Lyrita Phono MC User manual

Lyrita Audio
L - 458, Sarita Vihar
New Delhi 110 076
Tel : [phone]
email:viren.bak[email protected]
www.lyrita-audio.in
Phono MC
tube preamplifier
Manual
Lyrita Audio

Guarantee
This preamplifier 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.
Within this period, Lyrita Audio will repair the amplifier without
charge, provided that failure was not due to misuse.
A separate guarantee card is not issued with this unit. The
guarantee period begins on the day you take delivery.
Model No. _________________
Specifications
Tubes, phono Russian 6S3P (437A)
Russian 6N2P (ECC83)
Russian 6N6P
Tube, rectifier Russian 5C4M (5Z4G)
Frequency Response 20 Hz to 20 kHz
Distortion (THD) less than 1%
Input Phono in
Output Phono out
Mains Power 230 V, 50 Hz, 150 W (max)
Size W x D x H 360 x 400 x 130 mm
Weight 10 kg

Operation
With tube rectification, the high voltage ramps up slowly.
The power switch is a 2-position switch.
 Up position is power ‘OFF’.
 Flip the power switch Down to turn ‘ON’.
The green LED lights.
The preamplifier will power up in about 15 seconds.
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.
Description
The Phono MC tube preamplifier is a high gain dedicated
preamplifier for LP record replay.
It accepts an input from a low output Moving Coil or Moving
Magnet cartridge. The correct loading is applied for the type
of cartridge used, and can be customized for a specific
cartridge.
The overall design is simple and direct. The first stage is FET
coupled using a high transconductance tube, the Russian
6S3P (437A). The second gain stage uses the Russian 6N2P
(ECC83). Passive RIAA equalization is applied between
these two active gain stages. A subsequent gain stage using
the Russian 6N6P tube provides high current drive and a low
output impedance.
All wiring is point-to-point. All gain stages operate in Class A
mode. No global feedback is used.
The power supply has separate EI-Core transformers, for the
heater supply to the tubes, and for the high voltage supply to
the various stages. Each stage of the high voltage supply is
independently filtered through chokes and RC filters. A tube
rectifier is used.
The Phono MC tube preamplifier is housed in a naturally
finished solid sheesham cabinet.

Connections
Power
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.
Signal — Phono In and Phono Out
The input and output signal connections are made to the RCA
sockets on the back panel of the amplifier.
Installation
Good ventilation should be provided around the preamplifier.
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.
Always place the amplifier on a firm, smooth surface.
Fuses
! Warning : In operation, this preamplifier has very 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!
The preamplifier is protected against overload by a fuse at
one point only. This is the mains supply fuse, mounted on the
rear panel and is easily accessed from the outside.
Mains supply fuse 1 A, 250 V (RQB 1000)
On operation of the preamplifier, if the fuse does blow, check
all possible causes before replacing the fuse. If any doubt
remains, contact Lyrita Audio for servicing.