Kolpak DA-98 Manual De Usuario
Section 8 – Advanced operations
8-10 – 1.00 – 06/97
input bits, as in the case of the DA-98) to a lower
number (for instance 16, the DA-98’s tape word
length) to improve quantization.
number (for instance 16, the DA-98’s tape word
length) to improve quantization.
Paradoxically, this technique of adding noise
removes quantization noise and distortion at low
signal levels and improves the overall distortion
figures.
removes quantization noise and distortion at low
signal levels and improves the overall distortion
figures.
1
Though quantization noise is reduced, there is a
loss of a few dB in the signal-to-noise ratio. For
this reason, the DA-98 does not implement dither
as a standard, but allows you to choose between
no dither, rectangular or triangular (the shapes
refer to the distribution of values in the digital
noise). Rectangular gives about 3dB better signal-
to-noise ratio than triangular, but there is noise
modulation, which may be audible when record-
ing and playing back low-level program sources.
loss of a few dB in the signal-to-noise ratio. For
this reason, the DA-98 does not implement dither
as a standard, but allows you to choose between
no dither, rectangular or triangular (the shapes
refer to the distribution of values in the digital
noise). Rectangular gives about 3dB better signal-
to-noise ratio than triangular, but there is noise
modulation, which may be audible when record-
ing and playing back low-level program sources.
8.13.1 Selecting dither settings
1) Select menu group 1, move the cursor to
Dither
and press
ENTER
.
2) Use the
UP
and
DOWN
keys to select the dither
function you want, and press
ENTER
to confirm
the setting.
1
A full discussion of dither and other digital audio tech-
niques is outside the scope of this manual. However, a
good starting point for learning about this, and other
aspects of digital audio, is John Watkinson’s The Art of
Digital Audio, pub Focal Press.
good starting point for learning about this, and other
aspects of digital audio, is John Watkinson’s The Art of
Digital Audio, pub Focal Press.
8.14 Setting the power-on
message
You can set a power-on message of up to 20 char-
acters (letters, numbers and some punctuation)
which will be displayed when the DA-98 is turned
on.
acters (letters, numbers and some punctuation)
which will be displayed when the DA-98 is turned
on.
The default message is
TASCAM
.To set a message
other than this:
1) Select menu group 2, move the cursor to
PwrOn Msg
and press
ENTER
:
2) To clear the current message, use the
LEFT
and
RIGHT
keys to move the cursor to
CLEAR
and
press
the ENTER key
.
3) Use the
LEFT
and
RIGHT
keys to move the
cursor to the left field, and press the
UP
and
DOWN
keys to select a character.
Characters available are:
A
through
Z
,
-
,
.
,
[space] and
1
through
9
(you can use the letter
“
O
” for the “
0
” (zero) character).
4) Press
ENTER
to confirm the character and add
it to the end of the power-on message.
5) Press
ESCAPE
when all characters have been
entered.
NOTES
•
We suggest using the confidence mode of off-tape mon-
itoring when recording using dither in order to be able to
check the effect instantly (see 7.2, “Confidence mode”).
itoring when recording using dither in order to be able to
check the effect instantly (see 7.2, “Confidence mode”).
•
Dither can be turned on and off while recording is tak-
ing place. However, there will probably be an audible
change in the sound quality. We suggest making a test
recording before a session using confidence mode. In
this way you will be able to make an instant assessment
of the effects of the different dither settings on your pro-
gram material.
ing place. However, there will probably be an audible
change in the sound quality. We suggest making a test
recording before a session using confidence mode. In
this way you will be able to make an instant assessment
of the effects of the different dither settings on your pro-
gram material.
D i t h e r
R e c t a n g u l a r
P o w e r - o n
M e s s a g e
R O C K J O E
S T U D I O S
S
C L E A R
I N I T
NOTE
To reset the message to
TASCAM
, move the cursor
to
INIT
and press the
ENTER
key. The
current
message will be erased and replaced.