2A3 SET integrated amplifier

2A3 SET integrated amplifier
tube integrated amplifier
Lyrita Audio
L - 458, Sarita Vihar
New Delhi 110 076
Tel : 011-4140 1143
Lyrita Audio
Input tube
Russian 6N1P (1 nos)
Driver tube
Russian 6N6P (1 nos)
Output tubes
Shuguang 2A3C (2 nos)
Rectifier tube
Russian 5Z4C (1 nos)
Within this period, Lyrita Audio will repair the amplifier
without charge, provided that failure was not due to
Power Output
3 watts per channel into 8 ohms
Frequency Response
40 Hz to 20 kHz
A separate guarantee card is not issued with this unit. The
guarantee period begins on the day you take delivery.
Distortion (THD)
less than 1%
CD, Tape, Tuner
Mains Power
230 V, 50 Hz, 250 W (max)
Size W x D x H
360 x 520 x 200 mm
18 kg
This amplifier is guaranteed against any defect in material
and workmanship for a period of two years from the date
of purchase. Tubes are guaranteed for thirty days.
Serial No. ________________
The amplifier should be placed as close to the
loudspeakers as possible. This will allow the connections
to be made with short speaker cables. It is advisable to
keep the additional impedance seen by the amplifier as
low as possible. The best way to do this is to keep the
speaker cables short.
The 2A3 SET is a low power tube, stereo integrated amplifier,
offering superb reproduction of sound.
Good ventilation should also be provided around the
amplifier. The tubes generate a fair amount of heat, and
natural ventilation is necessary to dissipate this heat to the
surroundings. The amplifier chassis will get warm, but
should still be comfortable to touch.
The design is a single-ended, directly heated triode (DHT)
tube amplifier. The entire signal in each channel is handled
by a single output tube, making this class A operation. All
wiring is point-to-point. The tube input stage is capacitor
coupled to the driver stage, which in turn is coupled through
an interstage transformer to the tube output stage. The output
stage uses a custom designed audio output transformer. No
global feedback is used.
Always place the amplifier on a firm, smooth surface.
The 2A3 SET amplifier accepts three line level source inputs.
The signal path is kept as simple and as short as possible, to
preserve the integrity of the music signal.
Tube amplifiers need a load connected to their output.
Always connect the speakers before operating the
The power supply has an oversized transformer, to provide
good regulation for the supply voltages. Tube rectification is
used. Each stage of the high voltage supply is independently
filtered through chokes. Individual filament transformers are
used for low noise operation.
To power on:
Flip the power switch DOWN. LED glows ‘Green’.
Wait 1 minute, for the tubes to heat up.
The 2A3 SET is housed in a naturally finished solid
sheesham cabinet. The design elegantly showcases the
beauty of the tubes.
When making or breaking any connections, always turn off
the power to the amplifier first, so that no hum or
transients are transferred to the speakers.
When sitting down to a listening session, it is a good idea
to let the system warm up for a half-hour. This stabilizes
the circuitry, and makes it sound better.
! Warning : In operation, this amplifier has high
voltages. Always switch off, and unplug the amplifier
from the mains supply before working on it. Wait for 5
minutes for the high voltages to die down, before
opening the amplifier!
Mains supply connection is through a detachable power
cable with an IEC-type connector. The mains power
switch is mounted on the front panel of the amplifier.
All input signal connections are made to RCA sockets on
the back panel of the amplifier. These are user specified,
for line level sources only.
The speaker output sockets accept banana jacks only.
The norm here is Red for signal and Black for ground.
Maintain the colour code when connecting to the
loudspeaker, so that the speakers operate in phase.
The amplifier is protected against overload by fuses at
three points. The mains supply fuse is mounted on the
rear panel and is easily accessed from the outside.
Inside the amplifier are two fuses on the high voltage
supply. These are mounted on the inside panel above the
power supply capacitors. To reach the internal fuses,
remove the back top plate of the amplifier.
Mains supply fuse
2 A, 250V (RQB 2000)
High Voltage supply fuse 200mA, 250V (RQB 200)
100mA, 250V (RQB 100)
On operation of the amplifier, if the fuses do blow, check
all possible causes before replacing the fuses. If any
doubt remains, contact Lyrita Audio for servicing.
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