Thoebe Servo-Loop Preamplifier Owner's Manual

Your Thoebe Servo-Loop Preamplifier derives
performance from the technology and experience Great American
Sound Company engineers have gained from the development of
Thaedra. To insure equal performance, Thoebe uses
circuitry (i.e. phono and line amp cards).

is

The result
equipment.

It must be remembered that Thoebe is a complex, highly sophisticated
example of electronic equipment and some common sense must be
exercised when operating it.

a welcome addition to our growing line of Audiophile

its

"State of the Art"

identical

active

INTRODUCTION

1.

When Thoebe
seconds before anything will be heard. DO NOT attempt to turn up
gain during this period. When the relay closes, you may be delivering
in excess of
probably will not save your speakers (or ears) from permanent
damage.

2.

Turn level down between musical or source selections and when
turning the power on or off.

3.

Thoebe runs warm! Make sure it has adequate ventilation.

WARNING:

appliance to rain or moisture.

is

turned on, there will be a time delay of several

10V

RMS signal to amplifier, your reaction time

To prevent fire or shock hazard, do not expose this

UNPACKING

Immediately upon receiving Thoebe, inspect the carton for evidence of
mishandling during shipment. Then, carefully unpack the amplifier

and inspect it for any sign of damage. Please save the shipping carton
and all the associated packing materials for future use. The shipping

materials have been carefully designed to transport your Thoebe with a

minimum of disturbance.

must

Shipment to the factory for any purpose
carton and packing. If the original carton
G.A.S. Company for replacement.

NOTE: If damage has occurred in shipping, please contact your dealer

immediately.

THOEBE is designed primarily for mounting on a shelf. An optional

is

wood cabinet

available.

be made in the original

is

lost or damaged, contact

Where THOEBE
cutout must be provided.

Allow enough space and/or holes for proper ventilation
cjrcumstances should the ventilation slots on the top and bottom of the
chassis be blocked.

RACK-MOUNTING: A rack mount panel version of THOEBE
available from your dealer, for use with the standard,
rack. Be certain that the insulating plastic bushings (provided with the
panel) are used under each mounting screw to provide electrical

isolation of the unit from the metal rack.

CAUTION: Under no circumstances should you mount the unit in

is

to be inserted into a panel,

vertical position. This will cause overheating of the unit.

a

17

inch by

-

19

5-114

Under no

inch metal

inch

is

a

With the power switch in the OFF position, plug the line cord into any

105-125V. 50 or

other connections have been completed.

60Hz

outlet. Do not turn on the power switch until all

CONVENIENCE OUTLETS:

Refer

to

pictorial

Four convenience outlets have been provided on the rear panel to
power associated components in your system. Of these outlets, three
are controlled by the front panel onloff switch
use with tape recorders, and medium powered amplifiers, (i.e. Son of
Ampzilla). The one remaining outlet
turntables that have built-in power switches mechanically linked to
disengage their rubber idler wheels.

NOTE: We do not recommend using these outlets with high power

amplifiers. AMPZILLA cannot be plugged into these outlets.
Under no circumstances should
be used to plug the AMPZILLA line cord into one of Thoebe's
convenience outlets! To keep within
AMPZILLA must be powered directly from
the third wire can be grounded (No ground wire
recommended for Thoebe).

A

(1000

Watts total) for

is

unswitched and may be used for

a

three-to-two prong adapter

its

warranty provisions,

a

wall outlet where

is

required or

PRE-PREAMP POWER SUPPLY

Located on the back panel of Thoebe

+

connector. This supplies

28V for using Goliath pre-preamp.

JACK

is

a power supply output

MAlN OUTPUTS

CONNE

FSi&

Refer to pictorial

Two stereo sets of audio output jacks are provided for connection to

power amplifiers or electronic crossovers. Special audio cables with
gold-plated contacts have been supplied for this purpose. The
gold-plated contacts have the low resistance necessary for a reliable

interconnection throughout the life of the equipment; additionally, the

high quality coaxial cable with braided shield guarantees highest

possible isolation from external electrostatic and electromagnetic

radiation.

The stereo output jacks are labeled MAlN 1 and

identical and turn on is time-delayed by a relay.

Make certain that the cable contacts are fully engaged so that no loss of
circuit ground exists when the equipment is turned on. A very loud

hum or buzz will be heard if this condition does occur.

The source impedance of the two main outputs are each 60 Ohms, low
enough to permit the use of shielded, interconnecting cables up to 100
feet in length.

A

2.

They are both

TAPE OUTPUTS

Refer to pictorial

Two pairs of stereo output jacks are provided on the rear panel for
connection to any tape recorder having a minimum load impedance of

5K

Ohms or higher. Since the source impedance of each

cables up to 100 feet may be used without high-frequency attenuation.

Unlike the main' outputs, the tape-output signals are independant of

balance, volume and tone control settings and are at a level equal to the

source-input level (Tuner, Aux, Etc.)

NOTE: The TAPE OUT stereo phone jack on the front panel has been

provided for tape-copying purposes and may always be utilized
in the same manner as the rear outputs. (Refer to the
paragraph on TAPE COPYING).

A

&

B

is

500

Ohms,