Lavry AD11 Manual - page 19
AD11
Specifications
15
All three digital outputs are available at all times, so multiple recording or monitoring devices can be
connected to the AD11. Please note: there will be a difference in the (short) “delay” between when
computer software receives the USB input signal and when a non-computer device receives an AES
or SPDIF signal. In most cases, a non-computer device that accepts an AES or SPDIF signal will
appear to receive it almost instantaneously; while a computer will have a more significant delay
because of the buffering needed for the USB interface and RAM buffering required to stream the
digital audio into and out of the computer/software, as well as RAM buffering needed for any
processing by plug-ins. This is also true of computers receiving the digital audio signal via an AES or
SPIDF digital audio interface (PCI soundcard, FireWire, or USB).
This is due to the nature of computer audio, and is not unique to the AD11, which has a conversion
delay similar to most other contemporary AD converters.
The AD11’s conversion delay is related to
the Sample Frequency (SF), and is shorter for higher SF’s. The total delay will vary with buffer
settings and the type of interface used (USB, or for AES/SPDIF inputs; a soundcard or USB/Firewire).
It is strongly recommended that the user tests the delay when using multiple types of converters in
multi-channel systems by recording some form of transient signal and measuring the difference in
relative position in the recording software
. If some form of “delay compensation” is not available in the
recording software
and
the difference is musically significant, the user can manually offset the
position of the recorded track. “Musically significant” can be a matter of opinion; but generally
speaking a difference of 1-2 milliseconds between different instruments or vocals is not significant
because this is equal to an
“acoustic delay” caused by a difference in the distance between the mic
and source of 1-2 feet.
Short delays are much more critical for “correlated” sounds such as a stereo
recording of one instrument with two microphones. For this reason, it is recommended that the same
converter unit be used to record both channels of a stereo source.
The AD11 should be placed or mounted in a manner that allows airflow around the sides and top of
the unit. Although the AD11 does not generate a large amount of heat, operating it with insufficient
ventilation or in a high ambient temperature condition could cause the heat to build up internally,
which could lead to premature failure of the electronic components.
SPECIFICATIONS:
GAIN Control Precision- Gain 0-12dB:
Integral linearity (deviation from straight line)
– better than 0.1dB
Differential linearity (step size)
– better than 0.08dB
AD dynamic range > 110dB A-weighted 0-12dB gain
AD distortion THD+N Better than .001% input: 1kHz, -3dBFS 0dB gain
Microphone Gain range: 20-65 dB 1dB steps
MicPre+AD: Dynamic range referenced to: 0dBFS digital level un-weighed 20-20k
20dB >108dB
40dB >106dB
60dB >90dB
MicPre Distortion: THD+N >.001% Input +4dBu 20dB gain = 0dBFS
Maximum Input level to achieve “0dB Full Scale” digital level (Analog levels + 0.25 dB):
XLR Balanced input:
With gain set to 0 dB
+24dBu
With gain set to 12 dB +12dBu
With Gain set to 20 dB +4dBu (Only for low impedance balanced sources- typically microphones)