Audio Testing to Meet Your Challenges
Comprehensive Analog and
Digital Functions
Digital Performance:
ATS-1 Dual Domain uses a true DSP-imple-
mented analyzer for digital measurements,
which results in –130 dB residual THD+N,
0.01 dB flatness, and –140 dBFS residual
noise. Other mixed-signal test sets in the
same price range have no digital analyzer,
but use a D/A converter and an analog ana-
lyzer. These architectures “bottom out” at
–70 dB to –84 dB residual THD+N (12–14
bit effective performance), and 0.1 dB flat-
ness. With today’s best A/D converters
measuring –108 to
–112 dB THD+N,
their real perfor-
mance is invisible
to these mixed sig-
nal analyzers
…buried under the
analyzer’s noise and
distortion floor.
Separate & Independent Analog & Digital
Generators:
Often necessary for dual domain testing.
You may, for example, drive the inputs of an
A/D converter with the low-distortion ana-
log sine while simultaneously driving the
converter’s digital reference (house sync)
input with the digital generator. Then, add
jitter or vary the sample rate to see the ef-
fect on THD+N, IMD, or noise. Competitive
units can drive only one domain at a time
or use their analog generator to create the
digital jitter, and thus can’t make this mea-
surement at all.
Separate Digital Inputs & Outputs:
Three I/O formats: XLR, BNC, and optical
(Toslink®). All are completely separate from
the analog audio XLR connectors, permit-
ting both digital and analog generators to
operate simultaneously. No cable changes
required to go from A/D to D/A to D/D to
A/A testing of a digital tape machine, for
example.
Digital & Analog Monitors:
Listen to all measurements in the digital
and analog do-
mains over the
internal loud-
speaker or a
pair of head-
phones. In the analog domain, monitor
signals or distortion. In the digital domain,
the incoming signal, distortion, or jitter
can all be monitored.
Jitter Meter:
ATS-1 Dual Domain includes jitter measure-
ment in nanoseconds or in Unit Intervals.
Two filter selections are provided for the
jitter meter: a 700 Hz high-pass filter used
for residual jitter measurements according
to AES standards, and a 50 Hz high-pass fil-
ter for jitter response measurements.
Other Interface Signal Measurements:
ATS-1 Dual Domain measures key digital I/O
interface parameters in addition to jitter,
including sample rate, AES signal voltage,
frame delay through the device under test,
and delay of the input signal relative to a
house sync reference (frame or block).
Flexible Interface Impairment Simulation:
Flexible digital interface testing is vital for
troubleshooting and verifying performance
of digital audio at the systems level. ATS-1
Dual Domain allows simulation of real world
transmission and interface problems.
Vary the digital output signal to test the ac-
ceptance range of your digital devices. Set
sample rate anywhere from 28.8 kHz to
99.9999 kHz, not just at the three standard
frequencies. Inject jitter amplitude from
0 UI to 2.5 UI (415 ns at 48 kHz) in
0.01 UI (1.6 ns) steps, or 0 UI to 25.5 UI
(4150 ns) in 0.1 UI (16 ns) steps.
A competitive instrument lacking a
DSP analyzer produces false THD+N
readings (red trace) from a popu-
lar A/D converter; but both the
ATS-1 Dual Domain and the Audio
Precision 2700 Series graph the
true performance of the converter
(from 5 dB to 28 dB lower), as
shown by the blue trace.