PRELIMINARY! Be lure oil tube* are firmlyseated In their
sockets and that the tube shteldsare making good contact
with their bases. As Initial adjustments, set these controls
as follows: LEVEL at zero,LOUDNESS at ten, BASS at
zero. Turn the amplifier on by turning the TREBLE con-
trol clockwise from OFF and set It at zero Initially.
LISTENING TO PHONOGRAPH: Set the SELECTOR to
oneof the record equalization positions on the dial. Do-
ing so automaticallyselects thephonograph Input plugged
Into PHONO INPUT 1or PHONO INPUT 2. For help
In choosing the recording curve appropriate to any parti-
cular record, refer to thechart titled "RECORD EQUILh
ZATION SELECTION". When In doubtas to which equl II-
zaflon Is most appropriate, use RIAA, which Is the best
compromise for all records. Keep In mind that while the
positions offered caver most recording curves likely to be
encountered, additional separate and variable bass and
treble response adjustments are necessary for folly satis-
factory results. These may be necessary to compensate
for the over-all characteristics of your audio system (In-
cluding room acoustics). Inexact matching of the actual
recording characteristic by anyof the equalizations pro-
vided, and, aboveall, the particular tastes of the listener.
4
LEVEL &LOUDNESS CONTROLS: Simply stated, the
purpose of the LOUDNESS control Is to provide compen-
sation for the Increasing Inefflctencyof the human ear In
hearing bass and treble withdecreasingvolume level .The
LOUDNESS control, as It Is turned counter-clockwise
from maximum clockwise rotation, not only decreraes the
volume but Increasingly emphasizes the bass and treble
according to the Fletcher-Munsoncurves (curves developed
from astatistical study ofthis effect). An uncompensated
LEVEL control Is also provided to "set" the LOUDNESS
control for proper operation In any system, and also for
the purpose of adjusting the listening level when going
from quiet program material to loud program material or
the reverse without occasioning achange In the loudness
compensation. To "set" the LOUDNESS control at any
time, perform these operations In the order gjv^p to avoid
blasting or possibledamage to speakers of low power-hand-
ling capacity: a) Turn the LEVEL control to zero; b)
Turn the LOUDNESS control to ten; c) With high level
orchestral program material being fed to the amplifier from
your phonograph or tuner, advance the LEVEL control set-
ting until arelatively loud listening level Is obtained,
d) Turn down the LOUDNESS control until your normal
listening level Is obtained with the LEVEL control set as
just described. Proper loudness compensation should now
be obtained at any listening level adjusted to with the
LOUDNESS control .The same reference LEVEL control
setting will be suitable for both phonograph and tuner list-
ening If the volume control of the tuner has been adjusted
as described In the "High Level Inputs" sub-section of the
"Electrical Connections" section. When selecting Inputs
which do not have level ad|usts, such as tv or acrystal
cartridge connected to the AUX. Input, It may be desir-
able to set the LEVEL control to zero beforehand and then
bring up the LEVEL control to obtain the desired list-
ening level to avoid blasting. Note that the LEVEL con-
trols affects the output to tape recorder available at the
TAPE OUT jack but that the LOUDNESS control has no
affect on this output.
BASS CONTROL: The plus sign on the right side of the
dial Indicates that clockwise rotation from the mid-point
(0) Increases (boosts) ban response; the minus sign on the
left side Indicate that counter-clockwtse rotation from the
mld-potnt decreases (cuts) ban response. There Is no In-
teraction with the TREBLE control. Start all adjustments
with this control set at the mid-point (0^which Is called
the "flat" position since ban response Is neither cut nor
boosted at this setting. This control does affect theout-
put to atape recorder from the TAPE OUT jack to permit
"touching up" of the record equalization or reducing the
effect of low frequency disturbances when recording on
tape. Set It at zero If no effect during recording Is de-
sired.
e
TREBLE CONTROL: The plus sign on the right side ofthe
dial indicates that clockwise rotation from the mid-point
(0) Increases (boosts) treble response; the minus sign on
the left side Indicates that counter-clockwise rotation
from »hs mid-pointdecreases (cuts) treble response. There
Is no Interaction with the BASS control. Start all adjust-
ments with this control set at the mtd-potnt (0),
which Is
called the "flat" position since treble response Is neither
cut nor boosted at this position. This control does affect
the output to atape recorder from the TAPE OUT jack to
permit "touching up" of the record equalization or reduc-
ing the effectof high frequency disturbances when record-
ing to tape. Set It at zero If ho effect during recording Is
desired.
LISTENING TO TUNERS, TV, TAPE RECORDERS: With
the SELECTOR switch set at TUNER, TV, TAPE or AUX-
ILIARY, the corresponding high level Input from aradio
tuner, tv, tape recorder, second tuner or crystal cartridge
will feed through the amplifier. Adjustmentof the volume
control on eachsource Is discussed In the "Electrical Con-
nections" section under "High Level Inputs” and again
under "Lever &Loudness Control" In this section.
MAKING RECORDINGS: Tape, wire, or disc recordings
'"ay be made by connecting the recorder to the TAPE
OUTPUT jack. See "TAPE OUTPUT" under ELECTRICAL
CONNECTIONS" and the "BASS CONTROL" and "TRE-
BLE CONTROL” operating Instructions. With the output
of the recorder connected to the "TAPE INPUT" jack,
turning the SELECTOR switch to TAPE readies the ampli-
fier for playback of the recording.
RECORD EQUALIZATION SELECTION
Recordsare made with boosted volume In the treble range
to mask surface noise and reduced volume In the bass
range to conserve groove space and reduce distortion.
As there was no universally accepted standard of treble
boost and bass cut In recording before Spring 1954, re-
cords of which the masters were made before this date
may require any one of several different equalizations
