lab12 Suara User manual

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Owner’s Manual
suara
Parallel tubes 2 x 50W Class A Power Amplifier
www.lab12.gr
manual v1.0

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Lab12 suara 2 x 50W Class A Power Amplifier
Table of Contents
It is yours (page 3)
Features (page 4)
Installation & Placement (page 4)
Suara Tubes Position (page 5)
Front Panel (page 6)
Rear Panel (page 7)
Main connections (page 8)
Bias Setting (page 9)
For the safety of your equipment (page 9)
Specifications (page 10)

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Lab12 suara 2 x 50W Class A Power Amplifier
IT IS YOURS!
Thank you for selecting the Lab12 suara, an audiophile Parallel tube Class A power amplifier. Every
component on it is designed to provide smooth and untreated sound. It is a full tube amplifier with 2x
6n1p, 2x 6n2p NOS Russian driver tubes and 4 x KT150 on power stage. Suara can cooperate gratefully
with any preamplifier on the market and it is the perfect match for Lab12 pre1. Suara has the ability to
nail you down on your couch and make you listen all your music collection again. 50 watt of power for
any pair of speakers is available but the most remarkable point is that you will receive a fluid, wide and
addictive consonant sound with any choice of music style. All components are carefully chosen after
hours of listening and testing, while paying great attention to every detail affecting the final outcome. As
every Lab12 device, suara has an ultra-solid construction with handcrafted finishing, anodizing aluminum
face plate and retro analogue V/U meters.
Do not forget that your suara is totally handcrafted with perfectly matched parts of the finest selections.
You have to know that to reach the optimal performance, your suara needs at least 200 hours of
listening. In this time all components go from “burn in” period to stable.
Before setting up your new suara, we encourage you to read this manual thoroughly to properly
acquaint yourself with its features. We love music and audio devices and we have built your new device
with emotion and personal treatment.
The information contained in this manual is subject to change without notice. The most current version
of this manual is available on our official website at http://www.lab12.gr

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Lab12 suara 2 x 50W Class A Power Amplifier
Features
•6550, KT88 compatible (KT150 from factory)
•4x KT150 matched tubes
•Easy Manual Bias Adjustment on the back plate
•Triode / ultra linear selector switch
•Handcrafted custom audio grade transformers
•No feedback design
•Special audio grade matched parts in every stage
•SRSG® implementation
•Fine symmetry® implementation
•Analog retro nissei VU meters
•5mm aluminum face panel with luxury painting
•Five years guarantee
Installation & Placement
The Lab12 suara should be placed on a solid, flat surface.
You should avoid placing it near a heat source as this could compromise the suara’s performance and
reliability.
Carefully put the tubes in dedicated sockets. Make sure that tubes are perfectly snap into sockets. See
bellow page.
Due to high power tubes design, suara’s chassis could be hot so you should never place another hot
component directly near this device. Make sure that the device has enough space to ventilate.
Tubes will be hot, this is normal. Be careful not to touch the tubes during the operation to avoid any
injuries.
Take care of the finest luxury finish of front panel with a soft cloth.

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Lab12 suara 2 x 50W Class A Power Amplifier
Suara Tubes Positions
Insert the tubes carefully in each position. All of the tubes are marked with the position number was
placed during calibration and factory burn in of suara. All in box tubes are perfectly matched during
calibration to achieve a perfect balanced operation.
Suara Top

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Lab12 suara 2 x 50W Class A Power Amplifier
Front Panel
Suara Front pane l
At front panel you will see three indication LEDs and two VU meters.
The three LEDs (C) indicate that the device is powered on.
To the left of 3 LEDs you see a retro analog VU meter (A). You can accurately monitor the output level
of left channel on dB scale.
To the right of 3 LEDs you see a retro analog VU meter (B). You can accurately monitor the output level
of right channel on dB scale.

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Lab12 suara 2 x 50W Class A Power Amplifier
Rear Panel
SUARA Rear panel
In rear panel you will find the connection inputs and outputs.
To the right side you will find an IEC AC input including a main fuse holder (C).
A pair of RCA and XLR connectors for each channel (B) are the inputs of signal from your preamplifier.
Speaker outputs for each channel (A) giving you the choice of 4 or 8 ohm output for perfect matching
with your speaker impedance.
Bias setting and check can easily be achieved from the back panel (D). Please find the bias procedure
in page 9.

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Lab12 suara 2 x 50W Class A Power Amplifier
Main connections
Connect a High Grade Power cable to the IEC input and to your wall socket. Make sure that your
wall socket provides a good ground before connecting the power cable.(Every suara is tuned and
calibrated using the Lab12 Knack Power Cable)
Connect to your Preamplifier
Connect the preamplifier analog output to the analog line level input (RCA or XLR cables) of your
suara Power Amplifier. Make sure about the correct channel connections. We suggest you use a
good quality interconnect cable pair.
Connect your Speakers
Connect your speakers to the additional output of suara (connect speakers from 2 to 4 ohm at
4ohm positive bind, speakers from 6 to 16 ohm at 8ohm bind). Make sure about the phase and
polarity of speakers, always connect ‘’plus’’ (red) bind of suara to ‘’plus’’ (red) bind of speaker and
same with black.
Triode / Ultra Linear
You can choose the operation of suara between triode or Ultra Linear pentode mode, to tune the
sound closest to your taste.
This can be done through two toggle switches on the back of power tubes. Position both switches
towards to transformers for triode mode or towards to tubes for Ultra Linear pentode mode.
Always do this selection with your amplifier turned off.
Notes:
Suara is fully compatible with the best octal tubes (6550, KT88, KT120). You can use any of these
three types of tubes with no problem. Please always set correct bias immediately after any tube
change, always use matched pairs of tubes (contact lab12).

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Lab12 suara 2 x 50W Class A Power Amplifier
Bias Setting
Please contact with a qualified person or your local dealer if you are not sure about this
procedure.
You can easily set the bias of each tube from the back panel of amplifier.
You must use a DC multimeter. Please set multimeter in 5vDC range.
Turn on amplifier (with connected speakers at outputs and connected inputs without signal).
Connect minus (black) terminal of multimeter at any minus (black) speaker bind. Connect plus
(red) terminal of multimeter at test point of tube you need to bias.
Use trimming screwdriver to set the voltage at 950mV DC (KT150 setting) from corresponding
trimmer.
Follow the same procedure for each tube.
Wrong bias will destroy your tubes and possibly your amplifier. Always adjust new tubes bias
current immediately after turning on.
Repeat bias procedure at least 3 times the first 5 hours of using.
For the safety of your equipment
! Make sure that all of your equipment is turned off before any connection.
! To avoid damaging your speakers you have to turn on suara some seconds after
turning on your preamplifier and turn it off some seconds before turning off your
preamplifier.
! Never turn on suara without connected speakers or preamplifier on it. It is
possible to damage tubes or even output transformers.

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Lab12 suara 2 x 50W Class A Power Amplifier
Technical Specifications
•Power: 210 - 240VAC 50Hz (110 - 120VAC 60Hz)
•Power consumption: 350 VA max
•Output power: 50 watt per channel (KT 150)
•Frequency response: 20 Hz-25 KHz (-0.9dB)
•Input impedance: 100 K ohms
•Recommended speakers: 4-8 ohm
•Tube complement: 2x 6n1p dual triode, 2x 6n2p, , 4 x KT-150 Power Pentode
•Input sensitivity: 750mV
•Inputs: 1x line unbalanced stereo (RCA and XLR connectors)
•Available colors: Matt Black, Frozen Silver
•Dimensions (WxHxD): 43x19x29 cm
•Weight: 19.5Kg
Warranty
This device has 5 years warranty from the day of purchase for all parts exclude valve tubes.