SOURCE CONNECTIONS
TUNER INPUT:
Refer topictorial
A
This
is
a high-level input with a rated sensitivity of 0.2 Volt. Although
labeled TUNER (AM or
FM),
this input may be used with any high
level source. The rated input impedance is
36K
Ohms with the volume
at maximum and increases to
53K
Ohms when the volume control
is
at
minimum. This condition exists only with the push-button source
selector inthe "TUNER" position, otherwise
it
is zero Ohms (Shorted).
NOTE: By design, THOEBE's high level inputcannot be overloaded by
any normal source.
AUXILIARY INPUTS:
Refer topictorial
A
The two stereo input pairs provided, labeled AUX 1 and AUX 2, are
identical in operation and sensitivity to the TUNER input described
above. They can be used with any auxiliary equipment havingadequate
outputs such as tape recorders, tuners, etc.
TAPE INPUTS:
Refer to pictorial
A
8
B
Two stereo pairs are provided, labeled TAPE 1 (Located on the rear
panel), and TAPE IN (Locatedon the front panel). These inputs, having
identical impedances and sensitivities as the TUNER input, are for
connection to tape recorder line outputs.
NOTE: TAPE 2 and Front Panel TAPE IN are connected in parallel
and are bothswitched by TAPE 2 switching.
PHONO INPUTS:
Refer to Pictorial
A
Two sets of phono inputs are provided; both are designed for use with
conventional magnetic phonographcartridges, see below.
MAGNETIC PHONO: All conventional magnetic cartridges (and
other types which require RlAA playback equalization but which do
5
not require input sensitivities below 1.6mV) may be used with this
input. The rated input impedance
is
47K
Ohms (100 pF shunt
capacitance) which is standard for magnetic phonograph cartridges.
Overload capability is
I
lOmV at
I
kHz which will accommodate
cartridgesconsideredtobe "High-output" types.
Well- shieldedcable is recommendedfor connecting tothe cartridge and
is usually supplied as part of the turntable or changer. Where longer
distances are desired for this connection,
it
is
not recommended the
phono cables exceed
5
feet, otherwise audible degradation of high
frequencies might be encountered. Special care must be taken than all
connections are tight and secure.
Ordinarily, an additional grounding wire
is
provided with the turntable
which should be connected to the grounding post located between the
phono inputs on the rear panel. Insome systems,
it
might be found that
this connection creates hum. Inthis case, noground connection should
be made. Be careful to keep all large transformers (such as found in
power amplifiers) away from the phono cartridge to prevent
magnetically-induced hum.
SPECIAL NOTES ON HUM REDUCTION
Unfortunately, by the very nature of the component, some components
are more prone to hum than others; no cable made is entirely immune
to radiated magnetic flux (hum). It follows then, that all cables inthe
system must be oriented for the lowest level of hurn.
The connecting cables from the turntable will pick up far more hum
than any other source. These cables must be oriented for maximum
hum cancellation. All wires carrying
AC
power should be located as far
away from the turntable and preamp input as is physically possible.
Under no circumstances should you ground the turntableor grounding
post to a water pipe or other such ground. Only through the power
amplifier should your system be grounded toearth.
Humcan also be introducedby a poor cable connector contact with the
outer grounding shell of the plug. Make sure that the outer shells on
RCA phono plugs are squeezed together enough to provide an
absoulutely solid ground connection. Try rotating the plugs to obtain
the best possibleground.
