Eico HF 20 Owners Manual

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E I. E c T I 0 II I c
3300 NORTHERN

MANUAI. ' '
HEM-I . .

HIGH FIDELITY AMPLIFIER

MODEL

IlF-ZII

INSTRUCTION . o

INSTRUMENT CO. INC.
.BLVD L. I. CITY 1, N. Y.

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" MODEL'IIFZO
HIGH FIDELITY AMPLIFIER

The EICO Model 20 is the result of a program aimed at
bringing together in one integrated unit the finest pre-
ampliqu control, and power amplifier circuitry. Please
read the following instructions before installing or using
the amplifier, particularly if you are not thoroughly fa-
miliar with equipment of this type. You will learn how
to install the arnplifierproperlyond how the controls and
facilities should be used to obtain the best results.

You may skip over the installation section if your ampli-
fier is installed by a competent techniciat, but this
section contains important specific instructions and a
mounting templatewhich should be made available to the
person performing theinstalletion. in any case, it is im-
portant that this manual beretalned since it contains es-
sential servicing information which will be needed by
any person who undertakes to service the amplifier.

DESCRIPTION

The Model 20 consists of o highquality pump-equalizer
and control section plus a 20' watt Ultra-LinearWilliam-
son type power amplifier. Details are as follows:

THE PREAMPLIFIER'EOUALIZER CIRCUIT possesses ex-
tremely low distortion due to equalization entirely by
feedback-it was chosen deliberately because of its obi lity
to match the low-distortion performance of the Ultra-Lin-
ear Williamson-type amplifier circuit. it has a balanced
selection of alizationswhich, together with the wide-
rangebass an treble tone controls, permits correctcom-
ponsation for practically any mlcrogroove or 7B recording
characteristic, foreign or domestic.

FOUR HIGH LEVEL lNPUTS AND 2 LOW-LEVELINPUTS
(i switch position) enable the '20 to accommodate TV,
tape recorder, AMFM tuner, and crystal cartridge (or
separateAMand FM tuners), as well as any leading mag-
netlc or FM pickup without the necessity of component
changes. A low impedance, logically-placed tape out-
put lock is a valuable convgnience for those owning or
planning to own a tape recorder.

THE BASS AND TREBLE TONE CONTROLS areof the new
feedback type for exceptionally low distortion and wide
frequency range. Theydo not affect the volume or Inter-
act with each other-providing the easiest possible con-
trol settings. As turnover on both ends varies with the
amount of boost and attenuation, boost or cut at the ex-
tremes of the audio range is possible without affecting the
mid-range.

THE LOUDNESS .CONTROL, a Centralab Compentrol,

raises or lowers volume in strict accordance with the ac-
cepted Fletcher-Manson ear-response curve. Operation
together with front panel level control provided is widely
heldas oneof theth flexible and sensiblearrangements.

THE POWER AMPLIFIER: The power amplifier in the '20
is of theUltro-LlnearWiIIiamsontype. its superb perform-
ance characteristics are augnented by the high-quality
output transformer, which is conservatively rated at 25

watts .
SPECIFICATIONS

Power Oumt: 20 watts (34 watts peak)
lM Distortion S60 8 6000cfl4zi, 20W): 1.3%

Mid-Band Harmonic Distortion 20!}: 0.3% .

Power Ram (20W) +0, 'i db 20 to 20,000cps
+0, -3db i0 r. 40,000cps

Fragencz Ream (1am: +0, "1 db l3'35,000cps
+o,-3db 760,000».

Mm: 7:1
lpxerse Fflback; Mdb

MW: 4. 3. and 16 ohm

1w Boss: 15db boost or cut at 50cm
Treble: i5dbboostorcut at lOkc

Pho E alxati s RIAA, Columbia, London, Euro-

poan 78, American 73.
Sensitivity: Mag. Phono_0'.094V rtns (atl kc)
for 20W output
Tuner, etc.-O..4V runs for ZOWoutput

*1 Hum s Noise: Mag. rm"_ was below saw
Tuner, etc. ._ 75db below 20W

includes iodb boostat60cps dueto RIAA compensation.
Maximum gain and tone controls set at flat positions.
flower Ling lemngnm i05-i25 volts, 50/60cps A_C_
only.
Mom: 100w?"
flu; 8 V2" high, 15" wide, i0 deep
Main; 24 lbs.
insulation
I. GENERAL FACTORS
a) HEAT DISSIPA'I'ION (VENTILATION): In common
with other electronic equipment, the Model 20 produces
a great deal of heat in normal operation. Unless contin-
uous and adequate air flow Is obtained around the heat

producing elements, these elements will ever-heatand
their useful life'will be greatly curtailed.