Sony TC-K511S - Optimizing Recording with Calibration

CALIBRATION—— BIAS —— REC LEVEL
GY G
Adjusts the bias
current within a
range of about +20%
Adjusts the recording
level within a range of
about +3 dB
Bias AS Bias Bias reduced (-)
reduced NN increased
a
(high- (high- =E
frequency Ñ frequency a g
response
*
response
6s
Bias
increased
(+)
boosted) suppressed)
Frequency in Hz
18
Making an Optimum
Recording
Bias and Recording Level
Calibration
There are many different types of cassettes
on the market, each with varying magnetic
properties. Although your unit is equipped
with the ATS (Automatic Tape Selection)
system which sets the appropriate
equalization characteristics and bias current
for each tape type, an additional calibration
adjustment can often produce even better
results. Use the bias current and recording
level calibration function to obtain the
optimum recording conditions for your tape.
Fig. E shows the BIAS control and REC
(recording) LEVEL control for calibration.
Bias calibration
Choosing the optimum bias current for a
tape ensures minimum distortion and flat
frequency response. Lowering the bias
current boosts high-frequency response,
but also results in higher distortion. Raising
the bias, on the other hand, reduces
distortion, but also dampens high-frequency
response. Optimum bias is thus obtained
when the bias current and high-frequency
response are well balanced.
Fig. [EJ shows the BIAS control and a high-
frequency response balance chart.
e If the bias current is higher or lower than
the optimum setting for a certain tape, the
frequency response changes as shown in
the Chart in Fig. [J . Changing the bias
can thus be used to tailor the response to
your liking, for example by slightly
emphasizing the upper or lower end.
The frequency response of metal tapes is
much less affected by changes in the bias
current than other tape types, and in some
cases is uneffected. With some tapes, the
adjustment range of this deck (a range of
about +20%) may therefore not be
sufficient to cover every possible
requirement.
Recording level calibration
Even when the recording level is adjusted
correctly, using a tape with low sensitivity
will result in a low playback level. The REC
LEVEL calibration control allows you to
compensate for sensitivity differences
among tapes to equalize both recording and
playback levels. This is especially important
when using the Dolby NR system, since it is
most effective when recording and playback
levels are the same.