Specifications

general description
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
channeIadds up to a total of 28watts for your two speaker
systems. If you desire, both amplifiers can be connected
in parallel and driven
byone preampIifier-control section
while the other preampl ifier-control section isfree to drive
an external power amplifier. In this way your old
ampli-
fier can be put to use in a stereophonicsystem. Construc-
tion is of the "low 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, lowoutput mag. cartridges without hum
and noise problems. A front panel switch permits choice
of the proper
NARTB 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
1
MODEL HF-81
DUAL 14 WATT HI-FI
STEREO AMp·PREAMP
channel) and two auxiliary Binputs (one in each channel).
I
nout Selector switch on front panel has positions for feed-
npur serecror swiren on rronr panel nas polil I lun::o lUI ."'''' ... -
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 iFier-control section used to drive both
in-
ternal power amplifiers connected in parallel at the
speaker connection terminals. A top - of-chassis slide
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, pilot lamp,
convenience outlets.
8. EICO "low silhouette" construction employing
hori-
zontal chassis for proper layout and component separation.
Easyconsole installation, if desired, with complete
shield-
ing and adapatability to any panel thickness.
Copyr ight © 19 58 Electronic In strument Compan y, Inc .