JOPLIN M
K
II
384
k
H
z
/32bit ANALOG-TO-DIGITAL CONVERTER
REVISION P
R
A – FEBRUARY 2015
Copyright © 2015, M2Tech Srl
46
M2Tech
www.m2tech.biz
8.3.2. Input choice
The
JOPLIN MKII
has two inputs: one analog (called “line”) and one coaxial digital
(called “coax”). The use of the former is straightforward, the latter has been included
to allow users to connect a digital source to a computer which is not provided with a
digital input, making a bridge between the S/PDIF and the USB. Please note that the
input sampling frequency on the coax input (set by the digital source) is generally not
the same as the output sampling frequency (set by either the USB driver or the user
via the configuration menu). An asynchronous sample rate converter performs the
sampling rate conversion between input and output. When such an operation is not
desired, user needs to set the output sampling frequency to the same value as the
incoming stream sampling frequency.
8.3.2. Input impedance
The
JOPLIN MKII
allows the user to set the analog input impedance to 9 different
values. This feature is mandatory when a phono pickup is connected to the input.
3 values suitable for MM pick-ups are available (47kΩ, 47kΩ parallel with 100pF and
47kΩ parallel with 220pF), 1 value suitable for certain high-output MC pick-ups, to
which the standard 47kΩ MM load may be too high (16kΩ) and 5 values suitable for
MC pick-ups (1kΩ, 500Ω, 200Ω, 50Ω, 10Ω).
8.3.3. Sampling frequency
The
JOPLIN MKII
can operate at the following sampling frequencies: 44.1kHz, 48kHz,
88.2kHz, 96kHz, 176.4kHz, 192kHz, 352.8kHz and 384kHz. The higher the sampling
