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TONE SWITCH
Regardless of the twin tone control settings, a com-
pletely flat response
can be obtained at any time
by setting the TONE
switch to OFF. The delicate
effects
of the tone
controls
and
their
optimum
adjustment according to different program sources
can then be evaluated.
LOAD RESISTANCE AND LOAD
CAPACITANCE
Typical
moving
magnet
(MM)
cartridges
have
resonance
peaks at high frequencies,
as shown
in
Fig. 12. However, the height of the peaks can be
varied by changing the load resistance (ohms). The
peaks
increase
as the resistance
is increased.
In
addition,
the resonance
frequency
(center of the
peak
frequency)
can
be varied
by changing
the
load capacitance
(pF), as shown in Fig. 18. If the
capacitance
is increased,
then
the resonance
fre-
quency is lowered and the peaks are increased. To
provide the best characteristics
of your cartridge,
set the "pF"' and '"'ohms'' switches, following the
instructions
outlined belows.
By combining
these
two knobs, you will be able to obtain a variety of
different high-frequency responses.
When the phono cartridge load resistance and
capacitance are specified
e Set the specified load resistance with the "'ohms''
knob.
Load capacitance
Load resistance
knob
knob
SOk
25k
400
10k
500
100
pF
ohms
CARTRIDGE
LOAD
(MM)
CARTRIDGE
LOAD
(MM) switches
Fig. 11
Examples of frequency
response variations due to
CARTRIDGE
LOAD ohms switch settings.
Impedance: high
Impedance: low
~—>Responce
—> Frequency
Fig. 12
12
e Subtract the turntable capacitance (stray capac-
itance
(stray
capacitance
of the output
cord,
tonearm,
etc.)
from
the
cartridge's
specified
capacitance and select this value with the "pF"
knob.
NOTES:
e
Refer to the operating instructions of the cartridge for
the specified load resistance and capacitance values.
e
Since the turntable capacitance varies with the output
cord,
wiring and
other factors, a precise value cannot
be definitely determined. In general, however, it can be
considered
to be in the range
of 100pF
to 200pF.
Adjust the load capacitance while listening to a record.
Table
1 — Makes of cartridges and recommended loads
type
PC-550E/TI (MM)
170
Pioneer
ADC
XLM
MKII
(IM)
275
AKG
P8E (MI)
400
Empire
2000Z (MI)
47k
300
Ortofon
VMS20E
(M1)
47k
400
Shure
V15 TYPE Il (MM)
47k
400—500
Stanton
680 EE (M1)
275
NOTE:
The capacitance of Pioneer's turntables ranges from 75pF
to 150pF. Subtract the capacitance from the load capac-
itance shown
in the table, and then set the switch
to the
value which is closest to the resulting figure.
For example, say you are using the PC-550E/II by Pioneer.
Subtract
100pF from
170pF
which gives 7OpF. Set the
CARTRIDGE
LOAD
switch to the closest figure, which is
"100'(pF).
When not specified
The
example
in Fig. 13
shows
typical high-end
frequency
curves.
In a case like this, adjust both
knobs for the desired response while listening to a
record. With ordinary MM cartridges, the values are
50 kilohms and 100pF — 200pF.
Examples
of frequency response variations due to pF
switch settings.
Capacitance: low
Capacitance: high
~> Response
—> Frequency
Fig. 13
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