Teac V-2030S - Dolby Hx Pro; Troubleshooting

Maintenance (Fig. 7)
The heads and tape path should be cleaned
and demagnetized periodically.
Cleaning Tape Path
eApply head cleaning fluid* to special
cotton swabs or a soft cloth, and lightly
rub the heads, capstans and all metal parts
in the tape path,
Also clean the pinch rollers using rubber
cleaning fluid*.
*Both are available in TEAC HC-2 and
RG-2 in the U.S.A. or TEAC 12-261
Tape Recorder Cleaning Kit in other
areas,
Demagnetizing Heads
Be sure that the power is off, then demag-
netize the heads using a TEAC E-3 demag-
netizer or equivalent, For details of its
use, read the instructions,
Troubleshooting
Basic troubleshooting of a cassette tape
deck is similar to troubleshooting any other
electrical or electronic equipment. Always
check the most obvious possible causes first.
To give you a few ideas of what to look for,
check the following:
@ No power: Is the power cord connected?
© Tape begins running when power is turned
on: Is the TIMER function on?
No audio output: Are all connections
properly made?
Degraded sound quality: Are the heads
dirty or magnetized? Are you using a
good quality tape? Is the proper NR
System select switch on?
Unable to select record mode: Are the
record protection tabs on the tape in
place?
DOLBY HX PRO
a
Dolby HX Pro is an “active bias” technique
‘that can improve the quality of audio tape
recordings. High-level high frequencies can
be recorded more accurately, without
sacrificing signal-to-noise ratio, while such
side effects of tape saturation as distortion
are reduced.
What Is Bias?
Bias is a very high-frequency signal generat-
ed within a tape deck and recorded on the
tape simultaneously with the program
material. This inaudible signal allows a low
noise, low distortion recording and flat
frequency response, Different magnetic tape
formulations require different amounts
of bias for optimum performance, If the
bias level is too high, high-frequency
Maximum Output Level (MOL) decreases.
The Problem of Self-Bias
Unfortunately, bias level is often influenced
by the signal being recorded. The high fre-
quencies contained in soma music act as
added to the existing bias, resulting in a loss
of high-frequency response. As the high-
frequency content of the signal increases,
the ability of the recorder to record high
frequencies (MOL) decreases. This pheno-
menon is called self-biasing.
The Dolby HX Pro Solution
The Dolby HX Pro monitors the high-
frequency content of the program material
and adjusts the recorder bias oscillator to
maintain a constant total bias level. The
result is improved high-frequency response
and lower distortion. Depending on tha type
of tape, the improvement in headroom can
be 6 dB or more.
The Benefits
With Dolby HX Pro, it is easier to make
more accurate recordings of the kind of
music which contains high-level high fre-
quencies, The improvement is similar to
that of high-performance tape over conven-
tional tape, so regardless of the type of
tape used, the results will sound better.
Most important of all, Dolby HX Pro
requires no decoding process. Once the
tape is recorded with it, the improvements
will be realized when playing the tape back
‘on any machine,
~40 |
20Hz 50 100 200
1k 2 5 10 20k
Example of improved frequency response using Dolby HX Pro function