8
INPUT SIGNAL shows the
selectedinputsource.Thissignal
isalsoindicatedontherearpanel
by lighting the selected signal
GreenLED.
The WORD CLOCK must be set
to the appropriate source
otherwise clicks, pops or even
loud white noise may be heard.
Whensetting up fora new signal
sourcefirstly select themode for
RECORD or PLAY (each mode
has its own set of input, Limiter,
Word Res etc. settings)
ALWAYS reduce to monitor
volumebeforechangingtheinput
signal or word clock source to
prevent damage to ears or
speakers.
InputSignal
BASICEFFECTS
Thelimiter will onlyhaveanyeffectwhen‘DIGITAL
GAIN’ is set greater than 0dB.
Thereare several attack/decaysettings:
use‘SLOW’for least intrusive signal levelingwith
up to 18dB of gain,
‘MED’to increase to perceivedvolumewith up to
+12dBof gain,
‘FAST’ for transientcapture.
Note: if more than +9dB of ‘DIGITAL GAIN’ is
applied then it is possible hear the limiter
pumping,
use‘HOLD’tonormalise the signal to exactly 0dB.
Select ‘HOLD’, play the track using +18dB of
‘DIGITAL GAIN’then rewind and thetrackwill be
readytoplay with its max peaks unlimitedat 0dB.
Re-selectthe‘HOLD’LEDtore-settheholdlevel.
The‘LIMIT’meter LED will remain lit when‘HOLD’
isselected and theinputsignal has been limited,
untilthe ‘LIMITER’ button is pressed.The‘LIMIT’
LED will also remain lit for up to 10 seconds as
the limiter releases when ‘SLOW’ and the input
signalhas been severlylimited.
Limiter
WORDRESOLUTIONdefinesthe
numberof bits per audiosample,
ie: Standard audio CD is 16bits.
This must match the recording
medium otherwise ‘Truncation’
distortion will occur. Truncation
distortioncannot beremovedafter
recording by adding dither to a
truncatedsignal.
Whenword resolution is reduced
to less bits than the original then
dithermustbeaddedto mask the
distortionthatiscausedwhenthe
bits are lost.
If the DC2496 A/D is 24bit
resolution,when reducing thisto
16bits for a DAT recording
normallybestresults are obtained
withHF dither.
WordResolution
H.Fdither generally removes the
low level distortion on low signal
levels with the least noticable
noise.
M.F dither produces the lower
distortion with a slight increase
innoise over H.F dither
DUALditherproduces the lowest
distortion but still has much less
perceivednoisethanWhitenoise
dither.
Whitenoiseisthestandarddither
addedtoprevent distortion on low
level signals when the WORD
RESOLUTION of a signal is
reduced, ie. 24bit recording
reduced to 16bits. It offers poor
performancein termsofperceived
noise.
Dither
Chapter 2DC2496 BASIC EFFECTS
CHAPTER 2
