46 Australian Hi-Fi http://www.avhub.com.au
LAB REPORT
Questyle CAS192 DAC Test Restults (AES-17 using 48kHz/24-bit)
Digital Section Result Units/Comment
Out of Band Spurious Components 106.906dB
Suppression of Imaging Components 106.857dB (Worst Case)
Level Dependent Logarithmic Gain 1.964dB
Intermodulation Distortion (1) 99.851dB 18kHz/20kHz 1:1 Ratio
Intermodulation Distortion (2) 100.304dB 41Hz/7993Hz 4:1 Ratio
Low Level Noise Modulation 5.268dB Worst Case
Idle Channel Noise 111.06dB CCIR-RMS weighting
Signal-to-Noise Ratio 111.744dB CCIR-RMS weighting
Power Line Products 113.079dB 50Hz
Non-Linear Interchannel Crosstalk (a) 109.329dB 3kHz (2nd-order ref 17kHz/20kHz)
Non-Linear Interchannel Crosstalk (b) 121.626dB 6kHz (3rd-order ref 17kHz/20kHz)
Non-Linear Interchannel Crosstalk (c) 117.571dB 10.040kHz (2nd re 40Hz/10kHz)
Non-Linear Interchannel Crosstalk (d) 105.022dB 10.080kHz (3rd re 40Hz/10kHz)
Absolute Phase Inverting Normal/InvertedQuestyle CAS192 Golden - Test Results (44.1kHz/16-bit)
Analogue Section Result Units/Comment
Output Voltage 4.9337 / 4.9283 volts (Left Ch/ Right Ch)
Frequency Response See graphs dB (20Hz – 20kHz)
Channel Separation dB at 16Hz / 1kHz / 20kHz
THD+N 142 / 132 / 110 @ 1kHz @ 0dBFS
ChannelBalance 0.009dB @1kHz@0dBFS
ChannelPhase 0.01/0.02/0.36 degreesat16Hz/1kHz/20kHz
GroupDelay 180/4.71 degrees(1–20kHz/20–1kHz)
Signal-to-Noise Ratio (No Pre-emph) 105 / 109 dB (unweighted/weighted)
De-Emphasis Error Not Enabled at 1kHz / 4kHz / 16kHz
LinearityError@–60.00dB/–70.00dB 0.00/0.06 dB(TestSignalNotDithered)
LinearityError@–80.59dB/–85.24dB 0.01/0.02 dB(TestSignalNotDithered)
LinearityError@–89.46dB/–91.24dB 0.03/0.01 dB(TestSignalNotDithered)
LinearityError@–80.70dB/–90.31dB 0.10/0.06 dB(TestSignalDithered)
Power Consumption 3.66 / 5.11 watts (Standby / On)
Mains Voltage During Testing 238 - 243 (Minimum – Maximum)Questyle Reference System Golden Edition
Continued on page p82Measured with extremely low-level test
signals, down around –90dB, the Questyle
CAS192D delivered excellent performance,
no matter whether the test signals were dith-
ered (Graph 10) or undithered (Graph 11).
The undithered signal results in the CAS192D
delivering some odd-order harmonic dis-
tortion, but all components are more than
109dB down (0.00035%). Dithering the test
signal results in a rise in the noise floor, but
as you can see, that noise floor is still down
around –140dB, and dithering also removes
almost all the distortion components, with
the two that are left sitting down at –122dB
(0.00007%) where they’d be completely
inaudible. The THD+N results with AES-17
signals were similar, but slightly better than
the results for CD-Standard signals as you can
see in Graph 12.The THD vs. Level results for AES-17 are
shown in Graph 14.
Intermodulation distortion (CCIR-IMD)
using 44.1kHz/16-bit test signals was
extremely low, as you can see in Graph 13,
with all high-frequency sidebands more than
110dB (0.00031%) down, and the unwanted
regenerated 1kHz signal down at –118dB
(0.00012%). The very few high-frequency
sampling-related products that are visible on
the graph (far right) are nearly 120dB down.
Using AES-17 IMD signals the overall results
were –99.851dB for 18kHz/20kHz 1:1 ratio
IMD and –100.304dB for 41Hz/7993Hz 4:1
ratio signals, which are also excellent results.
Channel separation was excellent for both
digital standards tested, with the results tabu-
lated for 44.1kHz/16-bit and shown in Graph
15 for 48kHz/24-bit signals.
The results achieved using the CD stand-
ard are absolutely outstanding, with Newport
Test Labs measuring 142dB at 16Hz, 132dB at
1kHz and 110dB at 20kHz. Channel balance
was equally outstanding, at 0.009dB, while
interchannel phase was 0.01 degrees at 16Hz,
0.02 degrees at 1kHz and 0.036 degrees at
20kHz.The results achieved
using the CD standard
are absolutely
outstanding