Thrax Audio Teres Stereo Power Amplifier Instruction Manual
- June 9, 2024
- Thrax Audio
Table of Contents
Thrax Audio Teres Stereo Power Amplifier
Operating Manual
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: Do not allow anything to touch the tube in normal operation – it becomes very hot. Take care to keep everyone, especially children and pets, from being able to reach and touch the tube, which becomes 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.
IMPORTANT SAFETY INSTRUCTIONS
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 before cleaning. The unit
should be cleaned only as recommended by the manufacturer.
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.
INTRODUCTION
Teres is a two-stage hybrid power amplifier, a true high-end audio product, a
bridge between solid-state power and vacuum tube finesse and resolution. The
input stage employs a 6N6P tube for super low noise and extreme linearity. The
output stage uses JFET/MOSFET cascodes of the same polarity with inverted
phase and floating power supplies.
Signal path simplicity and zero feedback design brings unprecedented clarity
and tone richness with power to spare.
Features
2 inputs – one unbalanced on RCA and one balanced on XLR “Trigger in” pairing
with the Thrax Dionysos preamp.
Inside you get
Separate constant current PSU for the input tube and separate PSU for the
output stage. The input stage uses a property choke input rectifier and shunt
regulator power supply solution for super low noise and stability. The power
supply uses a new breed of rectifier diodes made of a new material called
Silicon Carbide that have no reverse current and switching losses.
SPECIFICATION
- Inputs
- 1 pair unbalanced RCA connectors
- 1 pair balanced XLR connectors
- Output ……………………………………………………………….. 150W/8 Ω, 200W/4Ω
- Power supply ……………………………………………………………..…….. 115 or 230 V
- Power consumption …………………………………………………………….…….. 250W
- Dimensions …………………………………………………….. 230W x 400D x 340H mm
- Weight ………………………………………………………………………………….…….. 35Kg
- Finish ……………………………………………….. Black or Silver anodized aluminum
- Tube compliment :
- 1x 6N6P amplification
UNPACKING AND INSTALLATION
Unpacking
Teres is shipped with the vacuum tube installed. Unpack carefully, keep in
mind the unit weighs 25 kg. 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.
Installation
- 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 single-ended RCA jacks or XLR jacks (unbalanced or balanced sources).
- Connect the input and speaker cables.
- Connect the power cable from the power supply to the power amplifier.
- 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 the 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 250 watts per channel. Pay close attention to power quality, and be aware that different power cords can alter the sound.
- Set the input type switch to XLR or RCA, to match the source and cables.
WARNING: Do not allow anything to touch the tubes in normal operation – they become very hot. Take care to keep everyone, especially children and pets, from being able to reach and touch 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.
FRONT PANEL
“ON/OFF” Button
- Switches the unit on and off. See OPERATION SECTION for details.
LED Indicator
- Red light indicates stand-by mode, green light – operation mode. Green light flashes during warm-up.
BACK PANEL
Inputs
RCA (single ended) connection normally is made to the RCA jack. The “INPUT
SELECT” switch is set to “RCA” (up) position.
A XLR jack is provided for balanced connection to a pre-amplifier. The “INPUT
SELECT” switch should be set to the “XLR” (down) position.
NOTE: Do not remove and connect input cables or speaker cables while the
amplifier is running. Doing so may damage 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 and Mains switch
There are fuses located in the IEC power connector on the back panel. For 220
volt operation 4 amperes “slow blow” fuses are used. For 110 volt operation
the fuses should be 8 amperes. If power does not come on, contact your
authorized service representative or consult the factory for more information.
Trigger In
Connect the Trigger Out of your preamp to the Trigger In and Teres will turn
on and off parallel to your preamp.
OPERATION
For initial power up press the main switch located on the back panel. The LED
on the front panel lights red indicating the unit is now in stand by mode.
To switch the power amplifier on press the “ON/OFF” button located on the
front panel. The LED indicator flashes green whilst warming up for about 2
minutes. Red LED turns to green when your Teres is ready for use.
To turn the power amplifier off press the “ON/OFF” button. However, 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.
The trigger in feature is to be used with the Thrax Dionysos preamplifier.
Simply connect them using the standard aux jack inputs, and the Teres will
turn on automatically when the preamp is powered on.
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 Teres 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.
TUBE REPLACEMENT
Your Teres comes with the tube pre-installed. The 6N6P tube is a durable
Russian military-grade tube with a working time minimum of 2 000 hours. When
tube replacement is due, we strongly advise you to order replacement tubes
from your Thrax Audio dealer, before the sound quality starts to deteriorate.
Before replacing the tube, all power must be turned off. Unplug the power cord
from the wall, and remove all audio interconnect cables. Wait 15 minutes
before removing the tube.
When removing the tube, handle it carefully, with minimum twists.
Install the new tube firmly in the socket, noting the location of holes in the
socket and pins of the tube, making sure that its pin pattern corresponds to
the holes in the tube socket.