Eico HF-81 User Manual page 2

general description
MODEL Hf -
DUAL 14 WATT HI-
STEREO AMP - PREAMP
GENERAL
The EICO Model HF-
81 is a complete high fidelity stereo-
phonic control center and a pair of 14watt amplifiers, all
on one chassis. With it you can select preamplify, and
control accurately any stereophonic source (tape, discs, or
broadcasts) and feed it through the
self-contained dual 14
watt amplifiers to a stereo pair of speaker systems.
When
you playa monophonic
source, the 14 watts available per
channe I adds up to a total of 28 watts for your two speaker
systems. If you desire,
both amplifiers can be connected
in parallel and driven byone preamp I
ifier-control section
whi Ie the other preampl
ifier-control section is free to drive
an external power amplifier. In this way your old ampli-
fier can be put to use in a stereophonic
system. Construc-
tion is of the "Iow silhouette
" type that permits you to
dispense with cabinetry if desired.
FEATURES
1. Separate low
level input in each
channel for mag.
phono, tape head, and microphone. Circuitry
carefully
designed to provide the high gain required by tape heads
and high quality, low output mag. cartridges without
hum
and noise problems. A front panel switch permits choice
of the proper NARTS tape head equalization for
either
7 1/2 & 15 or 3 3/4ips tape speeds.
2. Separate
high level inputs
for AM,
FM, and FM
Multiplex. Also two
auxiliary A inputs (one in each
channel) and two auxil iary B inputs (one in each channel).
Input Selector switch on front panel has positions for
feed-
ing FM tuner output to one channel and AM tuner to
other
, or
FM tuner to one channel and FM Multiplex
adapter output to other.
3. May be
used as either two independent amplifier-
preamplifiers, or one preamplifier-control section may be
set free to operate an external
power amplifier and the
other preampl ifjer-control section used to drive
both in-
ternal power
ampl ifiers
connected in parallel at
the
speaker connection terminals. A top -
of-chassis sl ide
switch permits choice of operation.
4. Ganged
level controls and a separate focus (balance)
control.
5.
Independent full-range bass and treble tone controls
in each channel. Tone
controls of the low distortion
variable cross-over feedback type.
6. Identical
Williamson type, push- pull EL84power am-
plifiers with high quality output
transformers.
7. Hum balance
control, panel-mounted fuse, pi lot lamp,
convenience outlets.
8. EICO "
low silhouette
" construction employing hori-
zontal chassis for proper layout and component separation.
Easy console installation,
if desired , with complete shield-
ing and adapatability to any panel thickness.
Copy,;ght I1d 1958 Electronic Instrument Company, Inc.