Thrax Audio Spartacus 300 User manual

Spartacus 300
Mono Power Amplifier
by Thrax Audio
Operating Manual
Manual issued 05/05/2020
CAUTION
THE UNIT CONTAINS NO USER SERVICEABLE PARTS. DO NOT REMOVE THE COVERS. LETHAL
VOLTAGES ARE PRESENT WITHIN THE CHASSIS.
NEVER OPERATE THE AMPLIFIER WITH THE CHASSIS COVERS REMOVED.
DO NOT OPERATE THE UNIT IF WET OR NEAR WATER.
THE AMPLIFIER IS FAIRLY HEAVY. BE SURE TO USE PROPER LIFTING TECHNIQUES TO AVOID
BACK STRAIN AND INJURY. BE CERTAIN TO INSTALL IT IN A SECURE LOCATION FROM WHICH
IT CANNOT FALL OR TIP OVER.
WARNING: The tubes become very hot during operation. Take care to keep them out of
reach, especially around children and pets, as they become extremely hot and may
cause serious injury. Never touch a tube if the glass is broken. The internal structures carry
high voltage and could present a serious, possibly lethal shock. If a tube breaks, unplug
the amplifier and wait 30 minutes, then remove the tube. Keep flammable objects away
from the amplifier.
TIME SPENT FAMILIARIZING YOURSELF WITH THIS MANUAL WILL BE WELL REWARDED.

1. Important Safety Instructions …...................………….................................... 3
2. Introduction ………........................................................................................… 4
3. Specifications ……........................................................................................… 4
4. Unpacking and Installation
- Unpacking ……....................................................................................… 5
- Installation ……....................................................................................… 6
5. Front Panel ….............................................................................................… 6
6. Back Panel ……..............................................................................................… 7
7. Operation ………...........................................................................................… 8
8. Tube replacement .................................................................... 8
CONTENTS
2

READ ALL INSTRUCTIONS: All the safety and operating instructions of your Thrax Audio
equipment should be read before power is applied to the equipment.
RETAIN OWNER'S MANUAL: These safety and operating instructions should be retained
for future reference.
HEED WARNING: All warnings on the unit and in the operating instructions should be
adhered to.
FOLLOW INSTRUCTIONS: All operating and use instructions should be followed.
CLEANING: Unplug the unit from the wall outlet and leave for at least 30 min. - make sure
the unit is not hot before you start cleaning. Use dry or damp soft cloth to clean the
surfaces. Do not use sprays, abrasive or corrosive cleaning products.
VENTILATION: Do not block any ventilation openings. Do not install near any heat sources
such as radiators, heat registers, stoves, or other apparatus (including amplifiers). The unit
should not be installed in a built-in location such as a bookcase or rack unless proper
ventilation is provided.
GROUNDING: Do not defeat the safety purpose of the grounding-type plug. A
grounding-type plug has two blades and a third grounding prong. The third prong is
provided for your safety. If the provided plug does not fit into your outlet, consult an
electrician for replacement of the obsolete outlet.
POWER CORD PROTECTION: Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles and the point where they exit from the
apparatus.
LIGHTNING: Unplug this apparatus during lightning storms or when unused for long
periods of time.
SERVICING: Refer all servicing to qualified service personnel. Servicing is required when
the apparatus has been damaged in any way, such as if the power-supply cord or plug is
damaged, liquid has been spilled inside the appliance or it has been exposed to
moisture, the appliance does not operate normally, or has been dropped.
DO NOT OPEN THE CABINET: There are no user serviceable components inside this
product. Opening the cabinet may present a shock hazard, and any modification to the
product will void your warranty.
WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain
or moisture.
IMPORTANT SAFETY INSTRUCTIONS
3

The Spartacus 300 mono power amplifier is the world's finest audio amplifier and an
absolutely unique component. Its unusual topology, premium parts, and flexibility make it
a pleasure to hear and operate. Spartacus is a two stage shunt regulated Directly
Heated Triode power amplifier.
Features
1 XLR balanced input
50W pure 300B amplification
dB/Watt meter display
1 pair of Binding Posts
Inside you get
Tube rectified choke input PSU feeding film reservoir capacitors. Then each stage has its
own constant current fed shunt regulator.
The input/driver stage is a single-ended directly heated triode with grounded cathode
and fixed bias and loaded with a rather special Japanese transformer.
The output stage is two pairs of directly heated triodes operating independent windings
on the same Japanese Permalloy core transformer biased through innovative servo
circuitry. The heating of all the filaments is done through voltage controlled current
sources.
The case is made from plates of different thickness machined solid aircraft grade
aluminium.
INTRODUCTION
4
• Input
- 1 balanced XLR connector
• Output ……………….................................................….. up to 50W in 4 Ω or 8 Ω
• Power supply ……………….....................................................…….. 115 or 230 V
• Power consumption …………….......................................................…….. 380W
• Dimensions ……………….................................... …….. 440W x 540D x 300H mm
• Weight ………………............................................................................…….. 55Kg
• Finish ……..........................................…….. Black or Silver anodized aluminum
• Tube compliment :
- 1x EML300B input
- 4x EML300B amplification
- 1x EML300B shunt regulator
SPECIFICATIONS

Fit each tube into the matching socket firmly, noting the location of holes in the socket
and pins of the tubes, making sure that its pin pattern corresponds to the holes in the tube
socket.
When inserting and removing tubes, handle them by their bases, not by their glass bulbs.
WARNING: Do not allow anything to touch the tubes in normal operation - they become
very hot. Make sure to keep everyone, especially children and pets, away from the tubes
which become extremely hot and may cause serious injury. Never touch a tube if the
glass is broken. The internal structures carry high voltage and could present a serious,
possibly lethal shock. If a tube breaks, unplug the amplifier and wait 30 minutes, then
remove the tube. Keep flammable objects away from the amplifier.
Unpacking
All Thrax Audio shipping boxes have been specially designed to protect their contents
and special care has been taken to prevent damage under normal shipping conditions.
Mishandling should be evident upon inspection of the shipping container. Carefully
remove your new component from its packing and examine it closely for signs of shipping
damage. We strongly recommend saving all original packing to protect your
component from damage should you wish to store it or ship it at a later date.
Spartacus is shipped with protective polyethylene foam around the tubes. You will need
a 2.5mm hex key to remove the top panel and foam - make sure all the tubes are firmly in
place before replacing the panel.
UNPACKING AND INSTALLATION
5
Step 1: Take the top panel off
Step 2: Remove protective foam
Step 3: Make sure tubes are firmly in place

• Provide adequate ventilation. Do not operate on carpet or any other surface that
might block air flow. The chassis will become warm in normal use!
• Do not allow the chassis to touch any metal parts, such as the frame of an equipment
rack. This might create a parallel ground path that could degrade the sound of your system.
• Input connection is via XLR jacks.
• Connect the input and speaker cables.
• Connect the power supply to the power source indicated on the voltage selector
card (visible by the main fuse), either 115 or 230 volts AC. You may select what voltage to
use by means of the removable selector card located behind the fuse in the power
connectors. Remove the card and reinstall so that the desired voltage may be read; be
certain to change the fuse to the correct value. Connect the power supply to the power
source indicated on the rear panel. Avoid power conditioners that float the ground pin.
ALWAYS connect power cord to component before plugging it into an AC outlet, and
make sure that unit's power switch is set to the "OFF" position before making the final
connection. For best performance, try to route the power cord away from signal cables.
• Power requirements are approximately 380 watts per channel. Pay close attention to
power quality, and be aware that different power cords can alter the sound.
INSTALLATION
6
"ON/OFF" Sensor
Tap the front panel to switch the unit on and off. See OPERATION SECTION for details.
FRONT PANEL
∞0.002 0.1 0.2 1.5 12 50 100
∞-42 -33 -24 -15 -6 0
WATTS
dB
THRAX

7
BACK PANEL
Input
A XLR jack is provided for balanced connection to a pre-amplifier.
NOTE: Do not remove and connect input cables or speaker cables while the amplifier is
running, you risk damaging your loudspeakers or amplifier. Do not operate the amplifier
without a loudspeaker.
Speaker output
The speaker cables connect to the Speaker Connectors. Either banana jacks, bare wires
or spade plugs can be used. If bare wire is used, be careful that no stray strands get loose
and cause a short-circuit. The “Common” or “Ground” lead connects to the black jack.
The “Hot” lead goes to the red jacks. Bare wires and spade plugs must be tightened by
rotating the ratchet screw clockwise.
A/C Fuses
There are fuses located in the IEC power connector on the back panel. For 220 volt
operation 6.3 amperes "slow blow" fuses are used. For 110 volt operation the fuses should
be 10.0 amperes. If power does not come on, contact your authorized service
representative or consult the factory for more information.
300
INPUT
OUTPUT
TRIGGER
IN
Speaker Output
(Binding Posts)
XLR Input
A/C Fuses

8
For initial power up press the main switch located on the back panel.
Tap the front panel to turn the amplifier on. The meter on the front will light up.
To turn the amplifier off tap the front panel again. If you are not going to use the amplifier
for a long period we recommend turning it off using the power switch on the back panel,
to save power.
As with all high fidelity products, the sound characteristic changes somewhat as it warms
up. Best sound will be achieved after about 15 minutes of operation.
Any time that the Spartacus power amplifier has not been used for a few weeks the sound
may be different. This is also normal for high resolution audio equipment. Optimum sound
should return after a few hours of operation, preferably with an audio signal.
Note that although your Thrax Audio System has been run for 72 hours at the factory, it will
continue to "break in" for approximately 150 hours. Also be aware that many components
display the need for a new break in period after being transported in unheated cargo
aircraft.
OPERATION
Tube replacement
300B’s are some of the sturdiest long-life tubes on the market and would normally last 10
years or more, but in case of tube failure there would be a very noticeable deterioration
in sound quality and should be replaced immediately - we strongly advise you to order
replacement tubes from your Thrax Audio dealer as soon as possible.
TIPS

9
NOTES