Signal Connections - Eico HF-81 User Manual

b) INTERNAL POWER AMPLIFIERS COMBINED (TIED
TOGETHER AT THE INPUTS AND
PARALLELED AT THE
OUTPUTS) TO DRIVE ONE SPEAKER OF A STEREO PAIR.
This arrangement is employedwhen the useralready has a
high quality amplifier (usually 20watts or more if it is to
be worthwhile) which he desire to include in the system.
The preamp-
tone control combination including the reg-
ular CHI tone control feeds the
combined internal power
amplifiers; the preamp-tone control combination including
the regular CH2 tone control feeds out
through the CH2
TAPE OUT jack to an external power amplifier. The SER-
VICE SELECTOR switch on
the chassis must be set at the
COMbined position for this service in order to disconnect
the input of the CH2 power amplifier from the output of
the CH2 tone control and connects it instead to the input
of the CHl power amplifier, The CHI and
CH2 power
amplifiers are paralleled at the outputs
, as shown
, by an
external jumper connected between corresponding speaker
connection taps, The external
signal connection and the
speaker connections are shown in Fig,
2a. The
internal
arrangements in the HF-
81 at each of the positions of the
FUNCTION selector are
shown in Figs. 2b, 2c, 2d, 2e,
, and 2g, as an aid to
understanding the operation with
this arrangement.
CH. 1 LOW
LEVEL INPUTS
FIG.
MONOPHONIC
TUNER,
TAPE, TV
CH. 1 LOW
LEVEL INPUTS
FIG. Ig
MONOPHONIC PHONO
CH. 2 LOW
LEVEL INPUTS
CH. 1 LOW
LEVEL INPUTS
FIG.
CHECK AMPL.
CH. 1 HIGH
LEVEL INPUTS
CH.
TAPE OUT
SEP
CH.
TAPE OUT
CH. 1 HIGH
LEVEL INPUTS
CH.
T APE OUT
SERVICE SEL
SEP
~~~:MP
CH.
2HIGH CH.
LEVEL INPUTS
T APE OUT
TAPE
OUT
CH.
(f)
. I
::! I
:Q it
'" I
a I
"" I
EXT
~RNA BASIC
POWER AMPLIFIER
~ i
~ I
1___-
.INPUT
SPEAKER
CH 1
SPEAKER
CH.
SPEAKER
CH.
SPEAKER
CH.
CH.
* On integrated
amplifiers HF20, HF32 feed into
TAPE
OUTPUT lack; on HF521 feed into ELECTRONIC CROSS-
OVER INPUT jack,
after severing
connection between
ELECTRONIC CROSSOVER IN and OUT jacks.
FIG. 2a. SPEAKER & EXTERNAL
SIGNAL CONNECTIONs.
CH. 1 HIGH
LEVEL INPUTS
CH.
TAPE OUT
SPEAKER
CH.