User Guide

dCS Elgar Plus User Manual Manual for Software Issue 4.3x
dCS Ltd September 2004
Manual filename: Elgar Manual v4.3x.doc Page 20 email: [e-mail]
English version web-site: www.dcsltd.co.uk
Menu Sequence
Use the flow chart (Figure 7) or the Control Summary sheet to guide you
through the Menu more quickly.
The following explanation deals with the Function Menu pages in the sequence
they occur in the Menu
3
. The use of each page is shown on an individual basis,
with the last operation being closing the Menu. After you have become more
familiar with the Menu, you will find it more convenient to perform all the
Function Menu operations in one go before finally closing the Menu.
Filter
FilterFilter
Filter – Anti-Imaging Filter Setting
Elgar Plus offers a choice of 4 interpolation filters for 5 sample rates (32kS/s,
44.1kS/s, 48kS/s, 88.2kS/s and 96kS/s) and 6 for two (192kS/s and 176.4kS/s).
The filters offer differing responses. In each case, Filters 1-4 are symmetrical
filters (with time response before a transition the mirror image of time response
after). Filter 1 offers the sharpest cut-off, least Nyquist imaging but longest
energy smear. Filter 4 gives the gentlest roll-off (usually with significant Nyquist
imaging) but the shortest transient response with least energy smear. Filter 5 is
a Gaussian filter, and Filter 6 is an asymmetrical filter – there is almost no time
response prior to the initial step.
For units fitted with a 1394 interface, DSD mode also offers four filters, but
these are intended to progressively reduce the out-of-band noise level. Filter 1
generally gives the widest bandwidth, but results are system dependent – if
your system gives undesirable effects with Filter 1, try (in this order) Filter 2
then Filter 3 then Filter 4. These reduce the out-of-band energy at the
expense of reduced bandwidth. Filter 4 is really intended for metering
applications, not for listening.
Elgar Plus remembers the last filter selection made for every sample rate. So, if
you choose Filter 4 for 96kS/s and Filter 6 for 192kS/s, these separate
settings will be stored and loaded when the incoming sample rate changes
(usually when selecting a different input or changing the Upsampler settings).
Selecting a Filter x
We encourage you to experiment with the filters, to find the one that sounds
best for your particular application. Do not assume that one filter is best for all
applications!
4
do this: Assume for the purpose of this illustration that the sample rate is 96kS/s and
Filter is currently set to Filter 1. Open the Function Menu and step through
until the display shows Filter 1.
3
A minor software update may change the order of the menu items or add an option. If this happens, the
Control Summary sheet may be updated before the manual.
4
The reports we receive from users suggest that Filter 2 is well suited to some classical music, and that Filters
3 and sometimes 4 suit rock. Filters 5 and 6 are too new to have reports on, although the user may wish to
refer to “Effects in High Sample Rate Audio Material”, by M.J.Story, R.Kelly, D.A.McLeod, M.N.Harris,
presented at the 20
th
Tonmeister Tagung at Karlsruhe in November 1998. This paper is available from the
dCS web-site.